This CE Center article is no longer eligible for receiving credits.
Commercial roof restoration can present a viable, cost-effective, and environmentally sustainable solution, particularly when a complete tear-off is impractical or unnecessary. In this article, we will discuss the ways in which commercial roofing fails and the process of evaluating whether restoration is the right choice for the project. We will explore key factors to consider when conducting a comprehensive roof assessment as well as delve into important considerations following the initial evaluation, such as project timing, prioritization in relation to other business projects, and future expansion plans. We will discuss the specific steps involved in achieving a proper and durable roof restoration and list applicable codes and opportunities associated with the Inflation Reduction Act. By embracing these practices, you can enhance the longevity of your building, ensuring genuine sustainability while recognizing that roof coatings and restoration methods may not be suitable for every structure. This comprehensive approach empowers you to make well-informed decisions regarding your roofing needs.
All images courtesy of ICP
It is essential for contractors and building owners to discern when renovation is appropriate and when more extensive measures are necessary.
Roofing Overview
Renovating a roof brings a range of advantages that set it apart from traditional repair, recovering, or reroofing methods. It can offer a cost-effective solution, as it typically requires less material and labor compared to complete replacement. It also allows for customization and aesthetic enhancements without too much invasive work. Additionally, renovating a roof can often be completed with minimal disruption to the occupants, reducing the inconvenience and hassle associated with extensive construction projects. When it comes to addressing roofing issues, renovation can often emerge as a compelling choice, offering a reasonable alternative to complete recovering or reroofing.
However, for contractors and building owners alike, it is crucial to discern when renovation is a viable solution or when it is better to opt for more extensive measures. Understanding the key indicators and factors that determine the feasibility of renovation versus other options is paramount, ensuring that roofing systems receive the appropriate treatment they require. In this section we will look at a few different types of commercial roofing materials and the unique failures and issues they can experience over time and discuss solution basics. By recognizing the specific vulnerabilities associated with different roofing types, contractors can accurately evaluate whether renovation is a suitable option.
Metal Roofing Failures
High humidity, saltwater exposure, acidic rain, and chemical pollutants can speed up the metal's decay, leading to weakened structure, leaks, and perforations in the roof.
Metal roofing is a popular and durable roofing option known for its longevity, strength, and versatility. It has high-level resistance to various weather conditions, including strong winds, heavy rain, and snow. Metal roofs are also fire-resistant, providing an added layer of safety and protection. They tend to be low maintenance, requiring minimal upkeep compared to other roofing materials, and they are less susceptible to rot, insect damage, and mold growth.
Additionally, metal roofs are energy-efficient, as they reflect sunlight, reducing heat absorption and keeping the building cooler in warm climates. This can contribute to lower energy costs for cooling. In general, metal roofs are considered environmentally friendly, often containing a high percentage of recycled materials and being fully recyclable at the end of their lifespan. Each type of metal roofing has its own unique characteristics, advantages, and considerations.
While metal roofing is known for its durability and longevity, certain failures or issues can still occur. Although metal roofing materials are generally resistant to corrosion, prolonged exposure to certain environmental conditions can lead to corrosion over time. Factors such as high humidity, saltwater exposure, acidic rain, or chemical pollutants can accelerate the corrosion process. Corrosion can weaken the metal, compromise its structural integrity, and eventually lead to leaks or perforations in the roof.
Metal roofs are typically secured with fasteners such as screws or nails. Over time, these fasteners can become loose or even dislodged due to factors such as expansion and contraction caused by temperature fluctuations or the movement of a building’s structure. Loose or missing fasteners can cause panels to lift, resulting in gaps that allow water infiltration and wind damage.
In standing seam metal roofs, where panels are connected by interlocking seams, seam failure can occur if the seams are not properly installed or if the metal undergoes excessive movement. Seam failure can lead to water penetration and subsequent leaks.
Metal roofing materials expand and contract with temperature changes. Over time, this thermal movement can cause stress on fasteners, seams, and other roof components. If the roofing system is not designed or installed to accommodate thermal expansion and contraction, it can result in buckling, warping, or stress fractures in the metal panels.
Another potential issue is galvanic corrosion, which occurs when two dissimilar metals come into contact in the presence of an electrolyte, such as water or moisture. This can happen when incompatible metals, such as aluminum and steel, are used together in a metal roofing system without proper insulation or separation. Galvanic corrosion can lead to accelerated metal degradation and premature failure.
Roofing penetrations such as skylights, chimneys, vent pipes, and solar panels automatically complicate roofing systems by providing a potential entry point for water. If installation and flashing are not done correctly, it can result in leaks and water damage to the roof structure, insulation, and interior spaces.
Single-Ply Roofing Failures
Single-ply membranes can be vulnerable to punctures, tears, or cuts during installation or maintenance, which can compromise the waterproofing integrity of the roof.
Single-ply roofing refers to roofing systems that consist of a single layer of flexible and durable membrane material. This type of roofing offers several advantages, including ease of installation, energy efficiency, and versatility. Examples of single-ply roofing include ethylene propylene diene monomer (EPDM), thermoplastic olefin (TPO), and polyvinyl chloride (PVC).
EPDM is a synthetic rubber membrane known for its excellent resistance to UV radiation, ozone, and weathering. It is flexible, durable, and can withstand a wide range of temperatures. EPDM membranes are commonly available in large sheets that can be mechanically fastened, fully adhered, or ballasted.
TPO is a single-ply membrane popular for its energy efficiency, reflectivity, ease of installation and low cost. It provides excellent resistance to UV radiation, heat, and chemical exposure. TPO membranes are typically available in rolls and can be mechanically fastened, fully adhered, or heat-welded.
PVC roofing membranes are made of a thermoplastic material and offer excellent durability, chemical resistance, and fire resistance. They are known for their ability to withstand harsh weather conditions, including high winds and hail. PVC membranes are available in rolls and can be mechanically fastened or fully adhered. Heat-welding is the most common method of seaming PVC membranes.
When it comes to single-ply roofing, whether the membrane is heat welded or chemically welded, the seam is highly vulnerable to failure. If the seams are not properly installed, sealed, or maintained, there can be major issues. Common issues include open or poorly adhered seams, separation, or seam disintegration, which can lead to water infiltration and leaks.
Single-ply membranes can be vulnerable to punctures, tears, or cuts, which can compromise the waterproofing integrity of the roof. Damage can occur during installation, maintenance activities, or as a result of external factors such as foot traffic, falling debris, or severe weather conditions. Flashings are crucial components of single-ply roofing systems that can also produce problems. Flashings provide waterproofing around roof penetrations, edges, and transitions, but improperly installed or deteriorated flashings can result in water penetration, compromising the roof’s integrity and causing leaks.
Single-ply membranes can be attached to the roof substrate through various methods, such as mechanical fastening or adhesive bonding. If the attachment is inadequate or if fasteners become loose or dislodged over time, it can lead to membrane uplift, billowing, or even complete detachment in severe cases. These systems can also be susceptible to chemical degradation caused by exposure to certain substances, such as oils, solvents, acids, or cleaning agents. Chemical degradation can result in membrane weakening, discoloration, embrittlement, or loss of flexibility, ultimately compromising the roof’s performance.
UV radiation from the sun can gradually degrade the surface of single-ply membranes, especially those without adequate UV stabilizers or protective coatings. UV degradation can lead to the loss of membrane flexibility, cracking, blistering, or deterioration, reducing the roof’s overall lifespan.
As with any roofing system, improper installation practices breed failure. A range of issues with single-ply roofing systems can occur including inadequate substrate preparation, incorrect application of adhesives or seam sealants, improper flashing installation, or failure to follow manufacturer guidelines. These issues also may include poor adhesion, weak seams, or compromised waterproofing.
Built-up/Mod-bit Roofing Failures
Small cracks on the mod-bit membrane surface—referred to as “alligatoring” can occur due to age, weathering, or UV exposure.
Built-up roofing (BUR), also known as a “tar and gravel” roof, is the traditional type of flat or low-slope roofing system composed of multiple layers of bitumen (asphalt or coal tar) and reinforcing materials that create a durable and waterproof roof membrane. Mod-bit roofing, short for modified bitumen roofing, is a type of flat or low-slope roofing system that is commonly used in commercial, industrial, and residential applications. It is a modern variation of the BUR system, combining the benefits of BUR with technological advancements.
Mod-bit roofing consists of a reinforced bitumen membrane modified with polymers for enhanced performance. The primary component of mod-bit roofing is the bitumen membrane, which provides waterproofing and weatherproofing properties. This type of roofing provides an effective solution for flat or low-slope roofs, combining the benefits of BUR with improved performance and ease of installation. And while BUR/mod-bit systems are durable, they have their own vulnerabilities.
Blistering is a common issue with mod-bit roofing and occurs when air or moisture becomes trapped between the layers of the membrane. It can be caused by improper installation, inadequate substrate preparation, or excessive heat during application. Blistering can lead to membrane delamination, reduced waterproofing effectiveness, and potential leaks.
