Spray Foam Insulation for Walls and Attics

Using Spray Foam to Create Air Barriers on Exterior Walls

By John Broniek

When selecting air barrier products to employ in building designs, architects have a broad range of choices. Spray foam insulation products are often selected because they can provide superior performance and also contribute to greater energy and operating cost savings in buildings. In particular, closed-cell (medium density) and open-cell (low density) spray-applied polyurethane foam (SPF) can insulate and air seal wall assemblies in commercial buildings quite effectively, economically, and efficiently. Its air-sealing characteristics, along with the ability to minimize moisture and temperature-related issues, and capacity to enhance the performance of a wide variety of building types makes it ideal for commercial projects. At the same time, more design freedom because of the custom, field-applied nature of the system is realized. As a result, these products are becoming a popular alternative among architects when designing exterior walls for airtight construction.

Background

The need for air barriers in exterior walls is well understood in the building community. Effective air barriers have positive impacts not only on heating and cooling energy costs, but also on moisture problems, indoor air quality (IAQ), and acoustics. This is because moving air can carry unwanted moisture, contaminants, or noise into a building. Overall, proper air sealing with an air barrier system results in more sustainable and durable buildings addressing numerous green design issues such as more efficient use of construction resources.

There is a realization among the design community an air barrier system is a combination of components within the building enclosure, which typically includes a primary air barrier material. The system components are designed, installed, and integrated in such a manner as to stop the uncontrolled flow of air into and out of the building enclosure.

Air barrier material performance

To be a qualifying air barrier material, the air permeance of a product must be equal to or less than 0.02 L/(s·m²) (0.004 cfm/sf) when tested at an air pressure of 75 Pa (1.57psf). The testing basis for this rating is ASTM E2178, “Standard Test Method for Air Permeance of Building Materials.” Closed-cell, medium-density, SPF products are required to have this testing conducted to meet the requirements of the Underwriters Laboratories of Canada (CAN/ULC) S705.1-01, Standard for Thermal Insulation – Spray Applied Rigid Polyurethane Foam, Medium Density – Material – Specification.

The National Building Code of Canada (NBC) notes in Appendix A generic, medium- and low density 25-mm (1-in.) thick polyurethane spray foam have air permeance characteristics that would result in both qualifying as an air barrier material. Medium-density spray foam insulation normally is installed at a nominal 32 kg/m³ (2.0 lb/cf) density while low-density spray foam is installed at a nominal 8 kg/m³ (0.5 lb/cf) density. In addition, in the American National Standards Institute/American Society of Heating, Refrigerating and Air-conditioning Engineers/Illuminating Engineering Society of North America (ANSI/ASHRAE/IESNA) 90.1, Energy Standard for Buildings Except Low-rise Residential Buildings, both SPF product types are recognized as air barrier materials. Product manufacturers should be consulted for ASTM E2178 test results that indicate the thickness of a specific product for it to qualify as an air barrier material.

Air barrier system performance

The Canadian Construction Materials Centre (CCMC) has developed a Technical Guide for Air Barrier Materials describing the criteria for the assessment of mechanical and physical properties of air barrier systems for exterior walls of low-rise buildings for the purpose of obtaining a CCMC Evaluation Report. Although low- and medium-density SPF products are eligible to apply for a CCMC Air Barrier Systems Report, currently just a small number of medium-density SPF products have obtained it and only for exterior continuous insulation (ci) wall applications.

According to the technical guide, an air barrier system must:

  • have an acceptable low air leakage rate;
  • be continuous and durable;
  • have sufficient strength to resist the anticipated air pressure load; and
  • be buildable in the field.

Applications

A significant installation benefit of medium-density spray foam insulation is its ability to conform directly to the wall (sheathing or structural) surface regardless of shape, geometry, or irregularities. It can be employed on the exterior or interior side of a wall and fully covers and seals the underlying construction to provide a truly continuous uninterrupted insulation layer. The result is, for example, curved buildings have traditionally needed a very labor-intensive process where rigid foam boards had be cut to shape and then excessively taped at each joint, but this can now be replaced with a quick, smooth, and far less labor-intensive installation.

For exterior as well as interior ci applications, medium-density spray foam insulation has the key attributes needed for wall performance. These include:

  • an integral air barrier based on material testing as mentioned earlier;
  • high long-term thermal resistance (LTTR) insulation values per CAN/ULC-S770, Standard Test Method for Determination of Long-term Thermal Resistance of Closed-cell Thermal Insulating Foams, testing;
  • a vapour barrier, typically at a 50-mm (2-in.) thickness or greater, based on water vapour permeance testing per ASTM E96, Standard Test Methods for Water Vapor Transmission of Materials, thereby eliminating the need for a polyethylene (PE) vapour barrier at the inner portion of the wall; and
  • a water-resistant barrier (WRB) since it is capable of shedding water (when integrated with flashings around penetrations and key wall transition points a durable water-resistant system is formed).

