Educational Buildings: Safety and Durability by Design  

If you design schools, whether at the primary, secondary, or higher education level, you spend a lot of time looking at durability of materials for the safety of students, educators, and staff. The goal is usually to create a welcoming and inspiring place to learn and grow that is inherently durable to hold up over time. Concurrently, the resulting learning environment needs to use materials that help protect the building and the people inside it. This means incorporating features such as reliable durability, clear signage, and properly operating systems. There is also the recognition that many school and educational spaces fill a need for public gathering and events in their larger communities. Therefore, finding the balance between creating a nurturing and welcoming facility that also meets inherent public assembly safety requirements becomes a distinct design challenge. In this course, we review a variety of specific systems, products, and strategies that allow architects to address all these issues to create exceptional educational building designs for both new and renovation projects.

INTERIOR WALL PROTECTION

Interior walls are at the forefront of the need for durability in schools and educational buildings. Things like wall corners, edges, and other aspects of an interior design are subject to wear and tear from moving people or equipment. Therefore, adding products specifically designed to protect these areas is common and makes sense for many educational situations. The best approach is referred to as targeted wall protection where a specific set of products is used that are designed to absorb impact and protect the underlying portion. By targeting the most vulnerable areas, protection can be added by using corner guard or wall guard products specifically where they are needed. These can include horizontal rails across specific sections of the walls as well as vertically installed corner guards. Since many of these products can be specified with materials that are not only durable but also easy to clean, they help protect the building as well as the people in them.

Taking the concept of wall protection further, sheets of rigid wall covering have been used where large surfaces need to be made more durable and easier to clean. Usually produced in sheets or rolls, rigid vinyl extruded wall cladding comes in several standard thicknesses. For medium duty installations, .028 is used when flexibility is needed such as wrapping a column for example. A slightly heavier .040 can be used to eliminate re-painting where repeated scuffing wears through the top layer of drywall. For heavier duty locations, .060 is used to protect against gouging of the wall, while .080 is used for maximum protection, often installed on top of cement board or fire rated plywood. Most of these products offered in the U.S. are Class A fire rated, with many choices of product types, finishes, and colors to enhance, rather than detract from, an interior design scheme.

For wall areas that need specific types of protection, there are also some specialized choices. These include hygienic wall cladding which is ideally suited for kitchen or laboratory spaces. Coupled with stainless steel corner guards and wall base, this provides a very durable and cleanable surface that is designed to inhibit growth of organic substances. There are also solid surface wall claddings that are nonporous, long-lasting, easily repairable, and available in many different colors. By working with manufacturers of wall cladding and targeted protection systems, the best solutions can be determined for different locations within schools and higher-education facilities.

It is worth noting that if the surface materials used aren’t easily cleaned, that is a problem, since they could become sites of virus or bacteria transfer. On the other hand, if the surfaces can be cleaned, but aren’t durable enough to handle the repeated washing without fading, wearing, or otherwise degrading prematurely, that needs to be addressed as well. Of course, educational buildings are busy places with a lot of people and equipment moving daily. That means the interior finishes can readily get rubbed, bumped, banged, or even abused and can start to show signs of wear quickly. If these interior surfaces become physically damaged, then they can become problem spots that are not only difficult to clean and could be prime locations for germs and bacteria to collect and build up, ready to be transferred to the next person who touches or brushes by them.

Flexible Wall Protection

Protecting wall surfaces from damage while still meeting interior design needs can sometimes be a notable challenge. While rigid plastic protective wall cladding products can offer a particular choice of looks, they may not always match what is being sought for a design scheme. Other choices offer the more varied look of contract wallcovering with some protection characteristics but lack the ultra-durable performance of rigid plastics. This leaves architects and interior designers in a conundrum, especially since certain spaces need the added protection but do not lend themselves to the aesthetic of rigid wall cladding. However, a brand-new class of materials called Flexible Wall Protection is showing great potential to be a true game changer by combining the appealing look of contract wallcovering with the durability of rigid wall protection. As one manufacturer puts it, “Walls can now make an impact while being able to take the impact.”