Mod-bit roofing membranes have seams where the individual rolls or sheets are joined together. If the seams are not properly installed, sealed, or maintained, they can be prone to failure. Common seam issues include open or poorly adhered seams, separation, or seam disintegration, which can result in water infiltration and leaks.
Another issue is “alligatoring” or cracking, which refers to the formation of a pattern of small cracks on the surface of the mod-bit membrane. It can be caused by age, weathering, or exposure to UV radiation. Cracking can compromise the integrity of the membrane, leading to water penetration and reduced performance.
Ponding water occurs when water accumulates and remains stagnant on the roof surface for an extended period, typically due to inadequate drainage or improper roof slope. Mod-bit roofing systems should be designed to prevent ponding water, as it can lead to membrane deterioration, accelerated aging, and potential leaks. But over time, ponding can occur on even the best-designed surfaces.
Mod-bit roofing membranes can be vulnerable to damage from foot traffic, falling debris, or sharp objects. Punctures, tears, cuts, or abrasions in the membrane can compromise the waterproofing properties of the roof, leading to leaks and potential structural damage.
As with other roofing systems, BUR and mod-bit flashings can become a point of failure. Improperly installed or deteriorated flashings can result in water penetration, compromising the roof’s integrity and causing leaks. In general, improper installation practices can result in a range of issues with mod-bit roofing systems that lead to poor adhesion, weak seams, or compromised waterproofing.
The Four Rs: Repair, Restoration, Recover, Reroof
Restoration can be an easier and more cost-effective way to prolong the life of a roof, but it requires that the original roof is in reasonable condition.
There are different approaches to addressing issues or maintaining a roof’s condition. Factors such as the extent of damage, roof age, budget, and long-term goals will influence the decision between repair, restoration, recover, or reroofing.
Repair Pros and Cons
Roof repair involves fixing specific issues or damage to restore functionality and integrity of a roof. Repairs are typically focused on addressing localized problems, such as leaks, punctures, or flashing issues. Repairs are carried out on a case-by-case basis, targeting the specific areas that require attention. The purpose of repair is to fix the problem and prevent further damage—without necessarily replacing the entire roof. Repair is effective for immediate issues, offers a low-cost option, and can help solve an individual issue in a fairly non-invasive way. The downside is that repairs don’t address any larger issues with a roof, only serving as a bandaid.
Today’s bituminous roofs are ideal for repair because original waterproofing bitumen is easily bonded to new modified repair mastics and coating materials. Additionally, standardized repair procedures have been perfected—following established best practices can return an original roof to peak performance. However, replacement may be a necessity in certain situations, depending on the overall condition of the roof.
Restoration Pros and Cons
Roof restoration is a more comprehensive process than repair and involves rejuvenating an aging or deteriorated roof to extend its lifespan. Restoration typically involves cleaning the roof, repairing any damage, and applying a specialized coating system to enhance the roof’s performance. This approach is commonly used for flat or low-slope roofs and can provide added protection against UV radiation, weathering, and leaks. Restoration is the most cost-effective, least disruptive, and most minimally invasive way to address the entire roof. It also provides an environmentally friendly approach because it prolongs roof life. Restoration is an approach that provides comprehensive repairs and reflective coating for the entire system. Finally, restoration comes with long-term warranties. When considering restoration, however, it must be with a good roof that is in reasonable condition. A highly degraded roof is not a viable candidate for restoration. In addition, restoration may not always be cost-effective, which is why evaluation is important.
Recover Pros and Cons
Recover refers to installing a new roof layer over the existing roof surface. It involves adding a new layer of roofing material on top of the old roof, providing an additional protective barrier. Recover is typically done when the existing roof is structurally sound, but its outer layer has deteriorated or reached the end of its lifespan. The recover process can save time and cost compared to a complete roof replacement, as it eliminates the need to remove the existing roof. For this reason, too, it is more environmentally friendly than a full reroof. As with restoration, recovers provide a fully reflective roofing system that repairs can’t achieve, but at a lower cost than reroofing—though it should be noted that some of the KEE formulas do tan out, and if roofs are not properly maintained the reflective element will degrade. Like restoration, recovers come with long-term warranties—anywhere from 10 to 20 years. On the downside, a recover can only be done once. Once you do a recover on a roof, that is your second layer and the National Roofing Code won’t allow for another layer on top of the recover. Just as with restoration, recovers can only be done with roofs that are in good condition, otherwise the system will fail prematurely.
The weight of the roof must also be considered when recovering, because the additional weight of the new roofing materials can put stress on the underlying structure of the building. The structural capacity of the building is designed to support a certain amount of weight, including the original roof load. In addition, if there are pre-existing structural deficiencies in the building, such as weak or deteriorated roof trusses, compromised walls, or inadequate support systems, adding more weight through recovering can exacerbate these issues. Building codes and regulations set specific guidelines regarding the maximum weight that a building’s structure can support. Compliance with building codes is essential to ensure the safety and integrity of the structure. Depending on what is already there, layers of roof or gravel may need to come off to help with weight issues.
Reroofing Pros and Cons
Reroofing involves completely replacing an existing roof system with a new one. It includes removing the old roof layers down to the roof deck and installing a new roof covering. Reroofing is necessary when the existing roof has extensive damage, is structurally compromised, or has reached the end of its lifespan. It provides the opportunity to upgrade the roofing system, improve insulation, or change a roof’s design. There are definite advantages to reroofing. Reroofing removes a bad roof from the deck up, which allows you to evaluate the entire roof deck surface. And because it is a new system, a reroof brings everything up to current code and provides a brand-new warranty. On the downside, reroofing requires careful planning and is typically more expensive and time-consuming than recovering or repairs. It is not as environmentally friendly, because all the material from the old roof is being put in a landfill and new material is being used—which will also, eventually, end up in the landfill. It is the most invasive solution and poses the most liability for contractors during installation since whole sections of the roof will be open and exposed.
Section 2: How Do You Decide?
Assessing
Ponding water is a detail easily identified during a visual assessment, and which could indicate structural sagging in the deck.
Assessing the condition of a roof is crucial when making decisions about whether to repair, restore, recover, or reroof. A visual inspection is a basic and initial assessment method. Initially, this will involve clearing off any trash or accumulated debris that might inhibit a complete visual inspection. Fully vacuuming dirt and gravel from the roof’s surface will grant an even clearer picture. From there, some clues may become easily apparent to the naked eye:
- A soft area underfoot is an indicator of saturated insulation.
- Rusted, rotted, or cracked decking can sometimes be seen from the inside of the building and may help locate the worst areas of deck deterioration.
- Ponding water could indicate structural sagging in the deck.
- A splitting membrane may be visible to the naked eye for experienced professionals.
While a visual inspection provides a general idea of the roof’s condition, it may not uncover hidden or underlying issues. To gain a more thorough assessment of wet insulation, infrared photography can be deployed to uncover what the naked eye can’t see. Infrared thermography, also known as thermal imaging, is a non-destructive testing method that utilizes infrared cameras to detect and capture the thermal patterns emitted by an object or surface. Small, hand-held infrared cameras tend to be a good choice for smaller roofs, while ariel infrared photography—if available—is effective with large roofs.
One of the primary uses of infrared thermography in roof evaluation is the detection of moisture intrusion. Wet areas on a roof surface retain and dissipate heat differently than dry areas, creating temperature variations. By capturing thermal images of the roof, infrared cameras can identify these temperature anomalies, indicating potential areas of moisture infiltration. This enables early detection of leaks or areas where water is trapped within the roof system.
Infrared thermography can help assess the energy efficiency of a roof by detecting areas of heat loss or inadequate insulation. Thermal imaging can identify temperature differences between well-insulated and poorly insulated areas, allowing you to pinpoint locations where heat is escaping from a building. This information helps identify areas that require additional insulation or sealing to improve energy efficiency and reduce heating or cooling costs.
By conducting an infrared scan of a roof, the overall integrity of the roofing system can be assessed. The thermal images can reveal potential defects, such as deteriorated or damaged roofing materials, inadequate sealing around penetrations, or compromised flashing. These findings can help identify areas that require repair or maintenance, preventing further damage to the roof and potential water intrusion. It’s an approach that allows for non-contact evaluation of a roof, eliminating the need for physical access to hazardous or hard-to-reach areas. This makes the inspection process safer and more efficient.
Once your visual inspection is complete, drawing up a detailed roof plan is a good next step. GPS systems can speed up this process, especially if you’re drawing plans for a very large facility or complex. Instruments commonly used in the surveying industry can be used to pinpoint roof equipment and leaking areas.
Infrared thermography is the cheapest and quickest method to identify thermal anomalies in the roof. It won’t identify a wet spot in the roof—that must be verified through core testing or a moisture probe. But it will provide a broad view of the roofing system.
