Continuous Insulation Systems for Exterior Walls

High performance through sprayed-in-place foam insulation

Peter J. Arsenault, FAIA, NCARB, LEED AP

Techniques for insulating exterior walls in commercial buildings have received considerable attention in recent years for many good reasons. Energy codes are requiring higher thermal performance values in walls. Green building standards and energy efficiency programs seek to exceed the minimums called for in the codes. Building owners are seeking to control energy consumption and associated expenses while still controlling construction costs. All of this has architects and other building professionals seeking solutions for proven and effective exterior wall assemblies that provide the thermal performance needed. Among the emergent and popular choices, spray foam insulation is being used to address a number of thermal performance needs in different types of wall assemblies.

Spray Foam Insulation Overview

When selecting building insulation, architects have a broad range of products to choose from. Foam insulation products, whether used in board products or sprayed in place, have typically and rather consistently been shown to provide equal or greater insulation performance per inch than other products such as batt or loose fill insulation. While foam board products are common and widely used in wall and roof assemblies, foam that is sprayed in place in the field is becoming more widespread for a variety of performance and construction ease reasons. In particular, wall assemblies in commercial buildings that use spray foam insulation have evolved to be a very attractive and pervasive technology with greater flexibility in regard to both design and installation.

Right up front, it should be noted that unlike traditional insulation products, spray foam insulation is mixed and formed in the field. Most of these systems require two distinct ingredients that are combined on site using specific equipment associated with a manufactured foam product. Typically, equipment is mounted in a trailer or truck with flexible hoses carrying the needed ingredients from there to a handheld gun that both mixes and sprays the combined product onto the surfaces being insulated. As soon as the two parts are mixed, a chemical reaction begins causing the liquid mixture to foam, expand, and eventually harden. This customized on-site application means that the sprayed insulation readily conforms to the shape and geometry of the surfaces it is being applied to while its chemical make-up provides the needed properties for it to adhere to those surfaces.

Continuous spray foam insulation is suitable for use in commercial buildings to create superior thermal performance, air sealing, and moisture control. Photo courtesy of ICYNENE, Inc.

Because of this full custom on-site application, spray foam insulation is generally found to be effective at boosting the energy performance of wall assemblies in multiple ways. First, it fills completely the spaces being insulated. In typical stud wall cavities, that means that irregularities from framing can be filled around rather than restricting or compromising the amount of insulation installed. This complete filling is thus unhindered by unusual conditions that can be a significant challenge for other insulation products that are pre-cut or pre-formed in shapes that differ from field conditions. Second, spray foam has been shown to hold its shape over time such that sagging, settling, and other potential incomplete insulation installations that cause gaps or voids can be readily overcome with spray foam insulation. Third, it significantly reduces air leakage, thus reducing unwanted air infiltration. In fact, spray foam insulation has been used in many buildings specifically to seal openings, penetrations, and around doors and windows. Because of this air sealing quality, it can also be an effective barrier that minimizes airborne moisture transfer. Keeping unwanted moisture out of wall assemblies has long been a goal of successful design, thus these properties are significant indeed. Overall, the use of spray foam insulation, then, goes beyond just R-values and truly addresses a comprehensive way to optimize energy efficiency.

Within the industry, there are two common types of spray foam insulation that are in use today. We will look at each one in detail.

Low-Density Open Cell Insulation

With a common density of about 1/2 pound per cubic foot, open cell spray foam insulation is relatively light in weight and comes with an R-value of approximately 3.5 to 3.7 per inch. It is suitable for use in cavity wall installations covered by sheathing on both sides.

Spray foam insulation is mixed on site and applied using spray gun equipment appropriate to a particular manufacturer. Photos courtesy of ICYNENE, Inc.

Low-density open cell spray foam has a comparatively softer make-up which means that it will effectively air seal around the edges and perimeter of stud cavities and any penetrations. It also means that it can flex and adjust to continue to provide an effective air seal even as the building may settle, expand, or contract. However, while open cell insulation is an effective air sealant, it does allow water vapor to permeate through it. Hence, in cold climates a warm side vapor retarder (e.g., vapor retardant paint) will be needed to control vapor diffusion in an exterior wall assembly. Some approved vapor retarders can be painted directly onto the insulation. There is, however, a wider range of vapor retarder coatings available for painting on the sheathing or gypsum board which the open cell insulation is applied against. And in cases where the wall assembly is exposed to water penetration, open cell insulation may reject bulk water depending on the specific brand. This point should be verified with the specific product manufacturer since this trait varies between products.