Flexible wall protection products are durable enough to handle the conditions of harsh environments yet are literally flexible enough to become the showpiece or the backdrop of an interior design scheme. With professional, seamless installation, they can become an uninterrupted finish with an intentional texture pattern to enhance the design. They also fend off stains and vandalism, simply by wiping with standard cleaning agents, although the amount of effort needed to remove the stain or mark will vary based on texture of course.

Flexible wall protection is quite appropriate for educational facilities, particularly since most have some areas that are prone to be constantly bashed and slammed. If this causes damage, particularly in a public space, management will not want to leave it disrepair, so someone on staff is usually assigned to repair these problem areas–repeatedly. There’s a subtler form of damage, however, that often accumulates slowly but eventually leads to a shoddy appearance, namely scuffs and abrasions. For example, backpacks rubbing along a school corridor wall may not be enough to damage drywall, but creates enough contact to leave marks, scuffs, and rubs. When this happens dozens, if not hundreds, of times a month, the walls soon start looking quite different from the design intent. Flexible wall protection can provide a solution to this problem by remaining intact, masking any damage to drywall behind it, removing the urgency of a repair, and containing any gypsum dust from being released into the building. In all, it is a preferred surface protection solution for many interior wall surfaces compared to vinyl wall covering or rigid finish options.

Printed Interior Wall Surfaces

Wall surfaces in schools and higher education facilities are commonly used to convey information using artwork, graphics, or similar means. Just like any other wall surface, however, the images need to hold up against heavy use, or even abuse, plus be easy to keep clean. To meet these needs, many architects are turning to innovative wall protection systems that also offer large-scale images that can promote school spirit and morale or spread inspiration for learning.

Printed wall protection systems are commonly made using clear, rigid, sheet plastic with crisp digital imagery printed on the reverse side. This creates greater durability since the rigid sheet protects the image from scratches, dirt, and other hazards, including impacts from backpacks, utility carts, etc. The clear sheet also allows the surface to be cleaned regularly without affecting the graphic image.

From a design standpoint, the possibilities are virtually unlimited in terms of the colors and images that can be printed. Logos, mascots, school mottos, beautiful artwork, or any other type of vibrant imagery is possible. Ultimately, the beauty of these systems is that they help create a design feature that doubles as wall protection that is easy to clean and durable.

The durability and suitability of such rigid wall protection with applied graphics can be ensured by specifying products that meet recognized standards. Specifically, at a minimum, they should provide a Class A fire rating and meet ASTM F 476-84 “System Impact Resistance” and ASTM D 4060 “Taber Abrasion Resistance.” For locations that are subject to harsh conditions or where sanitation is a particular concern, they should also meet ASTM D-543 “Chemical and Stain Resistance” and ASTM G-21 & G-22 “Fungal and Bacterial Resistance.”

ELEVATOR CAB INTERIORS

Among the most used interior spaces in multistory educational building are the elevator cabs. Over time, elevator interiors can get damaged, especially if the cab is used for both passengers and other purposes, like moving furniture, equipment, etc. Even with the best-padded intentions, furniture movers and delivery drivers can ding up, gouge, and scuff walls with dollies, carts, and crates. Hence, it is quite appropriate to consider protecting elevator cabs as much as other wall and similar surfaces.

Educational building owners often spend significant amounts of money on major elevator renovations. If that only includes elevator equipment upgrades, riders will not notice anything new and will still feel like they are in an “old” elevator. Money spent on things like replacing the jack, power unit, controller, and door operator aren’t visible to the public users. Hence, when thinking about elevator renovation, it is worth considering both mechanical and interior upgrades.

Some of the main reasons to renovate the cab interior are to update the appearance and make it more appealing by giving it a refreshed look. There may also be an interest in making the cabs more energy efficient with LED lighting or adding extra protection to the cab walls. Another reason to enhance the cab appearance is that some people are terrified of elevators and suffer serious anxiety when riding in one. Interior upgrades can help ease those few minutes they spend riding the elevator by providing a more comfortable and appealing experience. Additionally, graphics can be added to help promote school spirit or a sense of place.

