Flat Roofing Worthing

GRP Flat Roofing — The Detail Behind the Job

Why GRP Is the Only Sensible Flat Roof Choice in Worthing

Worthing's coastal environment shortens felt flat roof lifespans significantly compared to inland properties. Salt air attacks the bitumen surface of felt, causing surface crazing and loss of mineral aggregate. UV exposure on south-facing flat roofs — more intense on the south coast than inland — accelerates embrittlement. The combination typically reduces felt lifespan to 8–12 years on Worthing properties, compared to 15–20 years inland. GRP fibreglass is completely impervious to salt air and UV degradation. It has no joints or seams — the primary failure mode of felt systems — and requires no maintenance. On a Worthing coastal property, GRP pays for its premium over felt within 10–15 years through eliminated replacement cycles.

Deck Assessment — What We Find Under Old Felt in Worthing

Before any flat roofing job in Worthing, we assess the structural deck — the plywood or OSB boarding beneath the existing covering. On properties where felt has been failing for some time, deck delamination and rot are common. We find rotten decks on roughly 40% of Worthing flat roofing jobs where the original felt is over 15 years old and has been tracking water. A rotten deck must be replaced before GRP is applied — overlaying GRP on to compromised boarding traps moisture and the deck fails beneath the new membrane. We assess, report and quote the correct scope before work begins.

Drainage Design for Worthing Flat Roofs

Correct fall is as critical as the membrane. Worthing receives approximately 780mm of rainfall annually, with heavy autumn and winter events common from Atlantic systems arriving from the south-west. A flat roof with inadequate fall ponds water — and standing water eventually finds a way through any system. We set a minimum 1:80 fall on all Worthing flat roofs, with outlet positions designed to handle peak rainfall without backing up. On near-seafront and Adur-valley properties with above-average wind-driven rain, we increase upstand heights to 200mm minimum at all perimeter and abutment edges.