GRP Roofing Trims are an essential part of the GRP / Fibreglass flat roofing process. Not only do the trims add a professional finish, but they are essential for aiding drainage. With so many roofing trim options to choose from, we are often contacted by customers with lots of questions on how to choose the right types. This article will help ensure you select the right ones!

Choosing the correct GRP Roofing Trims

Each roofing trim has a different purpose, shape and fit. A combination of several trims may be required depending on the size and shape of your fibreglass roof.

Drip Roofing Trims

Drip Roofing Trims are one of the most popular types of GRP Roofing Trims on the market. They are used at the lowest point of the roof and fitted to the edge of the roof which allows drainage into the gutter.

The most popular examples of Drip Roofing Trims are the A200 and the A250. The A200 is compatible with the B260 upstand and the A250 is suitable for use with the B300, C1, C2 and C4 corners. Both the A200 and A250 are available in 1.5 and 3 metre lengths.

Drip Trim Installation

Raised Edge Trims

Raised Edge Roofing Trims or ‘B’ Roofing Trims are used to keep water on the roof whilst directing it to the lowest point. This can be an outlet or a drip.

The B260 and B300 Roofing Trims are both Raised Edge Trims. The B300 is compatible with the A250 (as mentioned above), C1, C2 and C4 corners. The B260 can be used can be used with the A200. These roofing trims are available in both 1.5 metre and 3 metre lengths.

Wall Fillets

The wall fillet GRP Roofing Trims are used where the fibreglass flat roof butts again an existing wall to create a 45-degree angle which will redirect rainwater from the wall to the roof. It is also suitable for gutter lining. If required, the Wall Fillet trims can provide expansion and ventilation on the perimeter of the roof.

The D260 Wall Fillet Trim can be purchased from FibreGlassDirect in 1.5 metre and 3 metre lengths.

Internal and External Trims

The AT195 Internal and AT195 External are the internal / external trims provided by FibreGlassDirect.

The AT195 Internal trim is used wherever the laminate needs to cover an area which continues perpendicular to another laminated surface. The AT195 External Trim is supplied with a high-adhesion finish on its outer fascia and is mainly used for capping applications.

Flat Flashings

The F trim is a flat flashing, mainly used at the intersection of a pitched roof and flat roofs often found on dormers. The F trim should not be laminated over completely as it will crack.

The F300 Flat Flashing GRP Roofing Trim is available in a 1 metre length.

Soffit Trims

This over-sized soffit trim, the S500 Trim, is used to encapsulate the edge profile of a concrete or similar construction deck. A wooden support batten is nailed to the wall underneath the roof structure.

Corner Trims

Corner GRP Roofing Trims will provide strength and reinforcement to corner segments of your fibreglass roof.

There are a variety of left handed, right handed and universal corners depending on the corresponding trim used.

Simulated Lead Flashing

Simulated Lead Flashing GRP Trims will give the appearance of lead. These roofing trims are not top coated.

Expansion Joints

Expansion GRP Joints are used on larger areas to create an expansion joint. It can also be used to create a ridge detail on the roof if required.

Rolled Rib Closures

Rolled Rib Closure Roofing Trims are designed to simulate the appearance of a raised rolled lead seam. It can also be used as an expansion trim on large roofs.

The ER35/40 Rolled Rib Roofing Trim is available from FibreGlassDirect in either a 1.5 metre or 3 metre length.

Application of GRP Roofing Trims

Once the initial structure of the roof has been laid (or in the case of a fibreglass roof repair, stripped back) using OSB3 roofing boards – it is time to apply the GRP Trims.

Roof trims should be measured and cut to size with some snips (to reduce dust).  Roofing adhesive should then be applied to the batons to prevent rattling in the wind.

To secure the Roofing Trims, 15mm clout nails should be nailed or using a staple gun, stainless steel stapled into place every 120-150mm. In some cases, two trims have to be joined together. In this instance, ensure an overlap of 50mm is adhered to and apply roofing adhesive to seal.

Buy GRP Roofing Trims from FibreGlassDirect

FibreGlassDirect is an established and trusted supplier of GRP Roofing Trims. We have supplied GRP Roofing Products throughout the UK and Ireland for over 30 years.

To complement our GRP Roofing Trims, we offer a comprehensive range of GRP Roofing Kits which are supplied with a choice of fire retardant or standard roofing topcoat, chopped strand matting and tools. Our GRP Roofing Kits are available up to 100sqm.

For further information or to buy any of our products, visit our GRP Roofing Materials section.