Resistance testing and nuclear testing – both are legitimate tests but must be field verified by either a core test and moisture probe or core test and lab testing to determine the percentage of moisture. As you are testing, keep in mind that if 20-25 percent of the roof is wet, it will probably require a tear-off to bring the roof up to code. In particular, the National Roofing Code allows only 5 percent moisture in the membrane and 8 percent in the insulation, which is why it is important in this part of the assessment to determine what areas of the roof are wet and how much.
Peel Adhesion Testing
A peel adhesion test is based on Miami-Dade’s rigorous testing protocols, but its parameters, such as peel angle, speed, and sample dimensions, may vary depending on the testing standards or specifications.
With your visual inspection complete and a roof plan in hand, you can verify your findings through a series of testing. If, at this point, restoration seems like it could be an option, a peel adhesion test can be conducted. This test helps determine the viability of coating solutions by assessing the bonding capability of the roof and the need for an adhesive primer.
How to do a peel adhesion test:
- Make sure that the surface is clean and dry.
- Apply a base coat of the coating.
- Embed a polyester.
- Attach a clip to the end of the fabric.
- Attach a spring scale to the clip.
- Pull the scale at a 180 percent angle (the same plane as the roof surface).
- Test values over 2 pounds/inch width are acceptable for coating applications.
- Look for points of failure.
This particular test is based on Miami-Dade’s rigorous testing protocols. It’s important to note that the specific test parameters, such as peel angle, speed, and sample dimensions, may vary depending on the testing standards or specifications provided by manufacturers, industry organizations, or testing laboratories. By conducting peel adhesion tests, roofing professionals can evaluate the bonding performance of the roof system, assess the quality of the adhesive used, and ensure that the roofing membrane will be securely attached to the substrate during the renovation.
Core Cutting Testing
Core cutting, while destructive, can be eye opening. It helps validate the visual moisture survey and confirm how many layers of roofing exist. It involves the extraction of cylindrical sections, or cores, from the roof structure to assess various properties such as composition, condition, and performance. Core cutting requires specialized equipment and tools, most importantly a core drill, which is a handheld or machine-operated drilling device designed for this purpose. Once the core has been cut, it is carefully extracted from the roof and transported to a laboratory for further analysis and testing. The specific tests conducted on the core samples can vary based on the objectives of the study, but they may include assessments of material properties, adhesion strength, moisture content, or chemical composition.
It will reveal the type of deck, how many layers of roof there are, and the type of insulation in the roof, which all helps determine whether restoration is a valid option. Or, if you were considering a recover, the core would be able to tell you if there are already two layers—in which case a third could not be applied.
After the core sample has been taken, the hole created by the core drill is patched and repaired using appropriate roofing materials and techniques. This ensures that the roof’s integrity is maintained and that there are no leaks or vulnerabilities caused by the core cutting process. It’s important to note that the core cutting process should be performed by trained professionals with expertise in roofing systems to ensure safety, accuracy, and minimal disruption to the roof structure.
Wind Uplift Testing
Wind uplift testing can be used to determine the state of the membrane—remember that membranes can become decimated by a storm but may stay in place. The next “big one,” however, can finish the job by ripping the membrane completely off the structure. If you are considering a fleece-backed PVC over the top of a granular modified, you can apply your adhesive and do a pull test to determine if the structural components of the roof meet the required uplift codes to put that roof over it.
During the pull test, the force required to dislodge or pull out the fastener from the substrate is measured. This measurement is usually recorded in pounds or newtons. It indicates the fastener’s resistance to the upward forces exerted by high winds, representing its ability to maintain its position and secure the roofing components. As with a peel adhesion test, a pull test is compared against established pass/fail criteria. If the roofing system can withstand the applied uplift forces without failure or significant displacement beyond the acceptable limits, it is considered to have passed the test.
Structural Engineer
Finally, a licensed structural engineer should be retained if there is any evidence of structural failure or additional loading on the roof (condensing units, blowers, metal screens, ballasted antennas, etc.). A structural engineer can assess the condition of the existing roof structure, including the supporting components, such as beams, trusses, and load-bearing walls. They can identify any structural issues, weaknesses, or damage that may affect the stability and integrity of the roof. This evaluation ensures that any renovation or reroofing work is based on a sound and stable structure.
In terms of loading, roofing materials can be heavy, especially when multiple layers are involved. A structural engineer can evaluate the load-bearing capacity of the existing roof structure and determine if it can support the additional weight of a new roofing system. They consider factors such as the materials used, local building codes, and the design of the building. This analysis helps prevent overloading the structure and potential structural failures.
An evaluation by a structural engineer provides an in-depth understanding of the existing roof structure, its capacity, and its compatibility with the proposed renovation or re-roofing plans. Their expertise helps ensure the structural integrity, compliance with building codes, and optimal performance of the roof, leading to a safe, durable, and cost-effective solution for the building owner or operator.
Analyzing
Roofs with low to moderate damage or good candidates for restoration, but a reroof will be required when roofs are extremely damaged.
With your roof inspection complete, it’s time to determine a path forward. Roofs with low to moderate damage and saturation levels are often good candidates for roof restoration rather than a full recover, and they can be a cost-effective option when the circumstances call for it. Reroofs will be required in more extreme scenarios, with elevated levels of insulation saturation, decking deterioration, and more. As stated before, a good rule of thumb is that any roof that is more than 20 percent saturated is deemed a full tear-off, per many national building codes and standards.
In addition to the level of damage uncovered during inspection, there are some additional considerations that should be made when determining the right repair technique for your project. Some of these include:
What is the anticipated lifespan of the building? Not every structure merits the same level of repair work. A small retail store that sits in the path of a proposed freeway expansion, for example, might not need a repair that ensures 20 years of performance. A major museum in the hub of a cultural district, by contrast, will require a long-term solution. In either case, proven repair solutions are available to best suit the needs of the given situation.
Are there plans to expand the building in the near future? It’s generally more economical to reroof a structure in conjunction with an expansion rather than split the project across multiple years. The need for roof access and impact to building operations can be greatly reduced if both projects can be performed at the same time.
Where and at what time of year will the work be done? A 30-story condo tower in Florida has very different wind, thermal shock, thermal bridging, and UV exposure than a single-story industrial plant in the Midwest. These types of conditions should be considered when developing a repair or replacement plan.
What is the building use and type? Different types of buildings serve various functions and have specific requirements for their roofing systems. For example, a commercial office building may have different needs than a residential home or an industrial facility. Building codes and regulations also vary depending on the building type and use, as well as aesthetic considerations. A hospital and operating room may look completely different from a restoration over the top of a warehouse that houses empty paint cans, for example. And the type and use of the building can influence the budgetary considerations when deciding whether to repair, renovate, recover, or reroof the roofing system.
The Case for Restoration
A 30-story condo tower in Florida would require a different roofing approach than a single-story industrial plant in the Midwest.
Your determination of the right repair method will depend on the specific circumstances of the job at hand. In situations where restoration is appropriate, you’ll find some significant advantages versus reroofing or other alternative repair measures.
Restoration generally requires far less specialized equipment and does not leave the building interior exposed while the job takes place. A good roof restoration process involves removing any debris and cleaning the roof to prepare for the rest of the project. Next, depending on the condition of the roof, a primer is applied to ensure good adhesion for patching, stain blocking, and rust inhibition. Then, patching is performed to make sure all parts of the roof system are watertight. Finally, protective coatings can be applied to ensure long-lasting performance. All the while, regular activity inside the building can continue uninterrupted.
Restoration jobs can also happen far faster than an entire reroof. For contractors, time is money. If you can successfully bring an existing roof back up to its original performance level with restoration methods, you can move on to your next job more quickly. A restoration project can be undertaken with the purchase of just a few high-performance products, a far more cost-effective solution than replacing the roof entirely. Full restorations on average range between $400- to $700-per-square, while tear-off and replacement starts at $1,000-per-square and can go up from there depending on region and project complexity.
For a restoration project to meet its full potential, you can also work with the trusted supplier of high-performance coatings and mastics to help ensure a job well done. Modern mastic formulations are able to deliver outstanding performance that building owners can rely on for the long term. The right supplier may also be able to help you ensure best practices are followed on your next job, leading to more satisfied customers.
Section 3: Common Restoration Practices
With metal roofs, it is important to focus on seams, fasteners, and penetrations during the renovation process.
Adhering to best practices is of utmost importance when undertaking a roof renovation. These practices ensure that the renovation project is executed with precision, quality, and safety, leading to a successful outcome. Following best practices, such as conducting a thorough inspection, testing, selecting appropriate materials, and addressing underlying issues, helps mitigate potential problems and ensures that the renovated roof performs optimally for years to come. Best practices promote compliance with local building codes and regulations, ensuring that the renovation meets the necessary standards.