Air barrier systems

In the CCMC Air Barrier System evaluations, the medium-density SPF product is considered as the principal material in the plane of airtightness for the air barrier system. To qualify as an air barrier system, the wall needs to accommodate movements of building materials, and provide connections to adjacent materials to prevent air leakage at all critical locations including connections, joints, and penetrations. An extensive number of tests are conducted to receive the air barrier system designation including air barrier system testing.

To achieve air barrier system compliance, it is recognized the use of medium-density, spray foam products in exterior ci wall applications requires membrane materials (self-adhered or liquid) to provide optimum air barrier system performance. Consequently a great deal of effort in field evaluations and product compatibility testing has been made by manufacturers to define the components of such a system and where they should be used.

Design and performance considerations

The use of medium-density spray foam insulation in exterior ci applications provides architectural firms and commercial building contractors a great opportunity to positively impact their building schedules, budget, and overall performance quality. Additionally, medium-density spray foam insulation in exterior ci insulation applications offers many benefits including:

  • can cover the widest range of exposed surfaces to prevent thermal bridging;
  • features an approach to air- and water-resistive barrier creation not dependent on extensive use of joint sealants in exposed situations;
  • has a much better ability to bond to the entire length of wall penetrations, such as brick ties and fasteners, thereby better ensuring thermal and airtightness effectiveness;
  • is less likely to have air barrier discontinuity at transitions and control joints;
  • has very low water absorption and is capable of shedding water; and
  • can be applied in cold temperatures as low as -10 C (14 F).

There can be challenges associated with SPF exterior ci, most of which can be overcome with attention to details and pre-application planning. Dry and non-windy weather conditions are necessary to facilitate optimal product adhesion and limit over-spray situations. The application area should be isolated and other construction trades restricted from entering. Confirm the substrates the spray foam will be applied to are compatible with it. Develop a plan to ensure wall penetrations including windows, doors, anchors, and attachments are covered or will be remediated so the spray foam does not affect their long-term operation.

Using open-cell, low-density spray foam insulation

Although it has most often been associated with residential construction, low density spray foam can also be used on the interior side of a commercial building. Its air-sealing characteristics allow it to qualify as an air barrier material. Many spray foam manufacturers have the appropriate test information to confirm that ability. Therefore, using open-cell spray foam within a wall cavity, with either metal or wood studs, can constitute the main component of an air barrier system. Its use also means expensive air membranes on the exterior of the wall sheathing can be avoided or scaled back in scope, thereby reducing construction costs. Other benefits of using open-cell spray foam include being better able to be sprayed on cold substrates and employed in cold weather applications. It can be used for applications on wood-based substrates, and it is also compatible with concrete, masonry, and steel. Open-cell spray foam can be cut fairly easily allowing for changes, such as adding an electrical box within a wall stud cavity, to occur more simply.

Open-cell spray foam insulation effectively blocks heat transfer with a tested thermal performance of approximately 0.66 to 0.72 (m2•K)/W (R-3.7 to R-4 per in). Its lower density gives it a comparatively softer make-up than denser, closed-cell insulation, meaning it can also seal around the edges and perimeter of stud cavities and any penetrations in a flexible manner. Some of the other benefits of open-cell insulation are tied to this lighter, softer, and more flexible make up. Acoustic control, for example, is enhanced in wall assemblies due to its flexible and absorptive properties, more so than with rigid insulation. Should water infiltrate the assembly for any reason, its vapour permeability means 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 mould. The cost of open-cell spray foam insulation is generally very attractive and competitive when compared to labour and materials for other types of insulations.

Installing spray foam insulation within building interior assemblies are typically less challenging than exterior applications. Isolating the application area and having the substrates ready for spraying are still necessary. Further, the building construction should be far enough along so the installed SPF will not be subject to weather—if windows are not in place it is good practice to cover their openings.

As with all construction products, installation is critical to the performance of the material and development of a good performing wall air barrier. spray foam installers who have successfully undergone training at the hands of manufacturers or a trade association are more likely to deliver the installation needed. Specifically, the Canadian Urethane Foam Contractors Association Inc. (CUFCA) has an installer certification process that includes training and licensing.

