Fibreglass Chopped Strand Mat

Chopped strand mat (CSM) is the glass fibre reinforcement that gives a GRP laminate its strength, forming the structural core of every fibreglass flat roof, boat hull, or moulded component. Strands of glass fibre are randomly distributed and lightly bonded together to create a mat that wets out easily with resin and conforms readily to flat and gently curved surfaces, making it the standard reinforcement choice for roofing and general laminating work.

This range covers two of the most widely used CSM weights: 450g and 600g per square metre. The 450g mat is a popular choice for roofing applications and general-purpose laminating where a finer, easier-to-wet-out mat is preferred, while the 600g mat offers a heavier reinforcement for situations where additional strength or fewer laminating layers are needed. Both are available in roll sizes from 1kg up to 25kg, allowing the right quantity to be ordered for everything from small repairs to full roofing projects. To complete your roofing materials checklist, browse the full Flat Roofing product range.