Metal Roofing Restoration
When it comes to restoring metal roofing, it is important to focus on seams, fasteners, and penetrations. Seams are important to protect against wind-driven rain, and if there is a poor seal or improper install, water intrusion becomes an issue. There are many theories on how to treat horizontal and vertical seams, including taping seams, lifting panels, and sealing underneath or brushing adhesive over the top. Every manufacturer has their own recommendation for both horizontal and vertical seams that should be followed.
During the restoration process look for loose fasteners, which should be removed and replaced with new fasteners. The new fasteners should be one size larger than the original one and attached with a new screw. Once the new fastener is in, apply a layer of mastic over the top of it and a secondary sealant on top of the mastic.
Next, address all penetrations, such as skylights, curbs, roof fence, and plumbing vents. If penetrations show signs of damage, such as rust, corrosion, leaks, or compromised seals, contractors should undertake the necessary repairs or consider replacing the damaged components. This may involve fixing or replacing flashing, gaskets, or seals around the penetrations to ensure watertightness and proper integration with the restored roof system. Contractors should ensure that flashing materials are correctly installed and integrated with the metal roofing system to prevent water infiltration and provide long-term protection.
Contractors may need to apply appropriate sealants or caulking around penetrations as part of the restoration process. This helps reinforce the waterproofing and weatherproofing capabilities of the penetrations and ensures a secure bond between the roofing materials and the penetrations. In general, they should ensure that any repair materials, sealants, or coatings used for penetrations are compatible with the specific metal roofing system and the materials surrounding the penetrations, especially because metal roofs expand and contract.
Single-Ply Restoration
With single-ply, it is important to look at tie-ins where the membrane transitions to other roofing components.
Single-ply roofing is a welded system—either heat or chemically welded—and for this reason, seams must be addressed. Self-adhered tape is one way to restore single-ply roofing, but as always, pay attention to what the manufacturer suggests.
With single-ply restoration it is also important to look at tie-ins where the membrane transitions to other roofing components. Flashing tie-ins, penetration tie-ins, edge tie-ins, roof-to-wall tie-ins, and expansion joint tie-ins are all critical to preventing water intrusion. Look for any issues around curves and the inside or outside corners. Other common problems seen with single-ply membranes include splits and burns, as well as repair issues with base flashings, curbs, and corners. Restoration for single-ply membrane systems typically requires adhesive repair tape or other minor reinforcement approaches.
Single-ply membranes are often exposed to UV radiation. Contractors may select coatings or treatments that enhance UV resistance and protect the membrane from UV degradation and premature aging.
BUR/Modified Bitumen Restoration
When renovating a BUR/mod-bit system, contractors should look for signs of blistering, cracking, or granule loss, which may require repairs or preparation before restoration work can commence. Take note of all penetrations, such as chem curbs, pitch pockets, slash penetrations, and any other vulnerable areas. Pay attention to drains and other waterways, as well as metal edges. Common issues on BUR and mod-bit are located at penetrations and field seams. If it is a gravel BUR system, look for lines of gravel where splits in the system have occurred and repair the splits.
The Four Steps of Restoration (Four Ps)
Once you decide to restore a roofing system, contractors should stick to the Four Ps of Restoration: Prep it, prime it, patch it and protect it. These steps are required for a full restoration system and leaving any one out risks potential failure of the restoration.
Prep
Remove any debris and clean the roof to prepare for the rest of the project. This might entail sweeping, brooming, blowing, pressure washing, taping off areas, and closing off air intakes. This is an important step. Nothing will be successful if this step is not done properly. One of the most common mistakes with roofing restoration is not cleaning or letting the substrate dry. If there is dew on the substrate and a contractor merely blows debris off the surface before priming, moisture could be embedded in the system and cause premature problems.
Prime
Depending on the condition of the roof, a primer is applied to ensure good adhesion for patching, stain blocking and rust inhibition. Primers are most commonly used for stain blocking and adhesion, but with metal roofing systems, rust inhibition primers are important. They help ensure that whatever restoration system is going on top will have a good bond.
In some instances, like with restaurants where grease may be present, a bleed blocking primer can be used to prevent oils from emerging. These primers have solvent in them to keep coatings white.
Patch
Patching is performed to make sure all parts of the roofing are watertight. This is the phase where contractors must pay attention to penetrations, flashing, field seams, and physical damage. Sometimes coatings have been sold as stand-alone water proofers, but that is not the case. Putting a coating over a bad seam without properly preparing it for expansion and contraction will ensure it becomes a bad seam again. Patching should have a mastic base, followed by a coating and embedded polyester, and then a top coat over it. Follow the manufacturer's instructions to apply this patching method.
Protect
The sun produces radiant heat and powerful UV rays that cause thermal shock and rapid deterioration of all roofing materials. This constant exposure results in accelerated aging, lost flexibility, fatigue, splits, cracks and ultimately roof membrane failure. Reflective and protective coatings can be applied to ensure long-lasting performance. All the while, regular activity inside the building can continue uninterrupted. Silicone coating is a good choice for roofing systems that have issues with ponding (though roofs should not be ponding at all). If it is late in the year and you are worried about cool weather, silicone is a good protection option for metal roof restoration.
Silicones and acrylics both have their advantages and disadvantages. Acrylics are more walkable when wet while silicones have a much longer durability and lifespan.
Heat buildup in a roof can also lead to increased building temperatures, building discomfort, unproductive employees and increased energy consumption. Cool roof systems act like a reflective shield to protect the roof membrane. Cool roof systems drastically reduce roof temperatures, thermal shock and heat transfer. In addition, they extend roof life, improve building comfort and substantially reduce cooling costs. And, in the long run, this helps building owners see a much greater return on their investment.
Section 4: Roofing Codes and Tax Incentives
The 2021 International Building Code (IBC) provides requirements for roofing, including materials, installation, and renovation. Roofing renovation typically requires obtaining the necessary permits from the local building department. The IBC doesn’t specify the exact process but provides guidelines for compliance with local regulations.
The IBC provides guidance on structural design and load requirements to ensure safety and performance for renovations. It also includes provisions for weather resistance and water shedding capabilities of roofing materials. These requirements aim to ensure the durability and performance of the roof system. Depending on the building’s type and occupancy, the IBC may specify fire resistance requirements for roofing materials.
The IBC includes provisions related to energy efficiency in buildings, which address insulation, ventilation, and reflective properties of the roof to minimize heat gain or loss.
Specific details and requirements for roofing renovation does depend on the local jurisdiction and the specific circumstances of a project, so contractors should consult the relevant local building code or consult with an expert to ensure compliance with local regulations.
Inflation Reduction Act (IRA) Opportunities
Roof maintenance systems have some tax benefits. They are fully tax deductible for building owners as an operating expense. A key advantage of a restoration system over a new roof system is how they are classified by the IRS. Because restoration is classified as a maintenance item, in most cases it can be expensed in the accounting period it is incurred. On the other hand, a new roof system is a capital asset that must be amortized over a 39-year life.
Recently, architects, engineers and designers have also gained tax benefits. The 179D Tax Deduction, which provides incentives for energy-efficient building design and construction has undergone significant change in 2023. The maximum reduction will increase to $5-per-square-foot (up from $1.80-per-square-foot). To qualify for the higher tier of deductions, buildings must be constructed with prevailing wage and apprenticeship requirements, and must meet or exceed the ASHRAE Reference Standard 90.1 that was in effect for four years prior to the in-service date of the building. Each additional percentage of energy reduction will increase the deduction by $.10, up to $5.00-per-square-foot.
Designers can obtain 179D Deductions from tax-exempt entities, including public organizations such as K-12 schools, higher education institutions, libraries, municipal buildings, public offices, parking garages, and airport terminals. Other tax-exempt entities, such as charitable organizations, religious institutions, private schools and colleges, non-profit hospitals, private museums, tribal governments, and any other organization falling under 501(c), can also take advantage of the 179D Deduction.
The ability to apply reflective coatings to roof renovations and update insulation provides more than doubles the potential for these tax deductions.
Section 5: Conclusion
When it is appropriate, renovation can provide a compelling alternative to traditional roofing methods that is cost-effective, customizable, and minimally disruptive to occupants.
Renovating a roof presents numerous advantages over traditional repair, recovering, or reroofing methods. Its cost-effectiveness, reduced material and labor requirements, and potential for customization make it an appealing choice, and the minimal disruption it causes to occupants adds to its allure as a viable alternative to extensive construction projects. However, it is essential for contractors and building owners to discern when renovation is appropriate and when more extensive measures are necessary. Understanding key indicators and factors that determine the feasibility of renovation is crucial to ensure that roofing systems receive the suitable treatment they require. By recognizing the unique vulnerabilities of different roofing types, contractors can make informed decisions and accurately assess whether renovation is a suitable option for their specific needs.
