How to Use Polyiso Insulation in Cold Climates

How to Use Polyiso Insulation in Cold Climates Polyiso insulation is an effective solution for energy-efficient construction, but its performance can vary in cold climates. Here's what you need to know: - High R-Value: Polyiso offers an R-value of 6.0–6.8 per inch, but this drops to 4.5–5.0 per inch in temperatures below 50°F. - Cold-Weather Adjustments: In colder zones (ASHRAE(https://www.ashrae.org/) 5–7), use at least 2 inches of polyiso or pair it with other insulation. Consider R-values measured at 40°F for accuracy. - Installation Tips: Stagger layers, seal joints with foil tape, and use spray foam for gaps to prevent air leaks and condensation. - Applications: Suitable for walls, roofs, and crawl spaces. Exterior installation prevents thermal bridging and keeps structural elements warm. - Moisture Control: Proper sealing and vapor barrier placement are critical to avoid condensation and structural issues. Why Exterior Insulation Changes Everything: Polyiso + Mineral Wool + Z-Gir...