The most cost-effective and innovative way to carry out such an elevator cab upgrade is to use preconfigured elevator cab renovation systems from a manufacturer that has a specialty line of products to address these needs. This system can include any or all the following elements.

• New Panels: The elevator panels that line the walls are what primarily make up the appearance of the cab. These panels also typically take quite a beating─from carts, construction equipment, vandalism, and whatever else may come its way. Fortunately, the panels can be made of durable and rugged materials that can be made to look like any range of materials from wood to metal to stone or custom choices.
• New Ceilings and Lighting: Elevator ceilings come in many different styles and can be selected to suit an overall design concept. Lighting in elevator cabs can be chosen from among common lamping options such as halogen, incandescent, fluorescent, or energy efficient LED. Keep in mind that people tend to be more comfortable in a well-lit interior, so combining a brighter ceiling with increased lighting output can help people feel more relaxed inside not to mention creating a newer and cleaner look. The energy efficiency of elevator cab lighting is notable since these lights typically stay lit 24 hours a day, 7 days a week, meaning they are running for 8,760 hours a year. Further, selecting energy efficient LED lighting means the lamps have a much longer service life notably reducing maintenance costs for replacements.
• New Handrails: Handrails in elevators get attention for ADA or accessibility code requirements, but they also provide stability for users (i.e., something to grasp) while the elevator stops and starts. This is particularly helpful for elderly, disabled, or injured people who need help to reduce the risk of a fall. Beyond the people aspect of handrails, they provide a means for a complete look to the cab and can act as a wall guard, too. By providing a stand-off surface from the wall of the cab, handrails can reduce the chance of equipment or furniture striking the wall panels. As part of a total system for elevator cabs, handrails come in different shapes, sizes, and finishes.

Paying attention to both the appearance and durability of elevator cabs clearly pays off in terms of creating successful, innovative interiors and better experiences for all users.

COMMERCIAL WINDOW TREATMENTS

Adding natural daylight to an educational building is fundamentally a good thing for many reasons, not the least of which is the documented cases of increased student performance and well-being that come about from it. However, the penetration of that daylight and/or direct sunlight into a school needs to be controlled. Too much concentrated daylight can create uncomfortable glare or interfere with computer and audio-visual images. Further, depending on the compass orientation of the building or the time of day, the sunlight could add more solar heat gain than desired, creating spaces that are uncomfortably warm. For all these reasons, providing a solution for controlling or directing daylight into interior spaces is important for a successful outcome.

Solutions to these window issues have been used on both the exterior and interior of buildings. However, controlling daylight and glare from the inside is often a functional necessity in many cases for educational buildings. Teachers and staff need to be able to quickly and easily make adjustments to suit periodic or daily changes in classroom needs for presentations and activities, or simply to reduce distractions. In response, manually operated roller shades have commonly been placed in schoolroom windows to create flexibility and control. Fully open, they can allow for full penetration of daylight and clear views to the outside for students. For times when solar control is needed to reduce light, glare, or heat gain, they can be closed fully or partly. While historically, the shades have been simply room darkening, opaque material, there are now a myriad of other options available to suit differing needs that improve the quality of the indoor school environment.

Among the options, textured roller shades can be used which allow diffused daylight to pass through a fabric appearance that reduces the total light transmission. In this way, they reduce glare, add comfort, and produce a favorable light quality inside the building. At the same time, they provide a degree of privacy or muted views through to the outdoors as may be desired. The particular characteristics of any such shade can be customized based on the particular weave and percentage of the area that is open versus closed in the fabric. Textured, partial light transmitting shades can be used alone or in combination with other shades that are fully opaque to provide the greatest degree of flexibility and control.

Shade systems are available that use chains or cords to raise and lower the shades, but there are also products available that are completely cordless. Such cordless window shades are a logical choice for school buildings since the presence of dangling cords can be a safety hazard for children. Rather than trying to contain or conceal the cords, the elimination of them dispels any potential problem, thus meeting new consumer product safety standards and eliminating the need for a ligature. This makes them safer for students of all ages from the risk of strangulation from cords. Cordless shades commonly use a spring roller system that allows for direct and easy manual adjustment of the shade with capability to raise and lower it to any height. A privacy track can also be included along the sides to keep the shades in place and provide additional light-blocking at the window edges.