The advantages of using spray foam insulation to create an air barrier on exterior walls are numerous. Using medium-density SPF products in an exterior ci wall application has been proven to create an airtight wall assembly and is becoming widely specified. Meanwhile, low-density SPF products are a cost-effective approach to creating airtightness within wall stud cavities. In both cases, the result is a more energy-efficient building.

John Broniek is senior engineer for Icynene-Lapolla. where he provides product use recommendations to all external audiences including designers, applicators and building owners. He also acts as a building science technical resource to Icynene-Lapolla’s sales team, dealers, and community. Broniek has been involved in improving the energy efficiency and durability of buildings throughout North America since 1990. Broniek can be reach at jbroniek@icynene-lapolla.com.

The Multiple Purposes of Air Barriers

by Jay Saldana, PE
The need for energy efficient buildings is the largest driving factor behind product innovation and building science advancements in air barrier materials. However, other equally important aspects of modern construction are sometimes overlooked by building professionals.

Manufacturers continue to improve their products to extend a building’s durability and lower the costs of construction. The developments in air barrier products over the years reflect a constant demand for airtight, mechanically ventilated buildings to meet ever-changing energy codes and expectations among builders and architects for higher performing facilities. There is also pressure to find ways to design a building that could function properly in any type of climate or environment. Therefore, understanding the progression of air barrier materials will help professionals at all levels of the building design process choose the best air barrier system for their project.


Evolution of air barrier materials
The importance and inclusion of an air barrier material is not questioned by today’s builders and architects, but not long ago, a structure’s air barrier was not composed of one single membrane. With painstaking detailing of joints and transitions, interior gypsum was largely employed to reduce air leakage, knowing it had the help of other materials in the exterior wall for slowing down leakage. Since then, the function, design, and construction of an air barrier, not to mention how it is specified, has been constantly changing. It is important to remember how far the products and systems have come to fully appreciate and better understand how to utilize them in present day construction.

Building wraps were among the early products to act as an exterior air barrier material and had the advantage of being vapor permeable. Even after the creation of the U.S. Department of Energy (DOE) in the late 1970s, there was still a lack of advanced science and consensus of where vapor retarders and insulation should go in an exterior wall. A “breathable” exterior wall (i.e. a wall with materials facilitating drying by air movement or vapor permeability) was thought to be the only way to prevent moisture damage. Building wraps could fit this design method by allowing vapor through the material but preventing the passage of liquid water and air.

Installation of the wraps was the biggest challenge. They had to be fastened frequently and attached with precision. It was not uncommon to see wraps flapping in the wind on a construction site simply because it was not taped at the joints or attached to the building correctly. The product itself worked, but the method in which it needed to be attached and the lack of high-quality workmanship in installation led to the next generation of air barrier materials.

Self-adhered membranes
When self-adhered membranes came into the market, they were instantly thought to be superior to wraps as they adhered to walls without the need of a fastening pattern. Some contained self-healing qualities and sealed screw penetrations or small slices made to the membrane during construction. While these products proved more reliable, the installation process was long and depended on temperature-sensitive adhesives. When these products were first introduced, there was a period of trial and error by manufacturers with adhesives—some work better in the heat, some in the cold, and very few work well in both. Dirty and dusty substrates also contribute to adhesive failure. The self-adhering membranes sometimes required a termination bar that had to be fastened down over the membrane edge as it was common for certain edges of the membranes to peel.

Closed-cell spray foam insulation tackles design challenges and problem areas like oddly shaped structures and curves that are difficult or nearly impossible with other types of insulation.
Closed-cell spray foam insulation tackles design challenges and problem areas like oddly shaped structures and curves that are difficult or nearly impossible with other types of insulation.

Originally, peel-and-stick membranes were vapor impermeable, but as the breathable exterior wall concept spread, manufacturers developed vapor permeable versions. This transformation required years of research and new technology to allow vapor through the adhesive and the facing of the membrane.

 

Fluid-applied barriers
Fluid/liquid-applied barriers were another jump in the air barrier product industry. The first versions could be spread by trowel and adhere in place on the wall, thereby becoming both the air and water barrier. Spray and roll-on versions were created as thinner applications but both thicknesses accomplished the same goal of being the air and water barrier. While self-adhering membranes evolved over time, the manufacturers of fluid-applied barriers learned from their predecessors, and soon had both vapor permeable and impermeable versions. Fluid-applied barriers are thought to have even less possibility for error in installation than self-adhered membranes. They can cover corners and angles better than self-adhered membranes, which take some skill to accomplish the tricky bends and folds. While this was a huge advancement and reduced the time of installation, in the author’s experience, the higher cost of these products often resulted in them being “value engineered” out of the project.