Some of the other benefits of open cell insulation are tied to its lighter, softer, and more flexible make-up. Acoustic control, for example, is enhanced in wall assemblies due to its absorptive properties, more so than with rigid insulation. Should water infiltrate the assembly for any reason, its vapor permeability means that the material can dry both toward the interior and the exterior as may be preferred. As a material it does not provide a food source for mold meaning it won't grow in the insulation in a wall assembly. Finally, the cost of open cell spray foam insulation is generally very attractive and competitive when compared to labor and materials for other types of insulations.

Low-density open cell spray foam insulation has been installed to fill and seal stud cavities of this prefabricated wall panel and shipped to the site for final installation. Photo courtesy of ICYNENE, Inc.

Medium-Density Closed Cell Insulation

As the name implies, medium-density spray foam insulation is heavier than low-density spray foam, coming in at about 2 pounds per cubic foot, or roughly four times heavier than low-density material. Its other defining characteristic is the closed cell nature of the insulation when mixed. Since it becomes a series of small bubbles (cells) of trapped insulating gas (a blowing agent), the thermal performance is directly enhanced, resulting in an over 70 percent increase in R-value compared to open cell insulation. R-values are possible up to R-6.9 per inch for closed cell spray foam compared to 3.7 per inch for open cell. The closed cell make-up of this insulation also means that it serves as a full air barrier eliminating the need for a separate product to perform that function. In fact, according to the Air Barrier Association of America (ABAA), many medium-density spray foam insulation are classified as air barrier materials and are the key component in tested air barrier assemblies. And in terms of vapor permeance it tests as a class II vapor retarder meaning it has very low permeance, much more so than open cell low-density spray foam.

Medium-density closed cell insulation can be spray applied to the outside of the sheathing on a stud cavity wall assembly and remain durable and water resistant during the construction period. Photo courtesy of ICYNENE, Inc.

Because of the variety of desirable physical properties in medium-density closed cell insulation, it is suitable for a variety of locations in wall assemblies. When used in stud wall cavities, it will provide higher R-values, excellent air sealing, and add some rigidity to the framing by virtue of its denser make-up. And because it already qualifies as a vapor retarder, no additional paint, membrane, or other material is needed beyond this insulation. Closed cell spray foam insulation is also rigid and durable enough to be installed outside of a stud cavity such as between masonry wythes or behind a masonry veneer. This means that the insulation can be spray applied continuously without interruptions by studs or other building components. This is quite significant since energy codes and standards such as ASHRAE 90.1 have recognized the performance boost achieved from continuous insulation (ci) in wall assemblies.

In terms of wall and façade design, closed cell insulation has the benefit of achieving higher R-values in thinner wall assemblies. From a construction standpoint, the combination of thermal, air barrier, and vapor retarding characteristics means that one product provides all three of these functions. That helps control material and labor costs. High-density foam also provides a stronger, more impact-resistant, rigid insulation material in cases where those are desired characteristics. Because of its cell structure it is water resistant and is approved by FEMA as a flood-resistant material. And, like open cell insulation, closed cell insulation is not a food source for mold to grow on the foam, even in the presence of water or vapor.

Spray Foam Insulation Design Considerations

Regardless of the choice of the type of spray foam insulation being used, there are several general considerations to take into account when deciding how best to incorporate it into a building design including the following:

Fire Resistance and NFPA Testing of Assemblies

Building codes address foam insulation directly and typically require that it is covered or separated from the interior of the building by a 15-minute thermal barrier such as gypsum board or other approved material. When used in an exterior wall assembly, the concern becomes the control or prevention of fire within the wall assembly itself or between floors within that assembly. To receive appropriate fire code approvals, the entire assembly needs to be tested and evaluated, not just the component materials. Hence for a project being built according to the International Building Code an exterior wall assembly with spray foam insulation typically requires testing in accordance with ASTM E119 (timed fire resistance rating of assemblies) or NFPA 285 (evaluation of combustible components in a non-combustible assembly) standards in order to meet the safety and fire code demands of most jurisdictions. At a minimum, compliance with NFPA 285 is needed for most wall assemblies. Note that the details of NFPA 285- and ASTM E119-compliant wall assemblies vary according to the spray foam manufacturer and extra fireproofing attention may be necessary for some designs, particularly when detailing openings around windows and doors.