In some higher security or specialized school settings, where damage or tampering is a particular concern, it is worth noting that there are self-contained cordless window shade systems specifically designed to resist such damage. This type of system features side channels and an extremely durable security box fascia to protect its mechanical components, making it tough to inflict damage. The shade material itself can also be specified from available, non-organic, resilient fabrics that are durable and easy to clean.

ARCHITECTURAL SIGNAGE

Educational buildings tend to be large, with many different rooms, and they are often designed to accommodate a large number of people with different roles, including students, teachers, staff, and vendors. As such, navigating through the building and finding the right room is most typically facilitated using architectural signage. Some signs are useful and desirable for general purposes, but others are required to comply with accessibility requirements, including ADA, to address inclusivity. In addition, safety is a consideration with signage since all building occupants need to be clear on where to go and how to identify designated places in the event of any emergency.

Creating a consistent architectural signage package that meets budgetary needs is often achieved by using standardized signage products that can be readily and easily customized as needed with wording or graphic content. Manufacturers of such signage products commonly have a range of choices for standard sizes, colors, materials, and finishes. They are also usually very up-to-date on understanding the latest requirements for accessibility, such as readable contrast, braille, mounting heights, sign locations, etc. They can also be quite helpful in working with an interior design scheme to allow the signage to be readily recognizable while conforming to an overall design intent for the spaces where they are mounted. Designs can accommodate artwork, biophilic, or organic elements, and even custom graphics.

It is important to remember that the information contained on signs can be fully customized when using manufactured signage. Graphics or wording can be provided that is then transferred to the appropriate sign. Design professionals can work with the manufacturers directly to select the preferred looks, colors, size, and shape of the signage to achieve the best intended results. This can include selecting different accent pieces behind the actual signage portion to blend or contrast with the surrounding walls or doors. It can also mean having different specific sizes or shapes for different purposes. For example, room identification signs can follow one design scheme while general information signs or safety related signs can follow a different design scheme. Overall, the end result is a functional, easy-to-read system of architectural signage that is coordinated and code compliant.

In terms of installation of signs, many manufactured sign systems have developed effective and visually appealing ways of attaching signage. Those that are easy to install help with the construction or renovation of a facility, but that trait also makes it easier for maintenance and facility managers to remove, relocate, or replace signage when it is needed. In fact, there are signage products available that can be used with inserts or magnets for quick changeability. Similarly, using a manufacturer with a long-standing track record in the business of architectural signage means that they will likely be available for future architectural signage needs if the building operation requires some new or different signs to match the ones originally installed in a project. question6}

EXPANSION JOINTS

There is another area that presents itself on most large educational buildings which deserves some special attention. Specifically, we turn now to architectural expansion joints, which are predetermined gaps in large structures that are designed to absorb environmental movement in buildings. In large educational buildings, they are a necessity, particularly where buildings are segmented into different sections, or if one structure attaches to another structure, such as a parking garage or other use. The location, size, and movement requirements for all such expansion joints are project-specific and appropriately established by the Structural Engineer of Record.

The design width of an expansion joint at an average air temperature is referred to as the nominal joint size. The first step is to acknowledge the nominal joint size for a particular building and the range of movement between the fully contracted size and the fully expanded size. The building movement that makes expansion joints necessary occurs due to several common reasons with three types of movement that typically need to be accommodated:

