A typical commercial roofing system is equipped with a layer of foam board insulation between the substrate and the outer layer. Roof companies have observed significant benefits derived from staggered insulation layers. In this blog, Roofing by Curry shares a look at how your commercial property can benefit from this type of insulation.

Staggered Insulation Layers
One of the most common problems of a typical commercial roof with a single layer of insulation is air infiltration; not from the outside, but from interior spaces. Board insulation needs to have gaps for expansion and contraction. However, this also acts as vents that let moist air infiltrate the space between the insulation and outer roofing layer. On a single-ply roof, this would put additional strain on the seams, and if the membrane was installed loose-laid, the roof would start ballooning.
Staggered insulation feature two layers of board insulation. Commercial roofing contractors would install the boards in a staggered fashion, with the top board overlapping the gaps at the bottom by at least 6 inches. In addition to preventing air infiltration from indoors, it also works in the other direction by preventing infiltration in case of a punctured roof.
Additional Benefits
Sealing the insulation board gaps without eliminating them helps reduce air leaks. Combined with a double layer of insulation, staggered insulation layers can improve your commercial roof’s energy performance. It also adds resiliency to the roof: an ideal feature if you are expecting foot traffic.
Adding a second layer of insulation can help address ponding water problems. So-called “flat” roofs are not really flat, but rather has a gentle, almost imperceptible slope. It allows rainwater to flow towards the drains. Sometimes, standing water would collect on the roofing surface if the roof is improperly designed, or if a part of the roof settled. The second insulation layer, if properly installed, can help correct the slope problem and prevent ponding water.
Roofing by Curry is your leading provider of residential and commercial roof repair and installation services. Give us a call at (941)-270-4770 or fill out our contact form. We serve customers in Sarasota, FL, and surrounding areas.