Environmental Considerations

Spray foam insulations require blowing agents to work and some of those agents are better for the environment than others. Materials used as blowing agents can be rated based on their Global Warming Potential (GWP) by comparing it to other materials. The most basic greenhouse gas is carbon dioxide with a GWP rating of 1. Hence, a spray foam insulation that is specified which uses only water and carbon dioxide as the blowing agents will similarly have a GWP rating of 1. Currently, there are several low-density spray foams with this very low environmental impact rating and at least one medium-density spray foam product has it as well. By contrast, all rigid foam insulation and most medium-density closed cell spray foam insulation need to rely on other blowing agents beside water and carbon dioxide to produce the desired results. Depending on the blowing agent used, the GWP rating can be very high up to around 1,430 due to its hydro-fluorocarbon (HFC) make-up. That means that the insulation has a greenhouse gas within it that is 1,430 times more potent than carbon dioxide. Of course there is only an environmental impact if it actually gets released from the insulation and into the air, which may not happen during installation. Nonetheless, if using closed cell spray foam insulation, it becomes important to seek out and specify a product with the lowest possible HFC content and the lowest possible GWP.

Traditional fibrous batt insulation is prone to incomplete filling of the stud space cavities, allowing greater heat transfer than desired. Image courtesy of ICYNENE, Inc.

Construction Considerations

The nature of any field-applied building product is such that the quality and the effectiveness of the final installation are directly dependent on the experience and qualifications of the installer. Variable field conditions such as air temperature and the condition of the substrates being sprayed upon can directly impact the final results. An installer that understands and adjusts to those field conditions can make all the difference between an excellent installation and one that could be compromised. Further, the nature of spraying the insulation is such that there will likely be some overspray or airborne spray that needs to be contained. Properly protecting the surrounding surfaces and coordinating with the work of other trades to be sure that mishaps are avoided can be very important aspects to the installation. With all of this in mind, it is worth a little investigation ahead of time to be sure that the spray foam insulation being specified has qualified and reputable installers are available to do the work in the building location.

With a basic understanding of the attributes, characteristics, and product variables of spray foam insulation, let's turn our attention to its critical function—energy performance.

Thermal Resistance with Spray Foam Insulation

There are two fundamental ways to use spray foam insulation in exterior wall assemblies—as a way to insulate in stud cavities and as a way to provide exterior continuous insulation.

Stud Cavity Insulation

The primary method of insulating a stud wall system whether framed in wood or metal has not changed notably over the past 40 years. The traditional approach has been for batt type insulation to be placed between the framing members. In this approach, the insulation is routinely compromised due to compression by mechanical, plumbing, or electrical components embedded within the same stud cavity. Also not to be overlooked is the sag potential of many batt insulation products which can result in loose fits that don't end up completely filling the stud cavities over time, resulting in less than stated thermal performance.

Spray foam insulation overcomes many of these thermal performance issues in stud cavities. Low-density open cell insulation is most commonly used for this application since its physical characteristics are well suited to form to the conditions of the cavities and the cost is economical. By field applying it against the interior face of exposed sheathing, it can fill the cavity space completely, thus assuring the full thermal value of the wall is realized. If all of the mechanical and electrical work is roughed into the wall, then the insulation can appropriately fill around all of those irregularities as well creating a thorough installation. The end result is an insulated wall with a much more effective full R-value from the spray foam than a potentially compromised R-value for batt type insulation.

It should be noted that while stud cavity insulation systems have the benefit of economizing on wall thickness, they do not provide continuous insulation across the wall due to the recurring thermal bridges associated with the studs. Energy codes and green building standards have recently recognized that exterior walls with insulation installed between studs, particularly steel studs, have real performance limitations due to these thermal bridges. Most take into account the overall calculated U-factor of the total assembly and do one of two things. Either they set the required R-values of a typical assembly higher to take into account the lower performance due to thermal bridging, or they require that a maximum U-factor of the total assembly be achieved.

ASHRAE 90.1 which is appended to many energy codes and standards includes some very clear correction factors for this calculation. For example, a metal stud wall using 6-inch nominal studs at 16-inch o.c. may include insulation that carries a manufacturer's rating of approximately R-3.5 per inch for a total of approximately R-21. However, the frequency of the metal studs including the head and track pieces create a typical stud wall area that is on the order of 20 percent stud and track faces and only 80 percent solid insulation. This ratio compromises the overall effective wall R-value by as much as 65 percent. Therefore AHSRAE 90.1 assigns a total working value for this typical assembly of only R-7.4 (U-factor of 0.135) which is little more than a third of the insulation R-value.

