Fire-Rated GRP Fibreglass Roofing Kit with Tools – BROOF(t4) Certified, 450g, 5m² to 30m²

Some flat roofs don't have the luxury of open space around them. An extension built tight against a boundary wall, a garage roof a metre from next door's fence, a commercial unit sharing a party wall — in all of these cases, Building Regulations Approved Document B can require the roof covering itself to carry a fire rating, not just the deck beneath it. This is the kit for that job: a complete 450g chopped-strand-mat GRP fibreglass roofing system built around a BROOF(t4)-rated resin and topcoat, supplied with every tool needed to lay it in one visit.

It installs exactly like our standard GRP kit — laminate the matting into the resin, roll out air bubbles, finish with two coats of topcoat — but the resin and topcoat formulation itself is fire-rated at the point of manufacture, so there's no separate fire-retardant layer to source or fit. One seamless, jointless, UV-stable surface with a 25+ year life expectancy when installed correctly, suitable for timber, OSB3 and plywood decking on sheds, garages, dormers, extensions and commercial flat roofs.

Key benefits

• Fire-rated to BROOF(t4) — the resin and topcoat carry the classification, not an add-on layer
• 450g chopped strand matting for a genuinely rigid, walkable laminate once cured
• Full tool kit included: laminating roller, brush, mixing stick — nothing extra to buy to get started
• One continuous seamless membrane — no joints, no seams to fail over time
• UV-stable topcoat, suitable for summer and winter installation
• 25+ year life expectancy when installed correctly to manufacturer guidance

Where it's used

Fire-rated GRP is specified wherever a flat roof sits close to a boundary, a neighbouring property, or falls under the fire-performance clauses of Building Regulations — garage roofs on boundary lines, dormer cheeks and flat tops near a party wall, commercial and mixed-use flat roofs, and any extension roof where a building control surveyor has asked for a rated covering. If your roof doesn't need a fire rating, our standard 450g GRP Fibreglass Roofing Kit covers the same sizes at a lower price point. Need a smaller size for a porch or bay window? Our 300g Fire-Rated GRP Kit covers 12m²–66m². Need a bigger commercial job above 30m², or already have your own tools? Our 600g Fire-Rated GRP Kit (materials only) covers 10m² up to 100m².

Specification

Ordering & installation guidance

Choose the kit size covering your total roof area — order slightly up rather than down if your roof falls between two sizes, since GRP is laid as one continuous laminate and can't be topped up mid-roof from a second kit without a visible joint. Deck should be sound, dry timber, OSB3 or plywood, minimum 18mm. For edge details, finish the perimeter with our GRP roof edge trim packs or GRP simulated lead flashing trim for wall abutments, both colour and profile-matched for a GRP roof. If the roof will see regular foot traffic, our EPDM walkway pads protect the finished surface without marking it.

FAQ

Do I need the fire-rated version, or will the standard kit do?
Check with your building control surveyor or Approved Document B if your roof is close to a boundary, on a terrace, or on a commercial/mixed-use building — fire rating is a site-specific requirement, not a universal one. If there's no boundary or fire-performance requirement, our standard 450g kit uses the same application process at a lower price.

What's actually included in the box?
The resin and topcoat for your chosen area, 450g chopped strand matting cut to size, a laminating roller, a finishing brush and a mixing stick — everything needed to laminate and topcoat the roof in one kit.

Can I lay this over an existing felt or asphalt roof?
No — GRP needs a sound timber, OSB3 or plywood deck. An existing felt/asphalt covering should be stripped back to a suitable board first.

How long before the roof can be walked on?
The topcoat is typically tack-free within a few hours in good conditions, but always follow the cure guidance included with your kit before allowing regular foot traffic — our walkway pads are recommended for any roof that sees ongoing access.

What's the delivery time?
Kits are dispatched from UK stock — check the product page at checkout for the current delivery estimate to your postcode.