Metal Roof Thermal Expansion

Designing metal roofs for thermal movement.

Metal roof thermal expansion.

One of the most common questions that many people often have about metal roofs is whether or not they will expand and contract. It is important to note ambient air temperature will differ from the temperature of the metal and direct solar radia tion plays a major role in this process. I had a standing seam metal roof installed on my thermal expansion 1 10 2005 within the noise discussion of the residential metal roofing forum. A number of myths often circulate about metal roofs.

These thermal expansion values are meant to provide a general idea of how much various materials expand and contract due to temperature change and should not be used if precise values are needed for critical engineering calculations. Even a cooling breeze a cloud passing overhead or sudden rain shower can cause roof systems to contract. Metal is a rigid material and as with all rigid materials metal expands and contracts when temperatures change. Metal roof systems can be the least forgiving of all roof sys tems if provisions for expansion and contraction are neglected.

It is true that metal roofs will expand and contract. The roofing membrane materials listed below will typically develop smaller clte s as they age. When precision is necessary always refer to the data sheets of the actual specific product you intend to use. Thermal expansion contraction is responsible for most roof leaks.

This is because metal roofs tend to heat up when the sun rises each morning. If you don t take this into account premature roof failure could occur. Metal roof thermal expansion. In the long run a properly designed weather tight roof will cost less than an improperly designed leaky low cost roof.