A further advantage of fluid-applied barriers over self-adhered membranes is the lack of the membrane itself. Often, compatibility with various caulks and sealants must be tested not only with the adhesive, but also the membrane. Fluid-applied barriers are more often compatible with such construction materials and capable of being applied to them. A self-adhered membrane would have a very hard time transitioning and adhering to an irregular surface such as the face of closed-cell spray foam. Conversely, a fluid-applied product can fit into the irregularities of the surface and achieve a solid bond. In constantly wet climates, such as the State of Washington, caution must be taken with self-adhered membranes as their adhesive is typically sensitive to wet surfaces. Many fluid-applied barriers advertise their applicability while actively raining so work may continue.

The ability to self-support and adhere to common construction materials, including itself, allows spray foam to be installed much more quickly than rigid foam board and it does not have any joints to treat.
The ability to self-support and adhere to common construction materials, including itself, allows spray foam to be installed much more quickly than rigid foam board and it does not have any joints to treat.

Advent of continuous insulation
The changes and advancements in energy codes, specifically the 2009 International Energy Conservation Code (IECC), started to require exterior continuous insulation (ci) in most of the eight climate zones.

Knowing vapor permeable air barrier membranes were the newest and fanciest product, and the exterior wall still needed ci, it was not uncommon to find both installed on the exterior side of the wall. If the ci was rigid foam plastic insulation and installed after the air barrier membrane, as it typically is, the vapor permeable properties of the membrane are rendered useless. A wall is only as breathable as its least breathable component and in this case, it is the vapor retarding rigid foam plastic insulation.

This multilayered approach did not allow for vapor permeance to the exterior because the insulation was preventing it from exiting. While this is not necessarily a poor design, it just means the owner paid a premium for an individual air barrier product that is not being used to its full potential. It also means if the mechanical engineer was counting on a permeable exterior wall, some of the HVAC calculations may be off.

Continuous insulation as an air and vapor barrier means the old practice of using interior vapor retarders is no longer necessary in cold climates, and this material can be removed from the assembly. Those vapor retarders were meant to keep warm, humid air from getting into the stud cavity and touching a cold surface. Continuous insulation reduces the chances of having a surface below dewpoint temperature inside the stud cavity and, along with the wall no longer being leaky, the humid air in the cavity will normalize with the interior and be part of the HVAC system’s conditioned air. If any moisture was to leak in the wall cavity, it would now dry to the interior.

As architects and designers were learning the building science of why and how to use ci properly, they were also looking at the increasing cost and number of materials employed in the exterior wall. The need for one multipurpose product on the exterior wall created a business opportunity for rigid foam plastic manufacturers.

Extruded polystyrene and polyisocyanurate
Extruded polystyrene (XPS) and polyisocyanurate (polyiso) insulation manufacturers began to successfully test their products to show they could act as the air and water barrier, vapor retarder, and ci of the building. One product performing all these controls allows the removal of one or more materials from the assembly, such as the individual air barrier, saving installation time and money.

Closed-cell polyurethane spray foam insulation installed on top of a self-adhered membrane.

To accomplish this level of performance, rigid boards need to be mechanically fastened to the walls to resist negative wind pressure. They must also seal every board joint and fastener and through-wall penetrations. Typically, tape is employed to seal the board joints and fasteners, while flashing is used for through-wall penetrating objects. If installed correctly, tape can be effective, but the thousands of foam board joints and tens of thousands of foam board fasteners create potential direct paths for leakage. If the rigid foam board is used as the air and water barrier, it is imperative every joint and fastener treatment be installed correctly.

Closed-cell polyurethane spray foam
Closed-cell polyurethane spray foam has recently been approved as an exterior air, water, and vapor barrier. Additionally, spray foam does not have any joints or fasteners to seal. Rigid polyiso foam plastic insulation and closed-cell polyurethane spray foam have similar performance characteristics. They each have a closed-cell structure that can utilize a blowing agent to achieve some of the highest R-values per inch on the market. Spray foam tops the insulation R-value charts at around R-7.1 per inch. They both perform as an air, water, and vapor barrier. However, spray foam is installed very differently. It is sprayed onto the exterior sheathing (or masonry back up wall), adhering to the surface, and expanding outward to create the desired thickness. Spray foam will self-support and adhere to common construction materials, including itself. This ability allows spray foam to be installed much more quickly than rigid foam board and it does not have any joints to treat. Spray foam can also allow for eye-catching architectural curves in walls to be insulated and sealed easily whereas rigid foam board would require thin vertical strips to make it around the radius.

