General contractors have the arduous task of ensuring jobsite safety, construction quality, cost control and timeline objectives—all while satisfying local building codes. Multifunctional building products like spray polyurethane foam (SPF) can offer an advantage to general contractors by meeting multiple objectives in successfully completing commercial projects.

SPF is most well known for its thermal insulation performance. In fact, general contractors may use closed cell SPF to fulfill the “continuous insulation”provision of many energy standards and local building codes. When properly installed, SPF forms a continuous monolithic air control layer around sheathing joints and penetrations such as pipes, conduits and utility lines.  

With its ability to increase energy efficiency, meet or beat sustainability goals, and form a highly effective heat, air, and moisture control layer, SPF is a proven asset to any contractor’s code compliance efforts. By matching the needs of the structure with the performance of SPF, almost any new or existing commercial building can benefit from SPF.

ICC Evaluation Service Report
When choosing a brand of SPF to use, it can be helpful to research the product through industry-trusted mechanisms. The International Code Council (ICC) has a subsidiary called the ICC Evaluation Service that vets building materials to determine if they are acceptable and comply with various industry codes and standards. Generally, the building material manufacturer will request that their product be listed and then use the evaluation service report as a basis for providing technical information and product validation to the industry. It is important for manufacturers to provide an Evaluation Service Report of the SPF so the general contractor will be able to properly install the material in accordance with related codes and industry standards. 

Construction Specifications Institute
The Construction Specifications Institute’s (CSI) MasterFormat® offers a comprehensive list of building products and materials that is defined and organized to help with developing estimates, meeting required building specifications and identifying general product data. SPF is classified in the CSI MasterFormat in Division 7, Section 07210 – Building Insulation. SPF is also classified in other sections of Division 7, including Thermal and Moisture Protection, Thermal Protection, Thermal Insulation, Foamed in Place Insulation, Sprayed Insulation, Weather Barriers, Vapor Retarders and Air Barriers. 

Air Control in ASHRAE 90.1-2013 and 2015 International Energy Conservation Code
The commercial building codes, ASHRAE/IES Standard 90.1-2013(90.1-2013) and the commercial provisions of the 2015 International Energy Conservation Code (2015 IECC) require that the building envelope be carefully designed to limit uncontrolled air infiltration and exfiltration. Controlling air movement is important in humid regions of the country, as humidity can increase the latent load inside the building, requiring the additional use of the building's cooling system to bring the level of humidity down to acceptable levels. Air infiltration in cold climates translates to occupant comfort issues and high heating costs. 

The building envelope includes the roof, wall and floor systems that surround the interior space containing conditioned air. The code provisions require the selection of either building materials or assemblies that do not exceed the maximum air leakage requirements (CFM/ft2). The2015 IECC also allows the building envelope to be tested to not exceed a maximum air leakage rate as a method for demonstrating compliance with the code.

Both ASHRAE 90.1-2013 and the 2015 IECC require that all seams, penetrations and transitions between approved building materials or assemblies are sealed. SPF is on the list of pre-approved materials that are deemed to comply with the maximum air leakage requirement. Specifically, closed cell SPF can be installed with a minimum density of 1.5 pcf (24 kg/m3) and a thickness of no less than 1.5 inches (38 mm). Also, open cell SPF with a density between 0.4 and 1.5 pcf (6 and 24 kg/m3) and having a thickness of no less than 4.5 inches (114 mm) can be used. Certain SPF systems may be installed at thicknesses less than these prescribed numbers if the product is tested and meets the air permeance requirement for an air barrier material at the tested thickness.  

Water-Resistive Barrier Requirements in 2015 International Building Code
Chapter 14 of the 2015 International Building Code (IBC) pertains to exterior walls and specifically addresses water-resistive barriers (WRB) that are designed to protect the building from liquid and vapor water intrusion. Section 1403.2 addresses weather protection and stipulates that exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing and be designed and constructed in such a manner as to prevent the accumulation of water within the wall assembly. This is accomplished by including a water-resistive barrier behind the exterior veneer and creating a means for draining water that enters the assembly to the exterior. 

In addition to this, the WRB must be constructed with a minimum of one layer of No.15 asphalt felt, complying with ASTM D 226 for Type1 felt or other approved materials, which shall be attached to the studs or sheathing in such a manner as to provide a continuous water-resistive barrier =behind the exterior wall veneer. For the WRB code requirement, closed cell SPF is a pre-approved material for commercial building water barriers. Chapter 26 of the IBC, section 2603, specifically refers to foam polyurethane insulation and should also be referenced when specifying SPF for a commercial building project. 

National Flood Insurance Program (NFIP) Regulations
Section 60.3(a)(3) of the NFIP regulations requires that the community review all permit applications to determine whether proposed building sites will be reasonably safe from flooding. If a proposed building site is in a flood-prone area, all new construction and substantial improvements shall be constructed with materials resistant to flood damage. In the NFIP, closed cell SPF is specifically listed as an approved flood resistant material.

Proper Application With Certified Applicators
In compliance with the American National Standards Institute (ANSI)/ISO 17024 standard, the Spray Polyurethane Foam Alliance (SPFA) has created a certification program specifically for spray foam applicators covering safety, installation practices and proper applications. When choosing SPF for a project, it is important to specify that all trade contractors and SPF installers have the most recent industry-recognized certification. For more information on the SPFA certification program, visit www.sprayfoam.org


Trent Shidaker is a business manager for Huntsman Polyurethanes. For more information, visit www.huntsman.com/sprayfoam or follow @Huntsman_Corp.