Chopped Strand Mat 450g Full Roll (73 metres)

450g Chopped Strand Mat (CSM) is the most commonly used reinforcement within GRP fibreglass roofing systems. Manufactured from E-glass fibres randomly distributed and bonded together with an emulsion binder, the mat provides the structural reinforcement of the laminate when combined with polyester roofing resin.

The 450g grammage refers to the weight of glass fibres per square metre of matting. In GRP roofing systems, the structural strength of the finished laminate comes from the combination of chopped strand glass reinforcement and polyester resin, as resin on its own becomes brittle once cured.

450g matting is widely used as the standard glass weight across the roofing industry, providing an excellent balance of strength, durability and workability for most flat roof applications.

Compared with heavier reinforcement such as 600g chopped strand mat, the 450g version is more malleable and easier to work around roofing trims, corners, outlets and upstands, making it particularly suited to roofing installations.

The consistent fibre distribution allows for fast wet-out and easy resin flow through the mat, helping installers bring the resin through the laminate efficiently. This promotes good consolidation, reduces trapped air and produces a high quality laminate surface which facilitates topcoat application and helps achieve strong adhesion and full topcoat colour opacity.

As a general guide for roofing laminates, installers typically use approximately 1.5kg of resin per m² when laminating with 450g chopped strand mat, including an allowance for normal installation wastage. For a full roll this equates to approximately 100kg of resin.

450g chopped strand mat is suitable for a wide range of GRP roofing applications including:

• DIY fibreglass roofing projects

• Professional GRP roof installations

• New build flat roofs

• Extensions and orangeries

• Dormer roofs

• Garage roofs

• Full rip-off roof replacements

• Roofcell overlay systems

This product is supplied as a full roll measuring 73 metres long x 1 metre wide, making it ideal for larger roofing projects and continuous laminating work.

Full rolls generally provide the best value per metre compared with smaller roll sizes. They can also be stored without a shelf life when kept in dry conditions, making them a practical option for professional installers who regularly carry out GRP roofing work.

Sizes Available

450g chopped strand mat is available in multiple sizes to suit different project requirements:

• Full Roll – 73 metres

• Half Roll – 36 metres

• Quarter Roll – 18 metres

• Cut per metre available

For heavier reinforcement requirements, 600g heavy duty chopped strand mat is also available in quarter, half and full roll sizes (metre lengths differ due to the increased glass weight).