Expansion & Contraction

Why flexibility is important in roof construction

Movement in roofs is mainly caused by thermal expansion and contraction of the roof structure or insulation. Thermal expansion occurs when your roof heats up and cools down from increases in temperature or changes in weather conditions. These movements must be taken into account and allowed for in the design of the roof or premature failure could occur.

FibreFlex Technology

Engineering material flexibility

To try combat the effects of thermal expansion and contraction, our engineering team developed FibreFlex, a technology that enhances the products flexibility without adding any after market additives which can lead to problems in the life cycle of a roof membrane. Our products not only offer unparalleled flexibility in their respective product category they are backed up with expert technical support and a nationwide network of approved installers to ensure the best products and practices are used on the project from start to finish.

Test Results

Putting FibreFlex to the test

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, here are the results below.



A standard polyester GRP roofing system will provide around 1% elongation, this is often increased to 2% by adding a post-production plasticiser. Fibrelast with the FibreFlex technology offers 3% as standard without the need for any additives.



Fibrecoat is our flagship roofing product and is a polyurethane based fibreglass roofing system which is more flexible than standard polyesters. The product will offer over 25% elongation at break when used in conjunction with our 225gm fibreglass reinforcement mat.



Monopol is based on the same technology as Fibrecoat, although its main purpose is to be used as a professional roof repair and refurbishment product it will offer over 30% elongation.