GRP roofing trims

Product information and application guide

Product overview

GRP roofing trims are often seen as a commodity item by some contractors and over the years cheaper products have flooded the UK market and reduced both strength and quality.

When choosing a trim you need to be looking for strength, some cheaper products are almost transparent in nature and can be flexed really easily. While the price might be good they can be cracked really easily which could mean an expensive repair job.

The Fibrelast GRP roofing trims that we supply are manufactured in the UK to ISO9001 standards and are made with 600gm fibreglass making them super strong and able to withstand ladders and other objects. Here's a quick run down of all the trims and corners available.

Corners and closures

Although the corners aren't really used by the professional GRP roofing contractors (they make their own on site using the fibreglass and base resin) they are a quick way to get a professional uniform finish without the hassle of making them from scratch.

Flat flashing

This product comes in 20 metre rolls or can be cut and sold by the metre. Flat flashing is mainly used at the intersection of a pitched roof and flat roof often found on dormers.

Fascia trims

These trims are sold in both 3 metre and 1.5 metre lengths. The trim is fitted to the lowest edge of the roof usually where the rainwater flows into the gutter.

Simulated lead flashings and closures

These range of trims are designed to simulate the look and feel of a lead roof.

Raised edge trims

Sold in 1.5 and 3 metre lengths, these up-stand trims are installed to contain and direct the flow of water into a gutter.

Wall fillet trim

Sold in 1.5 and 3 metre lengths, these angle fillet trims are fitted where the roof abuts a wall or vertical face, against parapet walls and in box gutters etc..

Expansion joints

Expansion joints allow for GRP roofs over 50m2 to cope with thermal expansion and contraction.

Angle trims

Angle trims are used when the GRP roofing laminate needs to cover a surface which continues perpendicular to the current level.

Application guide

Take extra care and use gloves when handling as the rough edges of the trim can be sharp. One side has been created with a high adhesion matt finish, which you must always bond to.

When cutting trims down to size always make sure that you are wearing a safety mask and never breath in any of the dust. Recommended tools for cutting the trims are hack saw, small angle grinder or multi tool. Another useful tool to cut trims are tin snips, these take much longer to cut than the others but they reduce the amount of dust being generated.

Bond the trims into position using polyurethane adhesive, you can either apply small beads at 300mm intervals or a small lines of adhesive under the fibreglass trim and then apply to the roof.

The trims can be fixed to the decking board using 15mm galvanised clout nails or staples with a compressed air gun. Simply hold the trim in position making sure the face is vertical, start by fixing the ends, then the middle and then 200mm thereafter.

When joining the trims together, simply overlap by at least 50mm applying a bead of PU adhesive to one of the surfaces. If a ladder is going to be leant against the trim for regular roof access or widow then you may want to either double up by slotting in an extra section of trim where the ladder would go or reinforcing with an extra layer of GRP laminate and then surface tissue to maintain the smooth finish.