Roof leaks to your roof

A roof leak rarely fixes itself — and the longer water gets in, the more it costs to put right.

What causes a roof leak?

Most leaks come from a small number of failure points: cracked, slipped or missing tiles and slates; failed flashing around chimneys, abutments and valleys; a worn or split underlay (the felt beneath the covering); blocked or overflowing gutters forcing water back under the eaves; and degraded mortar on ridges and verges. On flat roofs, splits, blisters and failed seams in the membrane are the usual culprits.

Signs you have a leak

Brown or yellow staining on ceilings or upstairs walls, damp or musty smells in bedrooms, dripping in the loft during or after rain, and visible daylight or wet timbers when you look in the loft. Don't wait for a drip — staining usually means water has already been getting in for a while.

Repair or replace?

A single, isolated leak on an otherwise sound roof is usually a repair. But recurring leaks, leaks in several places at once, or a leak combined with a roof that's already near the end of its life often mean the underlay has failed — and that points to a re-roof rather than endless patching. A roofer's inspection will tell you which.