How to know whether to repair, patch or replace your roof

Replacing a roof can be expensive, so if damage can be dealt with by repairing or patching, that is the more cost-friendly solution.

Signs your roof may need a repair or patch

• Cracked, loose or missing roof tiles.
• Discolouration, moss or mould growth, which could indicate part of the roof is rotting.
• Sunlight visible from the loft, which could mean cracks or holes in the roof.
• Flashing separating from the roof. Flashing is the material around chimneys, vents and other protrusions; when loose it can let water into ceilings or walls.
• Damaged ridges, which are vital in keeping water out and can lead to damage across the whole roof.

These signs do not always mean a repair will do. Where damage has spread across a major section of the roof, a replacement is more likely to be needed. Ask a professional roofing company to assess the damage; repairs can often be simple but should always be carried out by a professional to avoid injury and further damage.

Signs your roof needs replacing

• Sagging: the ridge of a pitched roof should be a straight line. If it is not, there could be structural damage.
• Serious leaks when it rains or when snow sits on the roof.
• Objects that have fallen onto or through the roof and weakened its structure.
• Slate roofs: flaking or delamination, or powdering on the undersides of slates. Slates can often be turned and reused, but these signs mean the slate has deteriorated and become too porous.
• Concrete tile roofs: cement sediment building up in the gutters, a sign the tile surface has oxidised and is eroding.

A partial replacement is possible when damage is confined to one area. Even so, it is worth considering the whole job while scaffolding and equipment are on site, as it will usually cost less than doing one part now and the rest later.

We offer free, impartial advice on the most appropriate roof for your home, flat or pitched, and the best material for you.