What If Broken Tiles Are Found During a Roof Clean?

Moss and thick algae cover a roof like a blanket. They fill small cracks, sit over chipped corners and hide tiles that have shifted a few millimetres. Until the growth is brushed or rinsed off, an owner and a roofer looking from the ground see only a green surface.

Once it is cleared, the roof shows its real condition. Hairline cracks across a tile, broken corners, tiles with snapped nibs that have slid out of line, lifted ridge tiles and perished pointing along a verge all appear. Frost damage shows too, as flaking or crumbling on porous tiles. None of this means the clean caused the damage. It was there before, and often explains a stain or drip you had already noticed.

Walking on tiles to do the work can also break a few, which is why a careful roofer treats the roof with respect, uses roof ladders or boards where they help and checks the finished surface. Whatever the cause, the right response is the same: record what is found, explain what it means for the roof, and agree the next step. Our guide on manual moss removal from a roof describes how the work is carried out.

If a roofer is already on the roof with ladders or scaffold in place, repairing a few tiles in the same visit is both sensible and kinder to your budget. Another visit would mean putting up access again, and access is often the larger part of a small repair. Replacing a single tile follows the pattern in our answer on replacing individual roof tiles: lift the tiles above, slide the broken one out, check the batten, fit and fix the new one.

The sequence matters. A cleaner who spots a cracked tile should flag it before the treatment is applied, because a cracked tile lets the product and water through. The tile is swapped first, then the surface is treated. The roofer should also look under it for a wet batten or torn underlay, since a tile may have cracked because of a problem beneath.

Some damage is not a quick swap. Cracked mortar along a ridge or valley, a rotten batten or a failing flashing is a bigger job, and may need its own survey and price. Doing a cheap patch on a larger fault only hides it for a season.

You should not be asked to take a roofer's word for it from a ladder. Photos of each damaged tile and of the surrounding area let you see the same thing the roofer sees. Ask for them before agreeing to extra work, and ask what happens if nothing is done: whether the fault will worsen, let water in or put other tiles at risk.

On the price, the check is simple. Is the repair included in the original total, or quoted separately? Does the figure include VAT? As a national guide, Checkatrade's October 2026 tile replacement table gives £170 to £500 for up to five slipped or broken tiles, covering simple work, ladder access with bedding, and jobs needing scaffold. That is a yardstick; the price for your roof depends on what the survey finds.

Our approach is to survey first, share the photos of what is found, and give one written total. If more turns up during the clean, we stop, show you, and agree the change in writing before we do the work. Our answer on roof cleaning and moss removal sets out the sequence.

A few cracked tiles on an otherwise sound roof are normal wear. A scatter of them across one slope is different. If many tiles are cracking, the covering may be near the end of its life, and cleaning it only improves its look. Tiles that crumble when lifted, flake in layers or show damp patches beneath point the same way.

Check whether the cracked tiles are clustered. Breakage along the eaves may point to frost and sitting water, while breakage along a valley can point to overflow. Tiles broken near a chimney may reflect a failed flashing. Tiles slipping out of line may need the nib and batten checks described in our answer on broken tile nibs and the wider look at cracked roof tile repair.

If the survey shows widespread decay, the honest advice is to stop spending on cleaning and consider a repair plan or a re-roof. A clean on a failing roof gets the cost back in neither looks nor leak protection. To start, send us photos of the cleaned roof from the ground and any tiles you have found in the garden or gutter. We check those first and tell you what each means.