Erika Fredrickson is a writer/editor focusing on technology, environment, and history. She frequently contributes to continuing education courses and publications through Confluence Communications. http://www.confluencec.com
Commercial roof restoration can present a viable, cost-effective, and environmentally sustainable solution, particularly when a complete tear-off is impractical or unnecessary. In this article, we will discuss the ways in which commercial roofing fails and the process of evaluating whether restoration is the right choice for the project. We will explore key factors to consider when conducting a comprehensive roof assessment as well as delve into important considerations following the initial evaluation, such as project timing, prioritization in relation to other business projects, and future expansion plans. We will discuss the specific steps involved in achieving a proper and durable roof restoration and list applicable codes and opportunities associated with the Inflation Reduction Act. By embracing these practices, you can enhance the longevity of your building, ensuring genuine sustainability while recognizing that roof coatings and restoration methods may not be suitable for every structure. This comprehensive approach empowers you to make well-informed decisions regarding your roofing needs.
All images courtesy of ICP
It is essential for contractors and building owners to discern when renovation is appropriate and when more extensive measures are necessary.
Roofing Overview
Renovating a roof brings a range of advantages that set it apart from traditional repair, recovering, or reroofing methods. It can offer a cost-effective solution, as it typically requires less material and labor compared to complete replacement. It also allows for customization and aesthetic enhancements without too much invasive work. Additionally, renovating a roof can often be completed with minimal disruption to the occupants, reducing the inconvenience and hassle associated with extensive construction projects. When it comes to addressing roofing issues, renovation can often emerge as a compelling choice, offering a reasonable alternative to complete recovering or reroofing.
However, for contractors and building owners alike, it is crucial to discern when renovation is a viable solution or when it is better to opt for more extensive measures. Understanding the key indicators and factors that determine the feasibility of renovation versus other options is paramount, ensuring that roofing systems receive the appropriate treatment they require. In this section we will look at a few different types of commercial roofing materials and the unique failures and issues they can experience over time and discuss solution basics. By recognizing the specific vulnerabilities associated with different roofing types, contractors can accurately evaluate whether renovation is a suitable option.
Metal Roofing Failures
High humidity, saltwater exposure, acidic rain, and chemical pollutants can speed up the metal's decay, leading to weakened structure, leaks, and perforations in the roof.
Metal roofing is a popular and durable roofing option known for its longevity, strength, and versatility. It has high-level resistance to various weather conditions, including strong winds, heavy rain, and snow. Metal roofs are also fire-resistant, providing an added layer of safety and protection. They tend to be low maintenance, requiring minimal upkeep compared to other roofing materials, and they are less susceptible to rot, insect damage, and mold growth.
Additionally, metal roofs are energy-efficient, as they reflect sunlight, reducing heat absorption and keeping the building cooler in warm climates. This can contribute to lower energy costs for cooling. In general, metal roofs are considered environmentally friendly, often containing a high percentage of recycled materials and being fully recyclable at the end of their lifespan. Each type of metal roofing has its own unique characteristics, advantages, and considerations.
While metal roofing is known for its durability and longevity, certain failures or issues can still occur. Although metal roofing materials are generally resistant to corrosion, prolonged exposure to certain environmental conditions can lead to corrosion over time. Factors such as high humidity, saltwater exposure, acidic rain, or chemical pollutants can accelerate the corrosion process. Corrosion can weaken the metal, compromise its structural integrity, and eventually lead to leaks or perforations in the roof.
Metal roofs are typically secured with fasteners such as screws or nails. Over time, these fasteners can become loose or even dislodged due to factors such as expansion and contraction caused by temperature fluctuations or the movement of a building’s structure. Loose or missing fasteners can cause panels to lift, resulting in gaps that allow water infiltration and wind damage.
In standing seam metal roofs, where panels are connected by interlocking seams, seam failure can occur if the seams are not properly installed or if the metal undergoes excessive movement. Seam failure can lead to water penetration and subsequent leaks.
Metal roofing materials expand and contract with temperature changes. Over time, this thermal movement can cause stress on fasteners, seams, and other roof components. If the roofing system is not designed or installed to accommodate thermal expansion and contraction, it can result in buckling, warping, or stress fractures in the metal panels.
Another potential issue is galvanic corrosion, which occurs when two dissimilar metals come into contact in the presence of an electrolyte, such as water or moisture. This can happen when incompatible metals, such as aluminum and steel, are used together in a metal roofing system without proper insulation or separation. Galvanic corrosion can lead to accelerated metal degradation and premature failure.
Roofing penetrations such as skylights, chimneys, vent pipes, and solar panels automatically complicate roofing systems by providing a potential entry point for water. If installation and flashing are not done correctly, it can result in leaks and water damage to the roof structure, insulation, and interior spaces.
Single-Ply Roofing Failures
Single-ply membranes can be vulnerable to punctures, tears, or cuts during installation or maintenance, which can compromise the waterproofing integrity of the roof.
Single-ply roofing refers to roofing systems that consist of a single layer of flexible and durable membrane material. This type of roofing offers several advantages, including ease of installation, energy efficiency, and versatility. Examples of single-ply roofing include ethylene propylene diene monomer (EPDM), thermoplastic olefin (TPO), and polyvinyl chloride (PVC).
EPDM is a synthetic rubber membrane known for its excellent resistance to UV radiation, ozone, and weathering. It is flexible, durable, and can withstand a wide range of temperatures. EPDM membranes are commonly available in large sheets that can be mechanically fastened, fully adhered, or ballasted.
TPO is a single-ply membrane popular for its energy efficiency, reflectivity, ease of installation and low cost. It provides excellent resistance to UV radiation, heat, and chemical exposure. TPO membranes are typically available in rolls and can be mechanically fastened, fully adhered, or heat-welded.
PVC roofing membranes are made of a thermoplastic material and offer excellent durability, chemical resistance, and fire resistance. They are known for their ability to withstand harsh weather conditions, including high winds and hail. PVC membranes are available in rolls and can be mechanically fastened or fully adhered. Heat-welding is the most common method of seaming PVC membranes.
When it comes to single-ply roofing, whether the membrane is heat welded or chemically welded, the seam is highly vulnerable to failure. If the seams are not properly installed, sealed, or maintained, there can be major issues. Common issues include open or poorly adhered seams, separation, or seam disintegration, which can lead to water infiltration and leaks.
Single-ply membranes can be vulnerable to punctures, tears, or cuts, which can compromise the waterproofing integrity of the roof. Damage can occur during installation, maintenance activities, or as a result of external factors such as foot traffic, falling debris, or severe weather conditions. Flashings are crucial components of single-ply roofing systems that can also produce problems. Flashings provide waterproofing around roof penetrations, edges, and transitions, but improperly installed or deteriorated flashings can result in water penetration, compromising the roof’s integrity and causing leaks.
Single-ply membranes can be attached to the roof substrate through various methods, such as mechanical fastening or adhesive bonding. If the attachment is inadequate or if fasteners become loose or dislodged over time, it can lead to membrane uplift, billowing, or even complete detachment in severe cases. These systems can also be susceptible to chemical degradation caused by exposure to certain substances, such as oils, solvents, acids, or cleaning agents. Chemical degradation can result in membrane weakening, discoloration, embrittlement, or loss of flexibility, ultimately compromising the roof’s performance.
UV radiation from the sun can gradually degrade the surface of single-ply membranes, especially those without adequate UV stabilizers or protective coatings. UV degradation can lead to the loss of membrane flexibility, cracking, blistering, or deterioration, reducing the roof’s overall lifespan.
As with any roofing system, improper installation practices breed failure. A range of issues with single-ply roofing systems can occur including inadequate substrate preparation, incorrect application of adhesives or seam sealants, improper flashing installation, or failure to follow manufacturer guidelines. These issues also may include poor adhesion, weak seams, or compromised waterproofing.
Built-up/Mod-bit Roofing Failures
Small cracks on the mod-bit membrane surface—referred to as “alligatoring” can occur due to age, weathering, or UV exposure.
Built-up roofing (BUR), also known as a “tar and gravel” roof, is the traditional type of flat or low-slope roofing system composed of multiple layers of bitumen (asphalt or coal tar) and reinforcing materials that create a durable and waterproof roof membrane. Mod-bit roofing, short for modified bitumen roofing, is a type of flat or low-slope roofing system that is commonly used in commercial, industrial, and residential applications. It is a modern variation of the BUR system, combining the benefits of BUR with technological advancements.
Mod-bit roofing consists of a reinforced bitumen membrane modified with polymers for enhanced performance. The primary component of mod-bit roofing is the bitumen membrane, which provides waterproofing and weatherproofing properties. This type of roofing provides an effective solution for flat or low-slope roofs, combining the benefits of BUR with improved performance and ease of installation. And while BUR/mod-bit systems are durable, they have their own vulnerabilities.
Blistering is a common issue with mod-bit roofing and occurs when air or moisture becomes trapped between the layers of the membrane. It can be caused by improper installation, inadequate substrate preparation, or excessive heat during application. Blistering can lead to membrane delamination, reduced waterproofing effectiveness, and potential leaks.