At this level it does not meet the minimum energy performance levels required to be code compliant in most of the U.S. Therefore, in order to properly address the thermal bridging at each of the studs which reduces overall wall performance, an additional approach is needed as discussed below.

Exterior Continuous Insulation

A second approach of insulating wall assemblies is to use a continuous insulation layer installed on the outside of the stud wall framing and sheathing. It is this continuous insulation layer that is recognized in the code and U-factor calculations that makes up for and stops the heat transfer occurring at each stud. By insulating over the outside of the stud wall, the temperature difference across the studs is less thus reducing the rate of heat transfer. Further, the additional insulation adds to the overall thermal performance of the wall assembly quite dramatically since every inch installed is fully effective without any inherent thermal bridging or other compromises.

Using a combination of low-density open cell spray foam insulation between steel studs and a continuous layer of medium-density closed cell spray foam insulation outside of the sheathing creates an exterior wall with superior thermal performance. Image courtesy of ICYNENE, Inc.

When considering the make-up of an exterior wall assembly then, one very effective approach is to use a combination system. First, low-density open cell spray foam insulation is used to fill completely the cavities between the studs. Then medium-density closed cell insulation is sprayed as a continuous layer over the exterior sheathing of the stud wall. As a practical matter, the insulation should not be applied in depths any greater than 2 inches at a time (i.e. 2-inch lifts) or per manufacturers' recommendations, in order to allow the insulation to set up, cool and dry properly. The final insulation thickness can vary from 2 inches up to about 5 inches depending on the desired thermal performance of the wall recognizing that the closed cell insulation has a substantially higher R-value per inch than the open cell. It should be noted that the continuous insulation thickness and details will also need to meet the requirements of NFPA 285 and (ASTM E119 if a fire rated wall is required) in order to be code compliant as well.

The final continuous insulation layer thus creates a more fully insulated wall assembly with superior thermal performance that may also allow a smaller stud size to be used. For example, a nominal 4 inch stud that is filled with low-density spray foam insulation of R-3.5 per inch will yield a full depth R-value of about R-13. Adding the layer of medium-density spray foam insulation on the outside at R-6.9 per inch means that even at 2 inches, a continuous insulation layer of almost R-14 is achieved. All together, the combined wall assembly now delivers a total R-value of about R-27 in the same total wall thickness as a 6 inch stud wall that only delivered the approximately R-21 we saw in our previous example. More significantly, though, the thermal bridging effect is dramatically reduced by the continuous insulation layer, so the actual wall performance is far superior and much closer to the total cumulative values than it would be without it. This superior performance is rewarded in energy codes by recognizing the higher overall U-factor of the wall assembly that will come about as a result of the continuous insulation. When installed properly it also directly improves the overall energy performance and contributes to the corresponding energy cost savings of the building as well.

Once applied, the exterior layer of spray foam insulation obviously is not left exposed, but instead a masonry veneer or other exterior wall façade treatment is installed. If attachment anchors are required, then they will need to be installed to the sheathing layer before the closed cell spray foam insulation is applied. From a final design standpoint, the continuous layer of spray foam insulation can be treated like any other insulation in the wall assembly meaning that the final wall appearance and design does not need to be limited by its use. Rather, the enhanced performance and potentially easier installation make it more freeing to work with virtually any compatible façade type (providing it is a NFPA 285 compliant design for the spray foam insulation chosen).

A continuous layer of medium-density closed cell spray foam insulation used in a traditional masonry wall provides durability and energy sealing performance. Image courtesy of ICYNENE, Inc.

In the case of masonry walls that use CMU interior walls and exterior brick façade veneers, spray foam insulation is again a very logical choice. By spraying the continuous layer of medium-density closed cell foam over the outside face of the CMU, a high performance, tightly fitting, and durable insulation layer is created. In addition, the interior CMU wall now gets counted under energy codes and ASHRAE 90.1 as a “mass wall” inside the building envelope. A mass wall of this type helps to regulate temperature swings within an occupied space making the space, and the occupants, more comfortable and less prone to use more energy for heating or cooling.