Spray foam insulation helps expand the horizon of design opportunities for commercial architects beyond what was feasible with fibrous or rigid board insulation options. Architects can allow their creativity to show with the confidence spray foam will help meet the energy efficiency, overall performance, and functional needs of a building. Closed-cell spray foam insulation tackles design challenges and problem areas that are difficult or nearly impossible with other types of insulation, including arches, curves, cathedral ceilings, and transitions from the exterior wall to fluted roof deck over hangs.

Air barriers have evolved from encompassing several different materials with labor-intensive processes to single, multipurpose products making construction faster and more cost efficient when combined with the right design and building science.

Want A Warmer, Comfier Home This Winter? Think About Insulation

Ty Pennington posted this article:

Our homes are our havens, especially in the winter months, when the chilly winter weather can leave you wanting to do nothing else but hibernate.

Don’t shudder at the thought of shivering through winter. Ensure your home is filled with the right elements to keep drafts out and warm, clean air in. While cozy throws and blankets may come to mind, it is the products you don’t see that help to truly make a home comfortable. Products or materials like spray foam insulation.

Read the full article on http://torontostoreys.com/2018/11/winter-insulation/.

ProSeal HFO Spray Foam Featured in Professional Builder

Icynene-Lapolla’s ProSeal HFO closed cell spray foam was recently featured in Professional Builder magazine. You can see it here: https://www.probuilder.com/insulation-icynene-lapolla

Lapolla Expands Distribution to Canada

Icynene-Lapolla, a supplier and manufacturer of energy efficient building envelope solutions has announced it will expand distribution of its Lapolla building materials line in Canada.

In the News

https://www.prosalesmagazine.com/news/q3-2018-dealer-distributor-and-manufacturer-news_o

https://www.roofingcontractor.com/articles/93123-icynene-lapolla-expands-lapolla-product-line-availability-in-canada

https://www.wconline.com/articles/91876-icynene-lapolla-expands-lapolla-product-line-availability-in-canada

https://www.buildingenclosureonline.com/articles/87798-icynene-lapolla-expands-product-line-in-canada

https://www.gupta-verlag.com/news/industry/22124/icynene-lapolla-expands-product-line-availability-in-canada

http://www.coatingspromag.com/industry-news/2018/10/icynene-lapolla-expands-lapolla-product-line-availability-in-canada

https://www.sbcmag.info/news/2018/oct/icynene-lapolla-announces-product-distribution-expansion

https://www.building-products.com/issue/the-merchant-magazine-october-2018/

Keezell-Building-Featured

Keezell Building Article in Walls & Ceilings Magazine

Restoring a Historic Landmark with High-Performance Materials

The five-story brick and glass structure at 122 S. Main St. in Harrisonburg, Virginia, has more than just an address. It has a name and history steeped in tradition. Listed on the National Register of Historic Places, the Keezell Building sits in the city’s downtown area, and is a proud example of classic revival-style architecture. Just after being built, it housed the Daily News Record offices, printing presses, and was named after the paper inhabiting it, being touted as one of the finest and most modern newspaper buildings in Virginia.

Read full article here (opens PDF).

NEW Tax Benefit for Commercial Roofs

NEW Tax Benefit for Commercial Roofs!

The Men Behind the Empire

Big things are happening in the spray foam industry. If you haven’t heard about Icynene and Lapolla banding together, then you’re surely not up to speed on current events! Not to worry though, here’s the 411 you need to know. With the industry arguably reaching a tipping point for mainstream use and acceptance by consumers and builders in the residential and commercial sectors while continuing to strengthen globally, the level of opportunity has increased across the board, which lead to these two long-standing, major manufacturing players to join forces under one umbrella: Icynene-Lapolla.

Read full article here.

Roofing-Contractor-Article

2018: A Pivotal Point in Growth for Spray Foam Roofing

When people think of spray polyurethane foam (SPF), envelope insulation often comes to mind first, as awareness of the energy efficiency benefits of the material have surged in recent years and accelerated insulation applications in tandem. However, spray foam was first proven as a viable, high performance material for roofing retrofits and this is where the product initially built its reputation for durability and energy performance…….

Read the full article in a PDF

Read on RoofingContractor.com

Roofing-Contractor-Article

Roofing Contractor’s State of the Industry Report and Survey 2018

For the past decade, Roofing Contractor has gauged the status of the North American roofing industry by turning to you, our readers, to help identify the issues and trends impacting the overall business climate that drives some contractors to succeed in both residential and commercial sectors…….

Read the full article in a PDF

Read on RoofingContractor.com