• Thermal Forces: This type of movement is most typical and caused by daily environmental temperature changes in and around the structure. Thermal movement is primarily “one-directional” in nature and is the result of the expansion and contraction of structural elements as affected by heat, cold, and humidity levels. The typical amount of thermal movement is approximately 10-25 percent of the nominal joint size. That means the minimum contracted size (i.e., during cold temperatures) should be 10- 25 percent more than the nominal joint size and the maximum expanded size (during warm temperatures) should be 10-25 percent less than the nominal joint size. If expansion joints aren’t put in, then thermal expansion and contraction can cause buckling of structural surfaces in places like roofs and interior floors.
• Seismic Activity: The shifting of the earth’s tectonic plates (i.e., earthquakes, tremors, etc.) and shifts along fault lines are the source of seismic activity. Seismic movement may be horizontal, vertical, in shear, or a combination of all three. Seismic expansion joint widths may need to increase with higher floor levels to accommodate the additional, cumulative movement that needs to be addressed. These joints must have the capacity for movement of plus or minus 50-100 percent of the nominal joint size associated with them. When it comes to expansion joint systems, it is important to select systems that can “reset” themselves after a minor seismic event and allow workers to reposition panels easily.
• Wind: loads Movement induced by high winds, can force the structure to sway. This movement is normally perpendicular and/or parallel to the joint. This is common where a low horizontal building span meets with a taller vertical element. Movement in these joints is typically on the order of 50 percent. Over time, the near-constant effects of wind pressure on the sides of buildings can lead to serious issues, such as aerodynamic instability, torsion or swaying, erosion of certain building materials, and cladding failure due to wind load or impact of debris. In extreme cases, it can lead to structural failure and damage to people and property. Therefore, when designing a structure, it must be able to both withstand high wind loads, but also work with them. As with seismic activity, expansion joint systems should be able to “flex” and yet remain in place as the building sways or torques.

By properly addressing all these conditions, the building can be protected from movement that will invariably occur and avoid the resulting damage that is possible.

Typically, the joints need to run continuously through all adjacent planes to fully separate building sections and allow independent movement. That means that any given project scope could include interior joints, exterior joints, or both, in things like walls, roofs, floors, building veneers, soffits, parking decks, patios, roofing systems, etc.

Commercial Washroom Systems, ADA Compliant

One of the most used parts of your school are the bathrooms. The level of resiliency and cleaning product durability that can withstand commercial bathroom or washroom environment needs to be high. At the same time, education systems must consider not only the durability of these spaces, but also ADA compliancy. When it comes to shared dormitory washrooms, we see a few common problems: wall panel cracking, waterproofing membranes, and showers that are not ADA-compliant.

Be sure to call out silicone joints as needed to ensure panels can expand and contract with the structure. Typically, these can be placed at inside corners, but may need to be done between in-line panels depending on anticipated temperature fluctuation in the room. Well-written installation instructions should call out how often these are required

Waterproofing membranes in showers and bathrooms have been an industry standard for decades. But the challenge is making sure drainage holes cut into the membrane perfectly align with the stub up and tie into the drain hardware securely to prevent leaks. However, membranes are not needed with Inpro shower bases, but can be used if the membrane is compatible with silicone per membrane manufacturer’s recommendations. Modifications may also be made to the cast base drain opening to allow for a drain assembly that can accommodate a membrane. This added layer may disrupt sizing and will need to be accounted for on a job-to-job basis. There is the potential to save time on the jobsite and shave dollars off the budget by omitting membranes, when possible, when a manufacturing offers a non-porous solid surface designed to be water-tight when the proper sealants are used.

When it comes to ADA compliancy, templates are a great option for showers. use them for precise Transfer or Alternate Roll-in showers to ensure the studs are adequately spaced to ensure 36" (914mm) inside dimensions. When possible, take advantage of ADA minimums – such as 60" wide Alternate and Roll-in showers; 30" (762mm) depth for Roll-ins; and 36" (914mm) opening for Alternate Roll-ins. In other words, they are minimums, and by stretching the dimension a bit vs. calling out exact dimensions you can account for construction and manufacturing tolerances. Oversizing by even .25" (6.4mm) can be very helpful. Remember that the transition from floor to base must not exceed .5" (13 mm). It is critical to understand the height of the product specified and the recess or float needed to facilitate an ADA- compliant washroom. For example, a rear trench drain may be over 2x as thick at the front edge vs. a front trench drain design.

Working with a manufacturing that is well versed in commercial washroom systems can help you avoid common mistakes, and ensure your washrooms meet codes and standards that exceed expectations.