When insulating masonry walls with spray foam insulation, the traditional method of erecting the CMU wall, applying masonry ties, installing insulation, and then laying up the masonry veneer can still be pursued in the conventional manner. Only, instead of relying on the mason to install the insulation and coordinate the masonry ties around it, now the mason can focus on masonry and an insulation installer can focus on spray foam insulation being applied properly. Once the CMU wall is prepared and ready, then medium-density closed cell insulation can be applied, again in 2 inch lifts, up to the thickness called for in the wall design. The masonry ties or anchors can be insulated tightly around them for best performance. Any openings or penetrations in the CMU can also be appropriately filled and sealed with the spray foam insulation. After the insulation is set and dry then it can be covered with the finish layer of masonry veneer. This rather conventional masonry wall approach has typically relied on a space or cavity being present between the insulation and the masonry veneer for moisture control and water drainage to occur and this should still be maintained when using spray foam insulation too. Since the material is capable of shedding water, this is a logical and very compatible use of this type of durable insulation.

Air Sealing with Spray Foam Insulation

Unwanted air infiltration in exterior walls is a significant issue in controlling the performance of the building envelope. Studies by the U.S. Department of Energy and others have shown that unwanted air infiltration can be equally significant as the insulating values when it comes to the energy performance of a building. It is not surprising then that the latest version of the International Energy Conservation Construction Code and many energy focused building standards now include this topic as a measure of compliance and performance.

Spray foam insulation can be used to completely fill and seal around brick ties and other irregularities in conventional construction. Photo courtesy of ICYNENE, Inc.

Traditionally, air sealing in framed wall assemblies has relied on adding an air barrier layer to the outside of the sheathing and taping or otherwise securing the seams. However, these systems are less than perfect when installed, sometimes being subjected to gaps, tears, and incomplete coverage around openings, penetrations, and other irregularities. Using a continuous layer of medium-density closed cell spray foam insulation on the outside of the wall sheathing overcomes these shortcomings. Since the material prevents air from moving through it, everywhere the insulation is placed to deal with heat transfer it also seals up and prevents air transfer. That will include all of those irregular places in a wall where sheet goods may not easily cover. And, since it is continuously sprayed in place, there are no seams or junctions to contend with.

Air sealing within the stud cavities of a wall assembly has often been lacking in traditional construction. Perhaps the biggest performance issue is the use of conventional fibrous batt insulation that has the ability for air to pass through it. While this insulation has been often seen by contractors as a way to “seal up” a wall assembly, it is in fact a misperception. The notion that “stuffing” an opening, gap, or void with fibrous batt insulation will help seal off any air leaks is not accurate. In reality since fibrous insulation allows air to pass through it, putting it in places to seal off air is not effective. Rather, the use of spray foam within a stud cavity, or adjacent irregular spaces and openings, prevents the flow of air in these locations as well. This is an important point in overall wall performance, because not only does an unwanted air flow carry heat with it, it also likely carries water vapor which can condense inside the wall and cause damage. Hence, using a material that truly stops air flow can directly contribute to the long term durability of a wall assembly.

Finally, the use of spray foam insulation in a stud cavity stops convection currents from occurring within that cavity. Those currents are often found in stud cavities with batt insulation and can work against the energy performance of a building by creating an internal thermal air flow that gets past the insulation. This process starts when the wall surface on the warm side of the wall heats up a layer of air adjacent to it inside the stud cavity. That warmed air will rise to the top of the stud space, pulling air from the cooler face through the bottom of the batt insulation toward back toward the warm side. The warm air will then be pulled down along the cool side and give up its heat—effectively transferring heat out the other side of the wall assembly. The overall effect is to by-pass the insulation completely through this circular flow of rising and falling air currents within the cavity. And the principles of physics behind this convective flow don't particularly care what season it is, the process is the same, just on different wall faces. Either way, the amount of energy needed to operate the HVAC system increases due to the poor performance of the wall. Filling the stud cavity fully with spray foam insulation prevents this cycle of rising and falling air currents from happening in the first place and delivers the true performance of the wall that was intended. Even in cases of a partial fill, where the cavity is intentionally not filled up, a wall cavity insulated with foam will be airtight and convection currents will not be able to form since the temperature conditions for their development in the cavity will not likely exist.

Controlling Thermal Bridging

We've already discussed the dramatic impact of thermal bridging in stud walls where the studs, particularly metal studs, conduct heat directly and short circuit the effect of the insulation. But the same phenomenon can happen in other common building locations as well.

Medium-density closed cell spray foam insulation has been applied outside of the sheathing on this building to form a continuous insulation layer that covers over all potential thermal bridging locations before being covered over appropriately with a brick veneer. Photo courtesy of ICYNENE, Inc.