Mod-bit roofing membranes have seams where the individual rolls or sheets are joined together. If the seams are not properly installed, sealed, or maintained, they can be prone to failure. Common seam issues include open or poorly adhered seams, separation, or seam disintegration, which can result in water infiltration and leaks.
Another issue is “alligatoring” or cracking, which refers to the formation of a pattern of small cracks on the surface of the mod-bit membrane. It can be caused by age, weathering, or exposure to UV radiation. Cracking can compromise the integrity of the membrane, leading to water penetration and reduced performance.
Ponding water occurs when water accumulates and remains stagnant on the roof surface for an extended period, typically due to inadequate drainage or improper roof slope. Mod-bit roofing systems should be designed to prevent ponding water, as it can lead to membrane deterioration, accelerated aging, and potential leaks. But over time, ponding can occur on even the best-designed surfaces.
Mod-bit roofing membranes can be vulnerable to damage from foot traffic, falling debris, or sharp objects. Punctures, tears, cuts, or abrasions in the membrane can compromise the waterproofing properties of the roof, leading to leaks and potential structural damage.
As with other roofing systems, BUR and mod-bit flashings can become a point of failure. Improperly installed or deteriorated flashings can result in water penetration, compromising the roof’s integrity and causing leaks. In general, improper installation practices can result in a range of issues with mod-bit roofing systems that lead to poor adhesion, weak seams, or compromised waterproofing.
The Four Rs: Repair, Restoration, Recover, Reroof
Restoration can be an easier and more cost-effective way to prolong the life of a roof, but it requires that the original roof is in reasonable condition.
There are different approaches to addressing issues or maintaining a roof’s condition. Factors such as the extent of damage, roof age, budget, and long-term goals will influence the decision between repair, restoration, recover, or reroofing.
Repair Pros and Cons
Roof repair involves fixing specific issues or damage to restore functionality and integrity of a roof. Repairs are typically focused on addressing localized problems, such as leaks, punctures, or flashing issues. Repairs are carried out on a case-by-case basis, targeting the specific areas that require attention. The purpose of repair is to fix the problem and prevent further damage—without necessarily replacing the entire roof. Repair is effective for immediate issues, offers a low-cost option, and can help solve an individual issue in a fairly non-invasive way. The downside is that repairs don’t address any larger issues with a roof, only serving as a bandaid.
Today’s bituminous roofs are ideal for repair because original waterproofing bitumen is easily bonded to new modified repair mastics and coating materials. Additionally, standardized repair procedures have been perfected—following established best practices can return an original roof to peak performance. However, replacement may be a necessity in certain situations, depending on the overall condition of the roof.
Restoration Pros and Cons
Roof restoration is a more comprehensive process than repair and involves rejuvenating an aging or deteriorated roof to extend its lifespan. Restoration typically involves cleaning the roof, repairing any damage, and applying a specialized coating system to enhance the roof’s performance. This approach is commonly used for flat or low-slope roofs and can provide added protection against UV radiation, weathering, and leaks. Restoration is the most cost-effective, least disruptive, and most minimally invasive way to address the entire roof. It also provides an environmentally friendly approach because it prolongs roof life. Restoration is an approach that provides comprehensive repairs and reflective coating for the entire system. Finally, restoration comes with long-term warranties. When considering restoration, however, it must be with a good roof that is in reasonable condition. A highly degraded roof is not a viable candidate for restoration. In addition, restoration may not always be cost-effective, which is why evaluation is important.
Recover Pros and Cons
Recover refers to installing a new roof layer over the existing roof surface. It involves adding a new layer of roofing material on top of the old roof, providing an additional protective barrier. Recover is typically done when the existing roof is structurally sound, but its outer layer has deteriorated or reached the end of its lifespan. The recover process can save time and cost compared to a complete roof replacement, as it eliminates the need to remove the existing roof. For this reason, too, it is more environmentally friendly than a full reroof. As with restoration, recovers provide a fully reflective roofing system that repairs can’t achieve, but at a lower cost than reroofing—though it should be noted that some of the KEE formulas do tan out, and if roofs are not properly maintained the reflective element will degrade. Like restoration, recovers come with long-term warranties—anywhere from 10 to 20 years. On the downside, a recover can only be done once. Once you do a recover on a roof, that is your second layer and the National Roofing Code won’t allow for another layer on top of the recover. Just as with restoration, recovers can only be done with roofs that are in good condition, otherwise the system will fail prematurely.
The weight of the roof must also be considered when recovering, because the additional weight of the new roofing materials can put stress on the underlying structure of the building. The structural capacity of the building is designed to support a certain amount of weight, including the original roof load. In addition, if there are pre-existing structural deficiencies in the building, such as weak or deteriorated roof trusses, compromised walls, or inadequate support systems, adding more weight through recovering can exacerbate these issues. Building codes and regulations set specific guidelines regarding the maximum weight that a building’s structure can support. Compliance with building codes is essential to ensure the safety and integrity of the structure. Depending on what is already there, layers of roof or gravel may need to come off to help with weight issues.
Reroofing Pros and Cons
Reroofing involves completely replacing an existing roof system with a new one. It includes removing the old roof layers down to the roof deck and installing a new roof covering. Reroofing is necessary when the existing roof has extensive damage, is structurally compromised, or has reached the end of its lifespan. It provides the opportunity to upgrade the roofing system, improve insulation, or change a roof’s design. There are definite advantages to reroofing. Reroofing removes a bad roof from the deck up, which allows you to evaluate the entire roof deck surface. And because it is a new system, a reroof brings everything up to current code and provides a brand-new warranty. On the downside, reroofing requires careful planning and is typically more expensive and time-consuming than recovering or repairs. It is not as environmentally friendly, because all the material from the old roof is being put in a landfill and new material is being used—which will also, eventually, end up in the landfill. It is the most invasive solution and poses the most liability for contractors during installation since whole sections of the roof will be open and exposed.
Section 2: How Do You Decide?
Assessing
Ponding water is a detail easily identified during a visual assessment, and which could indicate structural sagging in the deck.
Assessing the condition of a roof is crucial when making decisions about whether to repair, restore, recover, or reroof. A visual inspection is a basic and initial assessment method. Initially, this will involve clearing off any trash or accumulated debris that might inhibit a complete visual inspection. Fully vacuuming dirt and gravel from the roof’s surface will grant an even clearer picture. From there, some clues may become easily apparent to the naked eye:
- A soft area underfoot is an indicator of saturated insulation.
- Rusted, rotted, or cracked decking can sometimes be seen from the inside of the building and may help locate the worst areas of deck deterioration.
- Ponding water could indicate structural sagging in the deck.
- A splitting membrane may be visible to the naked eye for experienced professionals.
While a visual inspection provides a general idea of the roof’s condition, it may not uncover hidden or underlying issues. To gain a more thorough assessment of wet insulation, infrared photography can be deployed to uncover what the naked eye can’t see. Infrared thermography, also known as thermal imaging, is a non-destructive testing method that utilizes infrared cameras to detect and capture the thermal patterns emitted by an object or surface. Small, hand-held infrared cameras tend to be a good choice for smaller roofs, while ariel infrared photography—if available—is effective with large roofs.
One of the primary uses of infrared thermography in roof evaluation is the detection of moisture intrusion. Wet areas on a roof surface retain and dissipate heat differently than dry areas, creating temperature variations. By capturing thermal images of the roof, infrared cameras can identify these temperature anomalies, indicating potential areas of moisture infiltration. This enables early detection of leaks or areas where water is trapped within the roof system.
Infrared thermography can help assess the energy efficiency of a roof by detecting areas of heat loss or inadequate insulation. Thermal imaging can identify temperature differences between well-insulated and poorly insulated areas, allowing you to pinpoint locations where heat is escaping from a building. This information helps identify areas that require additional insulation or sealing to improve energy efficiency and reduce heating or cooling costs.
By conducting an infrared scan of a roof, the overall integrity of the roofing system can be assessed. The thermal images can reveal potential defects, such as deteriorated or damaged roofing materials, inadequate sealing around penetrations, or compromised flashing. These findings can help identify areas that require repair or maintenance, preventing further damage to the roof and potential water intrusion. It’s an approach that allows for non-contact evaluation of a roof, eliminating the need for physical access to hazardous or hard-to-reach areas. This makes the inspection process safer and more efficient.
Once your visual inspection is complete, drawing up a detailed roof plan is a good next step. GPS systems can speed up this process, especially if you’re drawing plans for a very large facility or complex. Instruments commonly used in the surveying industry can be used to pinpoint roof equipment and leaking areas.
Infrared thermography is the cheapest and quickest method to identify thermal anomalies in the roof. It won’t identify a wet spot in the roof—that must be verified through core testing or a moisture probe. But it will provide a broad view of the roofing system.
