Small local defects can sometimes be repaired, but widespread cracking, loose felt or a damaged roof deck is normally a refelting job. Start by finding out whether the problem is only in the covering or in the timber underneath.
A small puncture or local tear can be patched if the surrounding felt is sound
Clean and dry the area, remove loose material and use a compatible bituminous repair product or properly lapped felt patch suited to the existing covering. Black Jack 903 Bitumen Trowel Mastic is the repair product in our range for cracks, holes and defects in compatible traditional roofing materials.
A lifted lap needs rebonding before wind makes it worse
If the felt itself is still sound, clean beneath the loose area and use a compatible felt adhesive such as Black Jack 904 where appropriate. Press the lap back into full contact and follow the adhesive manufacturer's curing instructions.
Do not cover rotten or badly swollen roof boards
If water has damaged the OSB, plywood or timber deck, repair or replace the deck first. Covering soft or failed boards only hides the structural problem.
Refelt the roof when the damage is widespread
Multiple tears, brittle felt, extensive lifting, failed edges or repeated leaks usually make a complete replacement more sensible than a collection of patches.
For replacement material, shop Roofing Felt & Shed Felt and follow How to Felt a Shed Roof. For liquid repair systems and mastics, see Roof Sealants & Repair Coatings.
