From failed felt on 1960s system-built extensions to modern GRP fibreglass installations — we deliver flat roofing solutions that last 25+ years across Basingstoke's diverse housing stock.
Basingstoke's overspill estates were built with thousands of flat-roofed extensions, garages and porches. The original bitumen felt on these structures has long since perished, and many have been through multiple re-felts that only delay the inevitable. We replace failed flat roofs with GRP fibreglass or EPDM rubber — seamless, maintenance-free systems with 25-year guarantees.
Related: EPDM vs GRP — Full Comparison →
Step one: strip the existing covering completely. We never overlay new material on old — it hides deck problems, adds weight, and voids manufacturer guarantees. Step two: inspect the timber deck for rot, delamination and adequate structural support. Any compromised sections are replaced with marine-grade plywood. Step three: create correct drainage falls using tapered insulation or firring strips — minimum 1:40 gradient so water reaches the outlet rather than ponding.
For GRP, we apply resin and glass fibre matting in controlled conditions, building a seamless shell bonded to every surface including upstands, edge trims and pipe penetrations. For EPDM, the rubber membrane is fully bonded to the prepared deck with all edges and terminations mechanically secured and sealed.
Correct drainage separates a flat roof that lasts 25 years from one that fails in five. We calculate required falls from the roof area and outlet position, then build the gradient into the deck rather than relying on the membrane to shed water across a level surface. On Basingstoke properties this matters because over a third of the housing stock dates from the 1960s–70s overspill expansion, so the same failures recur across entire streets.
GRP installations carry a 25-year manufacturer guarantee plus our 10-year workmanship guarantee. EPDM carries 20–25 years depending on the membrane specified. Both need minimal maintenance — clear the outlets twice a year and check the edges annually. We provide written aftercare guidance specific to your roof's design and your property's exposure to trees and debris.
Flat Roofing in Basingstoke: £800–£6,000. Free, no-obligation quotes. Call 0125 624 2410.
System-built properties across South Ham and Popley frequently have flat roof sections that were part of the original 1960s design. These are not bolt-on extensions — they are integral to the building structure, which makes proper waterproofing critical. We install GRP fibreglass with proper drainage falls calculated to Building Regulations, not just laid over the existing surface.
On newer properties across Chineham and Hatch Warren, flat-roofed rear extensions and garage roofs are common. We see a lot of poorly installed torch-on felt from previous contractors — bubbling, splitting at joints, and ponding water. Our GRP and EPDM installations eliminate all of these problems with a single seamless membrane.
Need a roofer in Basingstoke? Get your free quote today.
Call 0125 624 2410Four steps from first call to completed work. No call-out fee, no obligation, and a written quote before anything starts.
We inspect your Basingstoke flat roof — checking the membrane, deck condition, drainage falls, and detail work at upstands and edges. We recommend GRP or EPDM based on your specific requirements.
Your quote details: membrane system, deck replacement if needed, drainage fall calculation, edge trims, upstand detail, and guarantee. All materials specified by name.
Old covering stripped, deck inspected and repaired or replaced. New membrane installed with correct drainage falls, sealed upstands, and proper edge detail. Typically 1–3 days depending on size.
Completed flat roof inspected, drainage tested, and all detail work checked. You receive a 25-year manufacturer-backed guarantee and our 10-year workmanship guarantee.
Ready to start? Call 0125 624 2410 for your free survey.
"Had a GRP flat roof fitted on our rear extension in South Ham. The old felt was bubbling and leaking every winter. New roof is seamless — not a single issue since. Five stars."
"EPDM rubber roof on the garage — quick, clean, and half the price I was quoted elsewhere. Water runs off perfectly now instead of ponding in the middle. Great job."
"Flat roof over our kitchen extension was the original 1960s felt. They stripped it back, repaired the decking, and laid GRP with proper drainage falls. Bone dry ever since."
A single garage flat roof typically costs £800–£1,500. A rear extension flat roof is usually £1,500–£3,500 depending on size. Larger or more complex jobs can be up to £6,000. We provide free surveys and written quotes.
Both are excellent. GRP fibreglass is rigid, seamless and ideal for walkable surfaces and complex shapes. EPDM rubber is flexible, fast to install, and excellent for simple rectangular areas like garage roofs. We assess each job and recommend the best system for your specific property.
We can, but in most cases felt repair is a temporary fix. If your felt flat roof is over 15 years old — and many on Basingstoke's estates are 30+ years old — replacement with GRP or EPDM is more cost-effective over 5 years than repeated felt patches.
Not when installed correctly. The key is proper drainage falls — a minimum 1:40 gradient to prevent ponding. Basingstoke's moderate rainfall is easily managed by a properly specified flat roof. Problems only arise from poor installation or aged materials.
GRP handles normal foot traffic for maintenance access. EPDM is walkable but should not have heavy objects dragged across it. For regular terrace use we specify a reinforced non-slip topcoat.
Yes, and it is the most cost-effective moment to do it. Rigid boards above or below the deck improve thermal performance significantly, and combining the work avoids paying for the same job twice.
No call-out fees. No obligation. Just an honest quote from a local Basingstoke roofer who'll turn up when they say they will.
0125 624 2410