★★★★★
“They came out the same day, found the problem straight away and had it fixed before the rain came back. Honest price and very tidy. Highly recommended.”
Formby
Flat Roofs — Crosby, L23
Flat Roofs in Crosby — Replacements and Repairs Done Properly
Crosby has a varied mix of properties and the flat roofing work we carry out across the L23 postcode reflects that variety. Garage roofs on 1960s and 70s properties, rear extensions on Victorian semis, bay window tops on period housing and the occasional larger flat-roofed section on more modern builds all present slightly different requirements, but they share a common problem: the original felt system installed on most of them is at or beyond the end of its serviceable life.
For new flat roof installations in Crosby we most commonly specify GRP fibreglass. The seamless nature of the system — the fact that it is a single poured membrane with no joints or seams — makes it inherently more reliable than traditional felt, which relies on overlapping layers and edge seals that are vulnerable to UV degradation and thermal movement over time. A well-installed GRP system on a Crosby garage or extension can be expected to last significantly longer than the felt it replaces.
Where a customer prefers EPDM rubber — or where the size of the roof or the specific thermal conditions make it the better choice — we install that instead. For straightforward repairs or lower-budget applications, torch-on felt remains a sound option. We carry the materials and equipment for all three systems and advise genuinely on which is most appropriate for each specific job.
Before any flat roof installation in Crosby we inspect the existing deck. Water ingress from a failing flat roof frequently causes deck board damage that is invisible from above, and installing a new membrane over a compromised deck produces a result that will fail prematurely. We find these issues before the job begins.
📞 Call for a free quoteAll flat roof systems installed
GRP fibreglass, EPDM rubber and torch-on felt — we carry and install all three and advise on the best choice for each job.
Deck assessment before quoting
We check the substrate before recommending a system. Hidden deck damage is the most common cause of premature flat roof failure.
Fast local response
Based in nearby Formby, we cover Crosby quickly for both repairs and new installations.
10-year written guarantee
Every flat roof installation is backed by our written guarantee.
Building Regulations
Building Regs, U-Values & Warm Roof Upgrades
Current Building Regulations (Approved Document L) target a flat roof U-value of around 0.16–0.18 W/m²K. A full replacement covering more than 50% of the roof typically triggers this requirement — which means most flat roof replacements are also a genuine opportunity to properly insulate the roof, often for the first time. We build every full replacement to a warm roof specification (insulation above the deck) as standard, since it's now the recommended approach and largely eliminates the condensation risk that older cold roof designs carry. See our complete guide to Building Regs and warm roof upgrades for the full detail.
Common questions
Flat Roofs — What People Ask
What flat roofing system lasts longest in Crosby?
GRP fibreglass and EPDM rubber both significantly outlast traditional bitumen felt when correctly installed. GRP is generally our preferred recommendation for garage roofs and smaller extensions; EPDM for larger areas.
My garage roof in Crosby is leaking — repair or replace?
It depends on the age and condition of the existing system and the deck below. We inspect before advising. If the deck is sound and the failure is localised, a repair may be the right answer. If the felt has reached the end of its life or the deck is damaged, replacement is more economical.
How is GRP fibreglass flat roofing installed?
GRP is installed as a two-coat system — a fibreglass matting layer bonded with resin, followed by a topcoat. The result is a single seamless membrane that is chemically bonded to the deck. It cures hard and can be walked on once set.
Do you replace flat roofs on outbuildings and garages as well as house extensions?
Yes. Garage roofs, outbuilding roofs, car port coverings — we install across all of these as well as house extensions and bay tops.
Does a flat roof replacement need to meet Building Regulations?
Yes, in most cases. A full replacement covering more than 50% of the roof is treated as a thermal element upgrade under Approved Document L, targeting a U-value of around 0.16-0.18 W/m²K. We build every full replacement to this standard, using warm roof construction, as a matter of course.