Flat Roofs · York & Yorkshire
A flat roof isn't 'flat', it's a carefully specified drainage system. We install the right membrane for the span, exposure and traffic, so extensions, garages and dormers stay watertight for 25 to 50 years.
30+
Years trading
20+
Yrs owner experience
10
Employed roofers
2 hr
Emergency response
10 yr
Workmanship guarantee
What we do
A flat roof installation covers the removal of the failing covering, replacement of any rotten deck, upgrade of insulation to current Building Regs, and installation of a modern single-ply, liquid or fibreglass membrane. Detailed correctly at upstands, outlets and flashings, a modern flat roof outlasts every three-layer felt roof of the 1980s combined.
Homeowners with a leaking single-storey extension, garage owners tired of an annual bitumen patch, and developers finishing a modern dormer. Anyone whose flat roof was fitted in the last century and is now on its second or third repair.
Ponding water that never dries, blistering on the surface, splits at joints, moss growth or a persistent damp patch on the ceiling below. A pool table's worth of ponding is a warning; a room's worth is a bill.
A flat roof is either right or it's leaking. There isn't a middle. Falls, upstands, laps and terminations are what make it last, and they're specified once, on installation, or paid for in maintenance forever.
What happens if it's ignored
A roof issue left alone compounds quickly. Water tracks, timber rots, and repair scope escalates by season. Here's what we see when a customer waits.
Traditional pour-and-roll felt lasts 10–15 years at best. Once the top cap blisters and splits, water sits on the deck and rots it out, turning a covering job into a whole re-boarding.
Any flat roof needs a minimum 1:80 finished fall. Roofs built to zero fall pond permanently, doubling the load on the membrane and accelerating failure at every seam.
Cheap GRP fibreglass without a properly conditioned deck and a full base coat cracks under thermal cycling, usually where two boards meet. Once it's split, no topcoat rescues it.
Most flat roof leaks come from the edges, not the middle. Undersized upstands, unfinished drips and cold outlets are where water finds its way in, and where cheap installers cut the most corners.
Our process
We probe for wet insulation and rotten deck, measure the falls, photograph the upstands and outlets, and confirm the substrate before we quote.
A written recommendation with a written fixed-price quote within 6 hours. EPDM, GRP or liquid, the right choice for your span, exposure, foot traffic and budget, not what's in the van.
We strip the old covering to the deck, replace any wet or soft boarding, and lay new insulation to modern U-values with a vapour control layer where needed.
Membrane laid to manufacturer detail, bonded, mechanically fixed or fully adhered depending on system, with fully welded seams and correctly formed upstands, drips and outlets.
We water-test outlets and check every seam and detail, then issue the 10-year written workmanship guarantee plus the manufacturer product warranty (typically 15–25 years).
Why homeowners pick us
Modern EPDM and liquid membranes on a correctly detailed roof routinely reach 25+ years. Fibreglass installed on a conditioned deck reaches 30+.
We install EPDM, GRP fibreglass, torch-on felt and cold-applied liquid, and specify the right one for your building, not the cheapest one for us.
Free survey, written fixed-price quote, no 'from' figures, no day-rate creep once the deck is opened up.
Our 10-year written workmanship guarantee in writing, on top of the manufacturer product warranty (15–25 years depending on system).
A typical single-storey extension or garage roof is stripped, insulated and finished inside a working week.
Where fire risk is a concern, adjacent property, tight terraces, we install cold-applied liquid or EPDM instead of hot-work systems.
The detail
The right flat roof system depends on the substrate, the falls, the exposure, the traffic and the budget. Below is a summary of the systems we fit and how we choose between them.
A single-sheet synthetic rubber, typically installed in one piece on domestic extensions and garages. Excellent for cold-applied installation, no hot works, and a 20–25 year manufacturer warranty is standard. Best for straightforward geometries with limited penetrations.
A liquid-applied glass-reinforced polyester system laid in three coats over conditioned OSB3 board. Extremely tough, walkable, and forms a seamless finish around outlets and upstands. Best for balcony roofs, roof terraces and complex shapes with multiple penetrations.
Modern SBS-modified bitumen membranes are a world away from the 1980s pour-and-roll. Laid in two layers with a mineral-finished cap sheet, they carry 20-year warranties and remain the most cost-effective large-area system for warehouses and utility roofs.
Cold-applied polyurethane and hybrid liquids are ideal for retrofits over failing existing roofs, awkward geometries, and buildings where hot works aren't safe. Fully reinforced with fleece, they behave as a single continuous membrane once cured.
Any new flat roof triggering more than 25% coverage of a roof plane needs a Part L thermal upgrade. We build warm-roof systems with rigid PIR insulation and a vapour control layer as standard, sitting the insulation above the structural deck to avoid interstitial condensation.
Every flat roof stands or falls on its details. We spec: minimum 150mm upstands at all abutments, GRP or lead-lined drip edges over gutters, sump outlets with pre-formed collars, and formed corners rather than mitred cuts. It's these details, not the membrane brand, that separate a 10-year roof from a 30-year one.
FAQ
On a straightforward domestic extension, EPDM and modern SBS felt both reach 20–25 years, GRP reaches 30+ where properly installed. Detailing at edges matters more than brand.
Domestic replacements typically sit between £110–£180/m² fully installed, including strip-out, insulation upgrade and new membrane. Every quote is fixed in writing after survey.
A typical single-storey extension takes 2–5 working days depending on size and any deck replacement. Larger commercial installations phase to your trading pattern.
Sometimes, using a liquid overlay system, but only when the existing structure is sound and dry. Overlaying wet insulation shortens the new roof's life dramatically, we survey and tell you honestly.
A correctly built flat roof has a minimum 1:80 finished fall and clears within hours of rainfall stopping. Where the existing structure is dead-level we build up new falls with tapered insulation.
GRP is designed to be walked on. EPDM and felt can take occasional foot traffic but shouldn't be a walkway, we can install walk-boards or a paved terrace zone where you need proper access.
Any replacement covering more than 25% of the roof triggers a Part L thermal upgrade. We handle the notification and the U-value upgrade as part of the quote.
10-year written workmanship guarantee from us, plus the manufacturer product warranty on the membrane, typically 15 years for felt, 20 for EPDM, 25 for premium GRP systems.
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Ready when you are
Free survey. Written quote back within 6 hours. 10-year workmanship guarantee. No call-out fee, no pushy follow-ups.
