What is the most popular type of flat roof insulation boards used in industrial and commercial buildings in Canada? If you guessed polyisocyanurate, commonly known as polyiso, or ISO, you’re right. Polyiso accounts for more than 75 percent of insulation board feet found in building construction throughout North America. This type of insulation is most commonly used in low-slope roof assemblies and for above and below-grade wall applications.
What is Polyiso Insulation?
Polyiso is a closed-cell foam created by heating chemicals and synthetic materials into a composite material that cools into rigid-foam panels. Polyiso has four major components: MDI, polyol, a blowing agent and a flame retardant. Facers and facing materials contain the foam core during the production process. When installed, they add strength and stability to the finished board. Polyiso is a continuous insulation across all structural members without thermal bridges other than fasteners and service openings.
One of the primary features is polyiso’s high thermal properties, which provide outstanding insulation protection and help to reduce heating and cooling costs. The Rvalue of ISO is typically 5.7 per inch. Depending on the roof’s drainage system, the roofer will install one of two types of boards–flat stock or tapered panels. The boards are available in 4’ x 4’ or 4’ x 8’ sizes, in a range of thicknesses from one to four inches. Pricing is based primarily on the thickness.
Is Polyiso Easily Available?
Polyiso is typically in plentiful supply, but has been harder to procure over the last couple of years. A chief factor is that COVID disrupted the supply chain of MDI, one of the raw materials used to make polyiso. This situation worsened after winter storm Uri in 2021. Pent-up demand has required roofing contractors to be creative with new sourcing, procurement, storage, and financial capabilities.
Why is Polyiso Insulation ideal in the Greater Toronto area?
Increasing stringent standards for constructing buildings have driven the need for new materials that meet a variety of performance metrics. For example, polyiso passes relevant codes set by the National Research Council of Canada (NRC) on behalf of the Canadian Commission on Building and Fire Codes (CCBFC) and other regulatory bodies. And polyiso does much more besides.
This article has already pointed out some of polyiso’s benefits for commercial roofing. Here are the 10 reasons why polyiso is ideal for low-slope roofs:
1. Continuous Insulation
Continuous insulation provides uninterrupted thermal insulation, with no holes or infiltrations in the envelope of the building. This contributes to lower energy loss, decreased air leakage, and minimized moisture.
2. Thermal Efficiency
With the highest R-value per inch in the industry, polyiso is the most effective thermal insulation product on the market. In cold climates such as Canada, its high thermal resistance helps save money on expensive heating and cooling costs.
3. Service Temperature
The product can withstand from the lowest to the highest temperatures that a product can stand without losing its physical characteristics—known as service temperature—making it possible to apply polyiso with hot bitumen.
4. Fire Resistant
Compared to other commercial insulation products, polyiso provides a high R-value per inch, meets the criteria of ASTM E84 Standard, and shows superior performance in fire tests.
5. Meets the Requirements of Building Codes
Polyiso is the only foam plastic insulation product with both FM 4450 and CAN/ULC-S126 approvals–referenced in many Canadian and U.S. building codes–when installed directly over a steel deck.
Polyiso has no CFCs or HCFCs, making it environmentally friendly. Using polyiso panels can help builders obtain numerous LEED credits, a global rating system for healthy, efficient, carbon, and cost-saving green buildings.
Polyiso is compatible with most solvents used in construction adhesives, has excellent absorption for both hot mopping and adhesive attachment methods, plus performs well with mechanical fasteners.
8. Moisture and Vapor Resistant
With its closed cell structure, polyiso resists water absorption, creates a weather resistant barrier, reduces the potential for condensation, and protects the waterproofing membrane.
Because Polyiso retains its original dimensions, it minimizes the chances of thermal bridges that can reduce energy efficiency. The rigidity will also prevent collapse when used for vertical wall upturns. Further, polyiso won’t deteriorate or lose its thermal performance during the service life of the building.
The insulation boards are light and are easy to transport, cut, and handle during installation. When properly protected, polyiso is not affected by oil-based waterproofing compounds, insecticides, or fertilizers.
Call the Toronto Commercial Roofing Experts
Polyisocyanurate insulation is thermally efficient, fire resistant, environmentally friendly, and one of the most cost-effective insulators for your commercial building. Wherever you are in the Greater Toronto area, Elite Roofing is ready to work with you, determining which insulation is ideal for your building and installing it with expert workmanship. Contact us today.