The short answer
Maintain a pitched tiled roof by checking it from outside and from the loft each spring and autumn, and after any storm. Look for slipped or cracked tiles, clear gutters and valleys, watch the ridge and lead flashings, and check the loft for damp or daylight. Work at height, such as lead, ridge bedding and replacing tiles, belongs with a roofer.
What you can check without a ladder
The best first inspection costs nothing and keeps your feet on the ground. Stand back far enough to take in each slope whole, with binoculars if you own a pair. A tiled roof should look even, with straight courses, a ridge that runs level and no tiles sitting proud or dropped below their neighbours.
On each slope, look for the following.
- Slipped tiles. A tile that has moved down leaves a dark gap or a ragged edge in the course.
- Broken or missing tiles. Shards lying on the drive or caught in the downpipe shoe can give the game away before you see the gap.
- A wavy line. A dip along a course can point to tired battens, the thin timbers that carry every tile.
- Ridge and hip lines. Cracked or crumbling mortar, or a ridge tile that has shifted, needs a roofer.
- Moss in thick clumps. A light film does little harm, but deep cushions hold water against the tile.
- Stains on walls. A damp mark under the eaves or around a chimney suggests a gutter or flashing fault higher up.
Do it in spring and again in autumn, and also after a bad storm. Write down what you see, or take a photo of each slope, so you can compare it next time. Change over time is often easier to spot than a fault on its own.
Stay off the slope itself for a closer look. Tiles crack underfoot, and a fall from a pitched roof is a serious injury. If something needs a closer view, that is what a survey is for.
Gutters, valleys and the water path
Water is what shortens the life of a tiled roof, so keep its route clear. A gutter that overflows sends rain behind the fascia and into the eaves, where the rafter ends and the first batten sit. On an older roof that is a common place for rot to begin.
Scoop leaves, silt and moss out of the gutters at least once a year, with a second visit after leaf fall if trees overhang. Check that gutters slope toward the outlet and that joints are not dripping. A damp stripe on the wall below a joint tells you it has failed.
A valley is the sloping trough formed where two roof planes run into each other. It handles a great deal of runoff and it traps debris. A window upstairs often gives a safe view of whether it runs clear. If it clogs, water can back up beneath the tiles beside it, which is why a roofer looks there early.
A downpipe that runs over a wall or a hopper head that spills needs dealing with promptly. Wet ground at the foot of a wall suggests the whole route from roof to drain is struggling.
Checking from inside the loft
The loft tells you what the roof is doing, because a tiled roof that leaks does so on the underside first. Go up on a bright day with a torch and look at the following.
- Daylight. Pinpoints of light through the slope mean a tile is missing or cracked. A bright line along the ridge can mean the bedding has failed.
- Damp or dark patches on timber. Rafters and battens that are dark, soft or stained have been wet. Press a dry screwdriver tip into the timber. If it sinks in easily, the wood is soft.
- Underlay. Underlay is the membrane stretched under the battens, there for rain that gets driven up past the laps. Tears, brittle edges or sagging pockets that hold water need attention. Our page on sagging roof felt explains when drooping matters.
- Condensation. Beads of water under the slope, or mould on the timbers, usually mean moist household air is rising into the cold roof space.
- Insulation. Wet or flattened insulation under a suspected leak tells you where the water comes in.
Do not step between the joists onto the ceiling below. Use boards across the joists, or look from the hatch with a good torch.
Ridge, hips, verges and lead
These are the parts of a tiled roof that age fastest, because they hold fixings, mortar and metal rather than just tile.
The ridge is the apex of the roof, capped with ridge tiles that are either bedded in mortar or fixed dry. The verge is the outer edge of the covering over a gable wall. Mortar cracks as it weathers, and BS 5534:2014 says it cannot be relied upon by itself to hold those tiles, so a modern repair adds mechanical fixings. Dry-fix systems, covered by BS 8612:2018, use clips and screws instead of a wet bed.
Flashing is the lead strip tucked into the joint where a slope meets a chimney or wall, shaped so rain runs over the joint instead of into it. It can lift in wind, split with age or be stolen, and a small gap there lets water into a spot that is hard to dry. From the ground, look for lead that has lifted, slipped out of its chase, or been covered in a thick black sealant. Sealant over lead is usually a sign of a repair that has not lasted.
Chimney stacks deserve a look too. Crumbling mortar joints, a leaning pot and a gap between the stack and the roof all call for work. We replace failed flashing and the surrounding leadwork as part of the roof repair, not as an afterthought. All of this is work at height, and it is better done by a roofer with proper access.
Moss, algae and cleaning
Moss settles on slopes that stay damp, typically shaded ones. A film of algae is cosmetic. Thick moss is different, because it holds moisture against the tile, lifts edges and fills the gaps between courses. In winter, trapped water freezes and can break the surface of a tile.
Removing it needs care. MyBuilder's 2026 cleaning guide notes that pressure washing "may damage delicate tiles", and the jet can push water upward beneath the laps and scour the surface of concrete tiles. Soft washing with a biocide, or hand brushing, is gentler. Never scrape moss off with a hard tool, and never work from a ladder against the gutter.
Typical UK ranges reported by MyBuilder for roof cleaning are £450 to £850 for a pitched roof and £400 to £750 for a tile roof. Those are national figures. Your fixed price follows the survey.
Cleaning is cosmetic unless it reveals a fault, so it is worth having a roofer check the tiles as they are cleaned. If you see tiles that crumble or flake, the roof may be reaching the end of its life, and washing will not change that.
Calling a roofer, and what a visit covers
Ring a roofer for slipped or missing tiles, a dip in the roof line, lifted lead, a cracked ridge or any leak. If water is coming in, do not wait for a dry spell. Leaks and storm damage jump our queue, and our first job is to make the roof watertight again.
A thorough inspection takes in the covering, ridge, hips, verges, valleys, flashings, stacks, gutters and loft timbers together. Our free survey includes pictures of your own slopes, so you see the same faults we do, and a fixed written price follows.
Many faults on a tiled roof are repairs, not renewals. A few slipped tiles, a failed flashing or a cracked ridge can be put right without touching the rest. Where repair works, we repair. Where the battens, underlay and fixings have failed across the whole roof, patching has run its course, and the next step is a strip and re-lay. Our re-felting cost page explains what that involves, and our guide to roofs without felt covers older roofs with no underlay at all.
For a wider look at the whole subject, start with the pitched roofing service page.