EXPANSION JOINT SYSTEMS

Once the engineer has determined the locations and recognizing that an open joint in a building needs to be addressed, it is then typically up to the architect to select the means to cover or seal that joint. Any expansion joint filler or cover system needs to accommodate the full anticipated range of movement. When properly designed and constructed, they can be integrated with their surrounding construction such that they blend in with a design and almost disappear. Common ways to do that depend on the size of the joint. Caulking or sealant may be all that’s necessary for very narrow joints, but wider joints need a coordinated system. Compressible fillers are common and made from different types of foam that is secured into the joint. Others use bellows or blankets to fill the gap that can bend and move with the adjacent building structure. Architectural joint cover systems are also common and can be selected based on their ability to absorb building movement, support a given load, maintain safe egress where applicable, and be compatible with adjacent surface finishes.

In light of all of the above, we take a closer look at some different types of expansion joint systems in the following sections.

Fire-Resistive Joint Systems

In many cases, expansion joints are installed in construction that needs to maintain a fire-resistive rating. This is problematic since building expansion joints in floors, roofs, or walls create a pathway for fire and smoke to travel through. Of particular concern is the need for expansion joints in dormitory buildings at boarding schools or on college campuses, where fire isolation and containment is mandated by codes for occupant safety. The way to address such fire concerns is to use expansion joint fire-barrier products or systems that can provide protection for 2, 3, or 4-hour rated conditions as warranted. That means the joint products or systems need to be fire-resistance-rated in accordance with normal test and fire rating standards. When installed, the intent is to provide a continuous, uninterrupted fire barrier in the structure and the joints─all of which is critical for life safety. Recognizing this safety issue, an expansion joint system can be selected to fit the specific needs of a project and provide the level of protection required to keep the threat of fire contained.

There are two fundamental types of fire-rated joint systems. The first is to use compressible foam products that have been shown to achieve appropriate fire ratings. In some cases, the foam can be totally impregnated with fire retardant as an integral part of a manufactured product. This is the best solution and type of fire-resistive product to specify. A fire-rated pre-compressed foam material that is totally impregnated with fire retardant will maintain the specified and tested fire-rated assembly even if the facing has been damaged. Alternatively, a field application of an intumescent coating or silicone can be applied on the face of the foam joint. This method is, indeed, cheaper for the manufacturer. However, seals that rely on their silicone or intumescent face coating will no longer achieve their UL-2079 assembly rating if either of these faces are damaged or vandalized.

Another fire-resistive product is based on the use of fire blankets. These are the most versatile system, suitable for expansion joint gaps of 2-32 inches and able to withstand high rates of movement. Fire blanket systems come in two forms—either ceramic cloths with intumescent layering or graphite sheet goods encasing insulating blankets. In seismic conditions, they allow for approximately 50 percent of joint compression and expansion movement. Some models are able to retain their rating throughout lateral shear movement testing while others cannot. Fire blankets are tested in concrete, but alternate substrate conditions may also be acceptable.

Note that fire blankets can be specified either to withstand water or not. Those that cannot withstand water exposure and become wet are often rendered useless against smoke, fire, and heat; even after redrying, they carry diminished fire resistance. Products that are rated and tested for water exposure during or after construction, or for open structures such as parking facilities and stadiums, provide fire protection even if they become wet. It is important, therefore, to select and specify the appropriate material for the water conditions anticipated in the building.

Foam Seals

In certain applications, the use of foam seals in expansion joints provides a solid seal against the elements and moisture protection. Foams can also provide acoustic and insulation properties. As a general rule of thumb, limiting foam seals to applications with a joint width of no more than 8 inches (200mm) or smaller is good practice. Use of foams for expansion joints larger than 8 inches leads to two things: 1) exceeding the foam’s performance characteristics, including possible sagging of the foam seals in vertical applications due the weight of wider sizes; 2) exponentially higher costs compared to other expansion joint cover solutions.

Fire-rated foam seals are also available and suitable for 6-inch and smaller gaps and conditions where abuse is not likely. These systems are comprised of open-cell polyurethane foam impregnated with a fire-retardant material. These foams can be faced with colored silicone to match a desired décor or design aesthetic. Fire-rated foams are usually lab tested in concrete and cement-board wall conditions (not drywall).

