Resin application

How to apply the GRP Roofing base resin system

Resin guide

As per our fibreglassing guide we recommend that you should use either 1 layer of 600gm or 2 layers of 450gm fibreglass matting, for this example we will be using 1 layer of 600gm fibreglass matting. If you allow for 2.5 litres of Fibrelast base per square metre, this should give you an excellent pin hole free coverage.

1 layer 600gm

Use 2.5 litres per m²

2 Layers 450gm

On each layer use 2 litres of resin per m²


Laminating is a term that describes the application of catalysed resin to the fibreglass matting. Start off by mixing a small amount of resin to laminate any details like pipework and trim overlaps. Laminate the fibreglass bandage around the trim to deck joints along with the decking joints if you haven't used a T&G board.

First, using a resin application roller, generously apply a catalysed base resin mix to the OSB decking on an area no greater than 3 m2

Then place the pre-cut fibreglass reinforcement over the saturated area, applying more catalysed resin over the top of the fibreglass.

Allow the fibreglass and resin mix to activate and start breaking down the binder in the fibreglass matting before working the base resin mix through the fibreglass with a consolidating roller.