HOW TO FIX EDGE TRIMS FOR A FIBREGLASS ROOF INSTALLATION

July 27, 2018

RKD understand that fixing GRP trims is perhaps the first and most straightforward element of installing a fibreglass roof. This of course assumes that your decking, which is preferably 18mm OSB has been laid.

 

For the first time installer or DIY enthusiast please ensure that you fix the trims to the deck with ring shank/clout/felt nails. Screws have a tendency to split the trim. You can also use PU adhesive where you think expansion needs to be considered. Ensure your nails are completely flat to the trim.

 

Pictures paint a thousand words, so below are simple diagrams of how to fix our most popular trims. Our diagrams show all trims with and where bandaging is applied.

 

The Wall Fillet trim -
used to create a waterproof upstand against a wall or upstand (Fits over the 25mm gap between decking and wall) The trim is nailed to th deck only (not the Brickwork)

 

The Flashing trim - fits over the wall fillet trim and slotted and bonded into a chase groove in the wall and fixed with silicon adhesive. (it is not fixed to the fillet trim)

 

The Drip trim -
 used at the roofs lowest point directing the water into the gutter. The trim is nailed to the deck, bandaged and a bead of PU adhesive run along the edging batten.

The Raised Edge trim - used to prevent water dripping off the roof edges and guides water flow to the gutter edge. Nailed to the deck, bandaged and overlapped by CSM.

 

 

The Flat Flashing trim - used where the flat roof adjoins a sloping tiled or slated roof. Nailed to the deck and run under the roof membrane.

 The Expansion trim - used on fibreglass roofs greater than 50sqm. The trim is nailed to the deck, bandaged and the CSM run continuously over the trim.

The internal Gutter trim (specialist) - used where internal roof drainage is required. The trim is nailed to the decking and bandaged with the matting run continuously over the gutter.

 

The external and internal right angle AT 195 trims (specialist) - used where upstands or roof lights/lanterns are present.

Cutting trims - RKD recommend that you invest in a good pair of snips. Old tech but they work well -You can also use a hacksaw or grinder but remember that here dust will arise - a mask is mandatory.

 

Joining trims - simply overlap by 50 - 75mm applying a bead of PU adhesive between the trim surfaces. Using a small amount of manual persuasion they will clip together nicely.