Consider the condition where a stud wall assembly is used on multiple floors of a commercial building. The studs will rest on and be anchored to a floor structure that is most commonly concrete in a metal deck with a total thickness on the order of 4 to 6 inches or more or a wood framed structure that is much thicker. In this type of construction, the insulation in the wall studs stops above and below the floor structure meaning the floor edge is exposed along the full length and width of the building. It is therefore a very significant thermal bridge since there is nothing to prevent heat from being transferred between the inside and the outside of the building along the entire perimeter of the floor construction. The obvious means to overcome this deficiency is to insulate this edge as part of the overall insulation scheme of the building envelope. Hence, the continuous insulation approach that we employ on the walls can and should be extended over the floor edges as well. Using medium-density closed cell spray foam insulation to significantly boost the performance of stud walls, now also dramatically increases the performance of the overall building by covering the floor edges and combatting this otherwise energy draining thermal bridge. In short, the effectiveness of the continuous spray foam insulation is not limited to just the stud wall areas, but to the entire height of the building across multiple floors on all sides.

Another common wall condition that creates unwanted thermal bridges is the area around structural steel or concrete. In many commercial buildings the studs are not the primary structure, rather a steel frame or concrete system is used with studs or masonry infill between. The structural elements act as direct thermal short circuits just as the floor slabs do if they are not protected. This is true for structural elements that are in line with wall framing but it is also especially true for corner conditions which sometimes protrude and get overlooked. Once again, the most effective solution is to provide continuous insulation over the outer faces of these structural elements to stop the unwanted heat transfers. Medium-density closed cell spray foam insulation will effectively cover all of these areas as well and will be particularly well suited to filling any irregular surfaces caused by fasteners, plates, etc. to create a truly continuous thermal enclosure around the entire exterior wall surface of the building.

Spray foam insulation can fill and seal in and around areas that are difficult or complicated for other insulation systems. Photo courtesy of ICYNENE, Inc.

One final area to address in regards to thermal bridging is not related to the horizontal transfer of heat through the wall system, but rather the vertical transfer of heat that can occur up through a roof parapet. Commonly a parapet extends above the roof line meaning that it extends above the roof insulation level. Often, the thought has been to simply stop the wall insulation at the height where the roof insulation begins. But that leaves the parapet exposed to the exterior without anything to impede heat transfer. In effect, it is doing in the vertical condition what the floor edge was doing in the horizontal condition. By now the solution here should seem obvious—extend continuous wall insulation all the way up the face of the parapet to the top. Then, to complete the envelope enclosure, extend the roof insulation up along the other side of the parapet so the two insulation systems meet at the top of the parapet and close off the thermal bridge. There are a number of ways to detail this, but the intent is the same – stop the unwanted transfer of heat into or out of the building along the entire perimeter of the building. Of course, if there is no parapet at all then the detailing may be a bit simpler, but the important point will be to extend the continuous insulation up the full height of the wall assembly and the roof insulation over it so a truly continuous thermal envelope is created. The same medium-density spray foam insulation used elsewhere on the wall for continuous insulation will work very well here to fill in and close that juncture.

The significance of addressing thermal bridging cannot be overstated. As the above discussion shows the wall area that is compromised in typical building construction without continuous insulation is not limited to the 20 percent or so that we saw in stud wall construction. Rather, by factoring in the effects of floor edges, structural components, and parapets, the total un-insulated area on a building façade could be 30, 40, or even 50 percent depending on the make-up of those systems. Therefore, adding continuous insulation over all of these areas and integrating it across the full wall construction areas will have a significant impact on actual energy performance of the building and the comfort of its occupants.

Conclusion


Spray foam insulation offers a complete energy performance solution for wall construction in commercial design. Low-density open cell spray foam insulation provides an ideal means to completely insulate stud cavities while eliminating the potential for internal convection currents that could otherwise reduce performance. It also provides an effective air barrier to seal all areas and openings in a framed wall cavity. Medium-density closed cell spray foam insulation provides a high-performance solution for adding continuous insulation and an air barrier all in one product on the outer surface of sheathing on a framed wall. It will also cover smoothly and completely over all of the areas that could otherwise provide energy draining thermal bridges. The end result is a total high performance wall assembly solution that can enhance and work with virtually any architectural design approach. And, by virtue of that higher performance, the building owner will reap the benefits of energy cost savings and longevity of building for years to come.

Peter J. Arsenault, FAIA, NCARB, LEED AP, designs, consults, and writes about energy-efficient buildings nationwide. www.linkedin.com/in/pjaarch

The evolution of insulation starts here. Icynene’s spray foam insulation products are specially formulated to meet the needs of builders, architects, and homeowners. www.icynene.com