Signs a flat roof can be repaired
- The leak comes from one obvious split, blister or failed joint
- The surface is otherwise sound and firmly bonded
- The deck feels solid underfoot with no soft or spongy areas
- The problem is at an edge, upstand or flashing, not across the whole roof
Signs it needs replacing
- Leaks in several places, or leaks that return after patching
- Widespread cracking, blistering or bald patches
- Ponding water that never drains away
- A soft, sagging or bouncy deck, which means the boards are wet or rotten
Repairs by roof type
Felt roofs can be patched with new felt torched or bonded over the damaged area. EPDM rubber is repaired with primer and a compatible patch or tape. Fibreglass (GRP) cracks are ground back and re-laminated, then top-coated. The repair material must suit the roof, because the wrong product will not bond.
Why the deck decides it
A flat roof covering is only as good as the boards beneath it. If water has been getting in for a while, the deck and sometimes the insulation will be saturated. Covering over wet timber traps the moisture and the new surface fails early, so a roofer should check the deck before recommending a repair.
Getting an honest answer
Ask for photos of the damage and an explanation of why a repair will or will not last. A trustworthy roofer will offer a repair where one is viable and explain clearly when replacement is the better value.
