Commercial and residential roofing systems are built using materials that have different expansion and contraction rates. This means that when exposed to different outdoor temperatures, some of these layers move differently than the others, causing roof substrate movement. Advanced Roofing takes an in-depth look at this phenomenon and how its effects can be minimized.
What Causes Roof Substrate Movement?
To illustrate roof substrate movement, let’s look at a similarly built installation: paved roads.
Roads are installed using concrete slabs, topped with asphalt. Both materials expand and contract differently when exposed to temperature extremes. Concrete slabs are spaced apart because if installed too closely, there wouldn’t be any room for expansion and the slabs would exert pressure against each other.
Roofing systems are similarly installed with different layers. The substrate or decking is usually made of plywood or OSB (oriented strand board). It expands and contracts when exposed to heat, resulting in roof substrate movement. If the boards are properly spaced by local roof repair contractors during installation, it shouldn’t affect the other roofing layers.
Minimizing the Effects Roof Substrate Movement
Roof substrate movement can be a problem if the boards are spaced too tightly that they push against each other during hot days. The pressure can cause unnecessary stress that leads to damaged decking. Proper moisture levels during installation are likewise important. Using substrate that’s too dry will dramatically expand when the humidity rises. Substrate with high moisture content can drift apart as it dries, pulling the underlayment and shingles along with it, creating noticeable cracks.
A capable roofing contractor should be able to anticipate these problems by supplying substrate that has the right moisture levels. At Advanced Roofing, we factor in roof substrate movement when we choose the roofing materials to be used, in relation to the roofing structure and the owner’s chosen roofing system. Other factors such as attic ventilation and use of moisture barriers are also considered and help minimize the long-term effects of roof substrate movement.
To learn more about our residential and commercial flat roof repair, installation, and maintenance services, call Advanced Roofing today at (630) 473-3008. You can also fill out our contact form to schedule a no-obligation free estimate. We serve Naperville, IL, and surrounding areas in Illinois.