Flat Roof Specialists in North Wales.

Flat roofs along the north Wales coast face a tougher exposure than any other part of our area. The GRP fibreglass system dominates here because it bonds as a single continuous shell with no joints for salt-driven moisture to track through, and it handles the thermal cycling that the coastal exposure produces better than a seamed sheet system on smaller roofs. Properties from Rhyl through Prestatyn and Abergele that have flat-roofed extensions or garage roofs from the 1980s and 1990s are running on felt that has been worn hard by the sea air and is typically splitting at the laps. Inland at Mold and Buckley the flat-roof call is less common but still appears on 1970s bungalow extensions where the original felt has cracked through. All flat-roof work in North Wales falls under Welsh building regulations, and where the work is notifiable we file the notice with the local authority. The Chester Team covers all North Wales flat-roof calls.

Flat roofs are not inherently bad. A flat roof installed correctly with the right system for the deck type will outlast most pitched repairs on the same property. The problem is the stock of 1970s and 1980s felt-over-board flat roofs that are now failing across the mid-century estate housing belt from Ellesmere Port and Runcorn through to the Wirral south and into the Chester suburbs. That generation of felt is done.

We replace failing flat roofs with either Firestone EPDM rubber or CURE IT liquid glass GRP, depending on the deck condition and the roof geometry. Both carry independent BBA certification. Both are warrantied to 20 years. The choice is not arbitrary; it depends on the size and shape of the roof and whether any upstands, outlets or penetrations make a torch-on system a fire risk.

Materials we run

Firestone EPDM is our first choice on larger flat roofs with simple geometry. It goes down as a single bonded sheet, which means no seams across the field of the roof. The Firestone system has been BBA approved since 1993 and carries a 20-year product guarantee, with tested lifespans beyond 50 years in commercial applications.

CURE IT GRP (glass-reinforced polyester) is the call on smaller or more complex roofs where flashings, upstands and multiple outlets make sheet laying difficult. It goes down as a liquid, sets hard, and bonds directly to the deck. The CURE IT system is BBA certified and carries a 20-year material guarantee when applied by an approved contractor. We are an approved CURE IT applicator.

On the deck itself, if the existing boards have any delamination or softness, we board over with 18mm WBP plywood before laying either system. A flat roof system is only as good as the substrate under it.

When you need a flat roof replacement

If the existing felt is blistering, ponding water is pooling more than 25mm deep for more than 48 hours after rain, or you can feel the deck flex underfoot, the system has failed. Strip-and-recover is the correct answer. Patching failed felt with a torch-on patch buys time, not a solution.

Garage roofs, bay window tops, flat dormers and single-storey extensions are our most common flat-roof calls. All are straightforward one-day strip-and-recover jobs where the deck is sound.

What it costs

A typical single-garage flat roof replacement in EPDM runs between £900 and £1,400 plus VAT. A larger rear-extension flat of 30 to 50 square metres runs between £2,200 and £3,800. GRP on a complex geometry with multiple upstands and outlets adds 15 to 25% over EPDM on equivalent areas. We quote fixed-price after measuring.

What we back it with

Both EPDM and GRP installs come with a 10-year workmanship guarantee from Stockholms and a 20-year manufacturer material guarantee from Firestone or CURE IT respectively. The workmanship guarantee is insurance-backed through Q Assure.