Resistance testing and nuclear testing – both are legitimate tests but must be field verified by either a core test and moisture probe or core test and lab testing to determine the percentage of moisture. As you are testing, keep in mind that if 20-25 percent of the roof is wet, it will probably require a tear-off to bring the roof up to code. In particular, the National Roofing Code allows only 5 percent moisture in the membrane and 8 percent in the insulation, which is why it is important in this part of the assessment to determine what areas of the roof are wet and how much.
Peel Adhesion Testing
A peel adhesion test is based on Miami-Dade’s rigorous testing protocols, but its parameters, such as peel angle, speed, and sample dimensions, may vary depending on the testing standards or specifications.
With your visual inspection complete and a roof plan in hand, you can verify your findings through a series of testing. If, at this point, restoration seems like it could be an option, a peel adhesion test can be conducted. This test helps determine the viability of coating solutions by assessing the bonding capability of the roof and the need for an adhesive primer.
How to do a peel adhesion test:
- Make sure that the surface is clean and dry.
- Apply a base coat of the coating.
- Embed a polyester.
- Attach a clip to the end of the fabric.
- Attach a spring scale to the clip.
- Pull the scale at a 180 percent angle (the same plane as the roof surface).
- Test values over 2 pounds/inch width are acceptable for coating applications.
- Look for points of failure.
This particular test is based on Miami-Dade’s rigorous testing protocols. It’s important to note that the specific test parameters, such as peel angle, speed, and sample dimensions, may vary depending on the testing standards or specifications provided by manufacturers, industry organizations, or testing laboratories. By conducting peel adhesion tests, roofing professionals can evaluate the bonding performance of the roof system, assess the quality of the adhesive used, and ensure that the roofing membrane will be securely attached to the substrate during the renovation.
Core Cutting Testing
Core cutting, while destructive, can be eye opening. It helps validate the visual moisture survey and confirm how many layers of roofing exist. It involves the extraction of cylindrical sections, or cores, from the roof structure to assess various properties such as composition, condition, and performance. Core cutting requires specialized equipment and tools, most importantly a core drill, which is a handheld or machine-operated drilling device designed for this purpose. Once the core has been cut, it is carefully extracted from the roof and transported to a laboratory for further analysis and testing. The specific tests conducted on the core samples can vary based on the objectives of the study, but they may include assessments of material properties, adhesion strength, moisture content, or chemical composition.
It will reveal the type of deck, how many layers of roof there are, and the type of insulation in the roof, which all helps determine whether restoration is a valid option. Or, if you were considering a recover, the core would be able to tell you if there are already two layers—in which case a third could not be applied.
After the core sample has been taken, the hole created by the core drill is patched and repaired using appropriate roofing materials and techniques. This ensures that the roof’s integrity is maintained and that there are no leaks or vulnerabilities caused by the core cutting process. It’s important to note that the core cutting process should be performed by trained professionals with expertise in roofing systems to ensure safety, accuracy, and minimal disruption to the roof structure.
Wind Uplift Testing
Wind uplift testing can be used to determine the state of the membrane—remember that membranes can become decimated by a storm but may stay in place. The next “big one,” however, can finish the job by ripping the membrane completely off the structure. If you are considering a fleece-backed PVC over the top of a granular modified, you can apply your adhesive and do a pull test to determine if the structural components of the roof meet the required uplift codes to put that roof over it.
During the pull test, the force required to dislodge or pull out the fastener from the substrate is measured. This measurement is usually recorded in pounds or newtons. It indicates the fastener’s resistance to the upward forces exerted by high winds, representing its ability to maintain its position and secure the roofing components. As with a peel adhesion test, a pull test is compared against established pass/fail criteria. If the roofing system can withstand the applied uplift forces without failure or significant displacement beyond the acceptable limits, it is considered to have passed the test.
Structural Engineer
Finally, a licensed structural engineer should be retained if there is any evidence of structural failure or additional loading on the roof (condensing units, blowers, metal screens, ballasted antennas, etc.). A structural engineer can assess the condition of the existing roof structure, including the supporting components, such as beams, trusses, and load-bearing walls. They can identify any structural issues, weaknesses, or damage that may affect the stability and integrity of the roof. This evaluation ensures that any renovation or reroofing work is based on a sound and stable structure.
In terms of loading, roofing materials can be heavy, especially when multiple layers are involved. A structural engineer can evaluate the load-bearing capacity of the existing roof structure and determine if it can support the additional weight of a new roofing system. They consider factors such as the materials used, local building codes, and the design of the building. This analysis helps prevent overloading the structure and potential structural failures.
An evaluation by a structural engineer provides an in-depth understanding of the existing roof structure, its capacity, and its compatibility with the proposed renovation or re-roofing plans. Their expertise helps ensure the structural integrity, compliance with building codes, and optimal performance of the roof, leading to a safe, durable, and cost-effective solution for the building owner or operator.
Analyzing
Roofs with low to moderate damage or good candidates for restoration, but a reroof will be required when roofs are extremely damaged.
With your roof inspection complete, it’s time to determine a path forward. Roofs with low to moderate damage and saturation levels are often good candidates for roof restoration rather than a full recover, and they can be a cost-effective option when the circumstances call for it. Reroofs will be required in more extreme scenarios, with elevated levels of insulation saturation, decking deterioration, and more. As stated before, a good rule of thumb is that any roof that is more than 20 percent saturated is deemed a full tear-off, per many national building codes and standards.
In addition to the level of damage uncovered during inspection, there are some additional considerations that should be made when determining the right repair technique for your project. Some of these include:
What is the anticipated lifespan of the building? Not every structure merits the same level of repair work. A small retail store that sits in the path of a proposed freeway expansion, for example, might not need a repair that ensures 20 years of performance. A major museum in the hub of a cultural district, by contrast, will require a long-term solution. In either case, proven repair solutions are available to best suit the needs of the given situation.
Are there plans to expand the building in the near future? It’s generally more economical to reroof a structure in conjunction with an expansion rather than split the project across multiple years. The need for roof access and impact to building operations can be greatly reduced if both projects can be performed at the same time.
Where and at what time of year will the work be done? A 30-story condo tower in Florida has very different wind, thermal shock, thermal bridging, and UV exposure than a single-story industrial plant in the Midwest. These types of conditions should be considered when developing a repair or replacement plan.
What is the building use and type? Different types of buildings serve various functions and have specific requirements for their roofing systems. For example, a commercial office building may have different needs than a residential home or an industrial facility. Building codes and regulations also vary depending on the building type and use, as well as aesthetic considerations. A hospital and operating room may look completely different from a restoration over the top of a warehouse that houses empty paint cans, for example. And the type and use of the building can influence the budgetary considerations when deciding whether to repair, renovate, recover, or reroof the roofing system.
The Case for Restoration
A 30-story condo tower in Florida would require a different roofing approach than a single-story industrial plant in the Midwest.
Your determination of the right repair method will depend on the specific circumstances of the job at hand. In situations where restoration is appropriate, you’ll find some significant advantages versus reroofing or other alternative repair measures.
Restoration generally requires far less specialized equipment and does not leave the building interior exposed while the job takes place. A good roof restoration process involves removing any debris and cleaning the roof to prepare for the rest of the project. Next, depending on the condition of the roof, a primer is applied to ensure good adhesion for patching, stain blocking, and rust inhibition. Then, patching is performed to make sure all parts of the roof system are watertight. Finally, protective coatings can be applied to ensure long-lasting performance. All the while, regular activity inside the building can continue uninterrupted.
Restoration jobs can also happen far faster than an entire reroof. For contractors, time is money. If you can successfully bring an existing roof back up to its original performance level with restoration methods, you can move on to your next job more quickly. A restoration project can be undertaken with the purchase of just a few high-performance products, a far more cost-effective solution than replacing the roof entirely. Full restorations on average range between $400- to $700-per-square, while tear-off and replacement starts at $1,000-per-square and can go up from there depending on region and project complexity.
For a restoration project to meet its full potential, you can also work with the trusted supplier of high-performance coatings and mastics to help ensure a job well done. Modern mastic formulations are able to deliver outstanding performance that building owners can rely on for the long term. The right supplier may also be able to help you ensure best practices are followed on your next job, leading to more satisfied customers.
Section 3: Common Restoration Practices
With metal roofs, it is important to focus on seams, fasteners, and penetrations during the renovation process.
Adhering to best practices is of utmost importance when undertaking a roof renovation. These practices ensure that the renovation project is executed with precision, quality, and safety, leading to a successful outcome. Following best practices, such as conducting a thorough inspection, testing, selecting appropriate materials, and addressing underlying issues, helps mitigate potential problems and ensures that the renovated roof performs optimally for years to come. Best practices promote compliance with local building codes and regulations, ensuring that the renovation meets the necessary standards.