When selecting an appropriately sized foam, there are two fundamental types to consider: open-cell or closed-cell foam seals. Open-cell foams provide some breathability and allow for flow-through of water and vapor, making them best suited for vertical applications. Like many exterior veneer systems, if moisture becomes trapped in a wall cavity, building systems allow the moisture to wick out. This is a good quality and a major focus to eliminate potential mold issues in vertical applications.

By comparison, closed cell foams are absolutely watertight and do not allow moisture or bulk water to enter the body of the foam. They are best suited to horizontal applications where moisture could remain trapped and water penetration cannot be allowed. Closed cell can also be utilized on below-grade vertical applications as support and closure to positive-side waterproofing at expansion joints. These are tougher to compress but can be placed under tension (or expand) well.

Compression Seal Systems

As their name implies, compression seal joint systems are installed into a joint, absorbing movement and flexing through compression of the seal. This type is an excellent option for exterior application where waterproofing is required. These seals are best employed for heavy pedestrian and moderate vehicle loading such as plazas, decks, parking garages, etc. Nominal joint sizes for these systems should be in the 1-to-4-inch maximum range. Compression seal systems come in a few common forms: vehicular “winged” seals or the more moderate epoxied standard seals. Proper use of two-part epoxies ensures solid adhesion to the deck, and heat-welded seams ensure watertight performance. Building aesthetics can be enhanced using colored compression seals.

Roof Bellows Systems

Expansion joints that pass along a roof membrane need particular attention to remain watertight. Such systems use either a TPO or PVC membrane that is bowed up like a bellows so that it flexes to accommodate seismic or thermal movement. As with counterflashing, the seal must run under the metal flanges of the bellows system to allow water to be shed away from the joint opening. Also, a compatible, nonreacting mastic should be used to ensure watertight adhesion of the seal.

Beyond the typical horizontal aspect of a roof bellows expansion joint system, the transition to walls, parapets, edges, or other building components is critical. Tying in horizontal and vertical joint systems requires transition covers to help maintain watertightness. Architectural drawings and details should always cover this, but the reality is that sometimes transition covers and tie-ins are missed. This can cause significant problems in the watertightness of the roof and adjacent areas.

Metal Cover Plate Systems

In many cases, exposed foam or compressible seals will work just fine and provide suitable aesthetics for the particular area of the building in which they are installed. Often, however, there are cases where a metal system is called for in order to achieve the strength and durability needed. Metal cover plate systems should always be used for joints 6 inches or wider in open structures. Wider joints have surfaces that are exposed to direct loads imposed by tires. A system with shallow, thick, heavy-duty frames offers a high degree of strength in its profile for longevity against the constant vibrations imposed on the cover plates each time vehicle travels over it. Other attributes to look for include noise dampening and water resistance.

There are two basic types of expansion joint cover solutions in general–surface or recessed mounts. Surface mounted systems typically are very cost effective but have wider metal sections that are visible. They are simple to install and are great for remodels and additions or projects with particularly tight budgets. Products that are recessed into the deck are flush with the finished flooring and receive no jarring impacts from rolling loads. They also typically have far greater visual appeal since they can be specified with a recessed pan in the middle that can receive a finish material to match the adjacent materials (i.e., flooring, wall material, ceiling, etc.) In this way, the aesthetics of the space are not disrupted by looking at aluminum plates, however they do require greater trade coordination and are more costly. Nonetheless, they may be the best choice, particularly for interior or exterior systems that are subjected to a lot of pedestrian or light vehicular traffic as noted earlier.

CONCLUSION

Educational buildings serve large numbers of people with different needs. That use makes them inherently subject to conditions that require greater durability, safety, and performance. Addressing specific design items such as wall protection, elevator cabs, window coverings, architectural signage, and expansion joints helps achieve overall building designs that can best protect the building and the people that use them.

Peter J. Arsenault, FAIA, NCARB, LEED AP is a nationally known architect and a prolific author advancing positive acoustical experiences through better building design. www.pjaarch.com, www.linkedin.com/in/pjaarch