Expansion & contraction

Why flexibility is important in roof construction

All materials used in roof systems expand and contract with changes in temperature on a daily and seasonal basis. Even a cooling breeze, a cloud passing overhead or sudden rain shower can cause roof systems to contract. If you don’t take this into account, premature roof failure could occur.

Thermal expansion and contraction issues are responsible for a large percentage of roofing leaks. In the long term, a properly designed weather tight roof will cost less than an improperly designed leaky low-cost roof.

Thermal expansion occurs when heat is added to most materials, causing the material to expand. Consequently removing the heat energy (cooling) causes the material to contract. Each different material type expands at a set rate unique to that material for one degree in material temperature change.

The nature of the way we occupy the buildings under a roof will determine the amount of roof movement over the structural system. In the past, most buildings with metal roofs were used for shade and shelter or utilitarian space – meaning the temperature inside the building was nearly the same as the outside

Engineering flexibility

Our liquid applied roofing systems have been engineered with flexibility at the core

FibreFlex is a technology that enhances our products flexibility without adding any post production additives which can lead to long-term problems with the life cycle of the roof membrane.


250% Elongation at break


200% Elongation at break


3% Elongation at break

Elongation at break

Elongation at break measures the capability of a material to resist changes of shape without cracking, we put all our roofing products to the test.