Metal Roofing Restoration
When it comes to restoring metal roofing, it is important to focus on seams, fasteners, and penetrations. Seams are important to protect against wind-driven rain, and if there is a poor seal or improper install, water intrusion becomes an issue. There are many theories on how to treat horizontal and vertical seams, including taping seams, lifting panels, and sealing underneath or brushing adhesive over the top. Every manufacturer has their own recommendation for both horizontal and vertical seams that should be followed.
During the restoration process look for loose fasteners, which should be removed and replaced with new fasteners. The new fasteners should be one size larger than the original one and attached with a new screw. Once the new fastener is in, apply a layer of mastic over the top of it and a secondary sealant on top of the mastic.
Next, address all penetrations, such as skylights, curbs, roof fence, and plumbing vents. If penetrations show signs of damage, such as rust, corrosion, leaks, or compromised seals, contractors should undertake the necessary repairs or consider replacing the damaged components. This may involve fixing or replacing flashing, gaskets, or seals around the penetrations to ensure watertightness and proper integration with the restored roof system. Contractors should ensure that flashing materials are correctly installed and integrated with the metal roofing system to prevent water infiltration and provide long-term protection.
Contractors may need to apply appropriate sealants or caulking around penetrations as part of the restoration process. This helps reinforce the waterproofing and weatherproofing capabilities of the penetrations and ensures a secure bond between the roofing materials and the penetrations. In general, they should ensure that any repair materials, sealants, or coatings used for penetrations are compatible with the specific metal roofing system and the materials surrounding the penetrations, especially because metal roofs expand and contract.
Single-Ply Restoration
With single-ply, it is important to look at tie-ins where the membrane transitions to other roofing components.
Single-ply roofing is a welded system—either heat or chemically welded—and for this reason, seams must be addressed. Self-adhered tape is one way to restore single-ply roofing, but as always, pay attention to what the manufacturer suggests.
With single-ply restoration it is also important to look at tie-ins where the membrane transitions to other roofing components. Flashing tie-ins, penetration tie-ins, edge tie-ins, roof-to-wall tie-ins, and expansion joint tie-ins are all critical to preventing water intrusion. Look for any issues around curves and the inside or outside corners. Other common problems seen with single-ply membranes include splits and burns, as well as repair issues with base flashings, curbs, and corners. Restoration for single-ply membrane systems typically requires adhesive repair tape or other minor reinforcement approaches.
Single-ply membranes are often exposed to UV radiation. Contractors may select coatings or treatments that enhance UV resistance and protect the membrane from UV degradation and premature aging.
BUR/Modified Bitumen Restoration
When renovating a BUR/mod-bit system, contractors should look for signs of blistering, cracking, or granule loss, which may require repairs or preparation before restoration work can commence. Take note of all penetrations, such as chem curbs, pitch pockets, slash penetrations, and any other vulnerable areas. Pay attention to drains and other waterways, as well as metal edges. Common issues on BUR and mod-bit are located at penetrations and field seams. If it is a gravel BUR system, look for lines of gravel where splits in the system have occurred and repair the splits.
The Four Steps of Restoration (Four Ps)
Once you decide to restore a roofing system, contractors should stick to the Four Ps of Restoration: Prep it, prime it, patch it and protect it. These steps are required for a full restoration system and leaving any one out risks potential failure of the restoration.
Prep
Remove any debris and clean the roof to prepare for the rest of the project. This might entail sweeping, brooming, blowing, pressure washing, taping off areas, and closing off air intakes. This is an important step. Nothing will be successful if this step is not done properly. One of the most common mistakes with roofing restoration is not cleaning or letting the substrate dry. If there is dew on the substrate and a contractor merely blows debris off the surface before priming, moisture could be embedded in the system and cause premature problems.
Prime
Depending on the condition of the roof, a primer is applied to ensure good adhesion for patching, stain blocking and rust inhibition. Primers are most commonly used for stain blocking and adhesion, but with metal roofing systems, rust inhibition primers are important. They help ensure that whatever restoration system is going on top will have a good bond.
In some instances, like with restaurants where grease may be present, a bleed blocking primer can be used to prevent oils from emerging. These primers have solvent in them to keep coatings white.
Patch
Patching is performed to make sure all parts of the roofing are watertight. This is the phase where contractors must pay attention to penetrations, flashing, field seams, and physical damage. Sometimes coatings have been sold as stand-alone water proofers, but that is not the case. Putting a coating over a bad seam without properly preparing it for expansion and contraction will ensure it becomes a bad seam again. Patching should have a mastic base, followed by a coating and embedded polyester, and then a top coat over it. Follow the manufacturer's instructions to apply this patching method.
Protect
The sun produces radiant heat and powerful UV rays that cause thermal shock and rapid deterioration of all roofing materials. This constant exposure results in accelerated aging, lost flexibility, fatigue, splits, cracks and ultimately roof membrane failure. Reflective and protective coatings can be applied to ensure long-lasting performance. All the while, regular activity inside the building can continue uninterrupted. Silicone coating is a good choice for roofing systems that have issues with ponding (though roofs should not be ponding at all). If it is late in the year and you are worried about cool weather, silicone is a good protection option for metal roof restoration.
Silicones and acrylics both have their advantages and disadvantages. Acrylics are more walkable when wet while silicones have a much longer durability and lifespan.
Heat buildup in a roof can also lead to increased building temperatures, building discomfort, unproductive employees and increased energy consumption. Cool roof systems act like a reflective shield to protect the roof membrane. Cool roof systems drastically reduce roof temperatures, thermal shock and heat transfer. In addition, they extend roof life, improve building comfort and substantially reduce cooling costs. And, in the long run, this helps building owners see a much greater return on their investment.
Section 4: Roofing Codes and Tax Incentives
The 2021 International Building Code (IBC) provides requirements for roofing, including materials, installation, and renovation. Roofing renovation typically requires obtaining the necessary permits from the local building department. The IBC doesn’t specify the exact process but provides guidelines for compliance with local regulations.
The IBC provides guidance on structural design and load requirements to ensure safety and performance for renovations. It also includes provisions for weather resistance and water shedding capabilities of roofing materials. These requirements aim to ensure the durability and performance of the roof system. Depending on the building’s type and occupancy, the IBC may specify fire resistance requirements for roofing materials.
The IBC includes provisions related to energy efficiency in buildings, which address insulation, ventilation, and reflective properties of the roof to minimize heat gain or loss.
Specific details and requirements for roofing renovation does depend on the local jurisdiction and the specific circumstances of a project, so contractors should consult the relevant local building code or consult with an expert to ensure compliance with local regulations.
Inflation Reduction Act (IRA) Opportunities
Roof maintenance systems have some tax benefits. They are fully tax deductible for building owners as an operating expense. A key advantage of a restoration system over a new roof system is how they are classified by the IRS. Because restoration is classified as a maintenance item, in most cases it can be expensed in the accounting period it is incurred. On the other hand, a new roof system is a capital asset that must be amortized over a 39-year life.
Recently, architects, engineers and designers have also gained tax benefits. The 179D Tax Deduction, which provides incentives for energy-efficient building design and construction has undergone significant change in 2023. The maximum reduction will increase to $5-per-square-foot (up from $1.80-per-square-foot). To qualify for the higher tier of deductions, buildings must be constructed with prevailing wage and apprenticeship requirements, and must meet or exceed the ASHRAE Reference Standard 90.1 that was in effect for four years prior to the in-service date of the building. Each additional percentage of energy reduction will increase the deduction by $.10, up to $5.00-per-square-foot.
Designers can obtain 179D Deductions from tax-exempt entities, including public organizations such as K-12 schools, higher education institutions, libraries, municipal buildings, public offices, parking garages, and airport terminals. Other tax-exempt entities, such as charitable organizations, religious institutions, private schools and colleges, non-profit hospitals, private museums, tribal governments, and any other organization falling under 501(c), can also take advantage of the 179D Deduction.
The ability to apply reflective coatings to roof renovations and update insulation provides more than doubles the potential for these tax deductions.
Section 5: Conclusion
When it is appropriate, renovation can provide a compelling alternative to traditional roofing methods that is cost-effective, customizable, and minimally disruptive to occupants.
Renovating a roof presents numerous advantages over traditional repair, recovering, or reroofing methods. Its cost-effectiveness, reduced material and labor requirements, and potential for customization make it an appealing choice, and the minimal disruption it causes to occupants adds to its allure as a viable alternative to extensive construction projects. However, it is essential for contractors and building owners to discern when renovation is appropriate and when more extensive measures are necessary. Understanding key indicators and factors that determine the feasibility of renovation is crucial to ensure that roofing systems receive the suitable treatment they require. By recognizing the unique vulnerabilities of different roofing types, contractors can make informed decisions and accurately assess whether renovation is a suitable option for their specific needs.
Erika Fredrickson is a writer/editor focusing on technology, environment, and history. She frequently contributes to continuing education courses and publications through Confluence Communications. http://www.confluencec.com
