Commercial properties are typically equipped with a flat roofing system, which consists of a layer of foam board insulation between the outer roofing material and the substrate. Doubling the insulation and installing it in a staggered manner has been observed to provide several benefits. L
How Does Staggered Insulation Layers Work?
Air infiltration is one of the most common problems of flat commercial roofs. Infiltration occurs when air from the indoor space – usually hot and moist air – rises through the substrate. Foam board insulation has gaps between boards to allow for thermal expansion and contraction. These gaps unintentionally act as vents that allow the rising air to infiltrate the outer roofing layer. With nowhere else to go, the hot and moist air would add stress to the outer roofing layer. Seams may get torn apart, or it may cause ballooning.
Adding a second layer of insulation, installed in a staggered fashion, can help prevent air infiltration. The foam board insulation at the top would be blocking the vents created by the gaps, effectively preventing uncontrolled airflow. It also helps prevent air leaks from the outside, helping reduce the likelihood of a roof leak in case the roof is punctured.
In addition to preventing air infiltration, the double layer of insulation helps reduce heat that would otherwise have been absorbed through the roof. Combined with a reflective outer roofing, staggered insulation can help reduce your building’s indoor cooling requirements, which can lead to energy savings. The thicker insulation also adds resiliency against impact damage and foot traffic.
Installing a second layer of insulation can also help address existing pooling water, which can damage the roof in many ways if not addressed. “Flat” roofs are, of course, not actually flat. They have an almost unnoticeable slope that allows rainwater to flow towards the drains. Standing water would occur if the roof is improperly designed or if one or more parts of the roof have settled, creating indentations. The second insulation layer can help address such issues and prevent pooling water.
Tedrick’s Roofing is your leading provider of roofing services. Give us a call at (877) 212-9355 and (253) 499-9660. You can also fill out our contact form. We serve customers in Auburn, WA, and surrounding areas.