Flat roofs on Lancing extensions, garages and outbuildings require specification appropriate to local conditions. We install GRP fibreglass and EPDM rubber flat roofing to a standard that lasts 30-40 years in this climate.
Adur flood plain humidity means felt underlay decay and timber batten rot run significantly faster than in elevated or sheltered locations. The flat roofs on Lancing's extensions, garages and outbuildings require the right material specification for local conditions. We install GRP as our first choice in exposed positions.
Low-lying coastal strip position means both sea exposure from the south and Adur flood plain humidity from the east. Some of the highest ambient moisture levels in West Sussex outside dedicated wetland areas. No elevation to deflect Channel weather — full south-westerly exposure at ground and roof level. Correct fall and drainage specification is critical in Lancing's rainfall pattern. We survey the existing structure, assess drainage routes, and specify falls that clear the roof surface within 24 hours of rainfall stopping.
We always strip to the deck before installation. Common findings on Lancing properties: saturated OSB or plywood deck from years of felt failure; joist rot from sustained moisture; inadequate insulation. We document all findings before quoting for extra work — never proceed without your agreement.
A GRP flat roof in Lancing requires minimal maintenance — an annual inspection and clearing of any debris from outlets. EPDM requires lap joint inspection every 2-3 years in West Sussex conditions. We carry out free annual inspections for all flat roofing customers for the first 5 years after installation.
| GRP fibreglass (per sqm installed) | £70 - £90 |
| EPDM rubber (per sqm installed) | £55 - £75 |
| Kitchen extension (20-25 sqm) | £1,400 - £2,250 |
| Garage (20-30 sqm) | £1,400 - £2,700 |
| Larger area (40-60 sqm) | £2,800 - £5,400 |
“Old felt roof on the extension had been leaking for two years. GRP installed in a day and a half. Looks completely different and I have no doubt it will outlast everything else on the property.”
“Replaced the garage felt with GRP. Quick, tidy and they found some deck rot I wasn't aware of — fixed it and showed me before proceeding. Honest job.”
“Third flat roof replacement in 30 years on the same extension. Went with GRP this time on their advice. Should be the last time I ever need to do it.”
1930s-50s bungalows on South Lancing beach strip, 1960s-70s estate housing in North Lancing, Adur flood plain position. Concrete interlocking tile on bungalow strip, aged 50-80 years. Flat garage and bungalow sections with felt at or past end of life on most properties..
Low-lying coastal strip between the South Downs and sea. Combined sea exposure from south and Adur flood plain humidity from east..
Adur flood plain humidity means felt underlay and timber batten decay runs significantly faster than in elevated or sheltered locations. Flat sections on bungalows consistently fail sooner than equivalent inland properties..
Pricing note: GRP flat roofing is particularly cost-effective in Lancing — the high ambient moisture makes felt lifespan even shorter than elsewhere in the region..
Every job follows the same clear process — no surprises, no hidden costs, full communication throughout.
We inspect the existing membrane, check drainage falls, assess the deck condition and identify any structural issues before quoting.
All existing felt or membrane stripped. Deck inspected thoroughly — any rot or saturation documented and quoted for before work proceeds.
Deck repaired or replaced where needed. Any drainage issues corrected. Falls assessed and improved where possible.
New membrane installed to manufacturer specification. GRP: full lamination across the entire deck as a single membrane. All upstands, outlets and penetrations correctly detailed.
10-year written workmanship guarantee issued. Free annual inspection for the first 5 years after installation.
GRP fibreglass is our recommendation for most Lancing properties. It forms a seamless, jointless membrane with no lap joints to fail, resists UV well, and has an expected life of 30-40 years. EPDM is suitable for sheltered positions. Traditional felt is not recommended for West Sussex conditions.
GRP fibreglass is £70-90 per sqm installed. A typical kitchen extension (20-25 sqm) costs £1,400-£2,250. A double garage (40 sqm) costs £2,800-£3,600. All prices include stripping the old felt and debris disposal.
GRP fibreglass correctly installed lasts 30-40 years in West Sussex conditions. EPDM lasts 20-30 years. Traditional felt lasts 8-12 years. The significant lifespan difference justifies the higher upfront cost of GRP for most customers.
Replacing a flat roof with the same material and specification is permitted development. Changing the roof type (e.g. adding a raised parapet or changing the drainage system significantly) may require planning approval. We advise on this during the free survey.
Yes — this is the most common flat roofing job we carry out. We strip all existing felt, inspect and repair the deck if needed, and install a GRP system directly over the existing structure in most cases.
10-year written workmanship guarantee on all GRP and EPDM installations. The GRP material itself carries a manufacturer guarantee of 25 years.
We cover Lancing and the surrounding area including Shoreham, Worthing, Hove. Call 01273 973 996 to arrange a free survey.
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