In detail
What determines the right flat roof repair?
The most useful recommendation connects the visible defect with the material, supporting layers and route rainwater should take.
Felt repairs and layered waterproofing
Felt roofing relies on a correctly formed waterproof assembly, with particular attention to laps, edges and upstands. Weathering, movement or damaged details can interrupt that assembly. A repair needs sufficient sound material around the defect to form a suitable connection, rather than simply covering the visible split with whatever product is available.
Landmark Roofing Solutions specialises in three-layer felt systems. That knowledge is relevant when assessing existing felt roofs, but it does not make every old covering repairable. Brittle surfaces, repeated patching or deterioration beneath the felt may limit the usefulness of another local intervention. The recommendation should explain those limitations clearly.
EPDM and GRP require different approaches
EPDM is a flexible rubber membrane, while GRP forms a rigid fibreglass covering. Their repair methods are not interchangeable. Surface preparation, compatible materials and the condition around seams or trims influence the result. A defect near a roof edge may require a different solution from a puncture in an otherwise sound central area.
Movement and substrate condition also matter. Cracking in a GRP surface can be associated with the detail beneath it, while an EPDM leak may involve a junction rather than the main sheet. The assessment should therefore establish what has failed and why, instead of choosing a repair solely from the name of the covering.
Ponding, outlets and the supporting deck
A flat roof is normally designed to shed water towards drainage points rather than retain it indefinitely. Leaves and debris can obstruct outlets, but some roofs also have low areas caused by inadequate falls or deck movement. The distinction matters because removing debris and rebuilding a deficient section are very different scopes of work.
Persistent moisture can affect timber components beneath the covering. Where decay or softness is suspected, a waterproof patch is not a structural repair. Safe inspection and, where appropriate, opening-up help establish the condition. Do not test a suspect roof by walking across it: a weakened deck may not support your weight.
When an overlay is not the answer
An overlay can only be considered where the existing roof is suitable to receive it. Moisture, adhesion, deck condition, detailing and the proposed build-up all need assessment. Adding another layer without resolving those questions can conceal deterioration and leave inadequate junctions or drainage arrangements in place beneath a new-looking surface.
Replacement may be more appropriate where the covering and supporting materials have reached the end of useful service or defects are widespread. A supplied customer account describes a flat roof leaking in different places before renewal was chosen. That illustrates why repeated leaks deserve investigation; it does not mean every leaking flat roof needs replacement.

