Use this to understand what age does to a concrete tile face, how to compare cleaning methods before you accept a quote, and how typical tile life helps you decide between a clean and a re-cover.
Concrete tiles are a hard-wearing covering that has been laid on British houses for many decades. They are also porous, and over the years they gather growth: moss in the lap joints, patches of lichen and dark algae streaks on slopes that stay damp. A concrete roof that was crisp and even in colour when it was laid can look patchy and tired long before it is worn out.
Cleaning one is not the same job as cleaning slate or clay. A concrete tile is made from sand and cement, often with a coloured surface layer, and the face of an older tile has had decades of rain, frost and sun working on it. Treat it too roughly and you take away more than the moss.
This guide covers what surface wear looks like on older concrete tiles, the gentle methods that suit them, how long concrete tiles are said to last and how to judge whether a clean is a good use of money. It forms part of our roof cleaning and moss removal service, which begins with a look at the tiles and not with a method.
What age does to a concrete tile face
A new concrete tile has a smooth, even face. Over the years the weather removes some of that finish, and the tile becomes rougher and more absorbent. That rougher face holds water for longer and gives moss and algae a better grip.
What you can see from the ground, or in photos taken with a long lens, tells you about the state of the surface:
- Fading, where the coloured layer has thinned and the grey of the body shows through.
- A sandy or gritty feel on a tile lifted at the survey, and sand collecting in the gutter.
- Dark streaks that have worked into the face and do not wash off easily.
- Edges that have rounded or chipped, especially along the lower edge of the tile.
- Hairline cracks, seen best when the tile is wet.
Surface wear is not the same as failure. A tile can look dull and still keep out the weather for many years. The point of looking at the surface is to choose a cleaning method that does not strip what is left, and to know before the work whether the tile will come up well.
Moss is a separate thing, and a heavier one. It grows in the laps, lifts the edge of the tile above and holds water in the joints. Our page on how often a roof should be cleaned sets out why a roof needs attention when growth returns.
How long concrete tiles last, as context for cleaning
HomeBuilding gives a typical life of 40 to 50 years for plain concrete tiles and for Double Roman concrete tiles. Marley adds that its own figure for concrete tile is not a guarantee or warranty of its longevity. Those are typical ranges. A particular roof can fall short of them or go beyond them, depending on exposure, how it was fitted and how it has been looked after.
The range matters because it helps frame the question of whether to clean. The spend on a clean makes more sense on a roof in the earlier or middle part of that life than on one at the far end:
| Roof state | Cleaning sense |
|---|---|
| Sound, dark with growth | A clean is reasonable |
| Sound but worn face | Clean gently, consider a coating |
| Cracking, many slipped tiles | Repair or re-cover first |
Age alone does not settle it. Many roofs are old yet sound, and a younger roof can have problems from poor fixing. A survey from the roof tells more than the date on the house.
If you do not know how old the tiles are, say so at the survey. The builder's name, the date of the house or the last known roof work can help.
A clean does not add to the life of the tile on its own. It removes growth that holds moisture and shows the real condition, so that any repair can be decided on sound information.
Gentle methods that suit older concrete tiles
The principle is to take off the growth and leave the face. For older concrete that usually means starting by hand and moving on only if needed, and keeping any water at low pressure.
- Hand brushing and scraping removes the bulk of the moss from the laps and the tile edges, working down the slope so that loosened moss does not wedge under the tile above.
- A gentle rinse with a cleaning solution, kept at low pressure, lifts algae and lichen from the face and carries the debris towards the gutter.
- A biocide treatment kills what remains and lets it release over the following weeks, with no scrubbing of the surface at all.
Which of these suits a roof depends on what is growing there. Heavy moss needs the brush first. Algae and lichen respond to a treatment better than to scrubbing. A mixed roof usually gets all three in the right order.
The slow methods have a cost, which is patience. A treated roof does not look clean the next day, and the result builds up over weeks as rain washes the dead growth away. An owner who wants a clean roof for a sale or a photograph on a fixed date should say so before the work starts, because it affects the choice.
Our guide to water pressure on a roof gives the reasons a lower pressure is preferred, and the coating guide below explains what follows a wash.
Why a hard jet harms concrete
A hard jet is quick, and on a clean-looking roof it can seem to work. The trouble is that a strong jet takes more than growth. On many concrete tiles the colour sits in a surface layer, and a hard jet can strip it, leaving a bare face, and Marley says jet damage to the surface reduces a tile's expected life. A roof cleaned that way can look good for a season and then go dark again.
A jet also loosens moss so that it falls in clumps into the gutter. On a roof with cracked tiles it can finish them off.
If a quote promises a fast blast to leave the roof looking new, ask:
- What pressure is used, and how close is the lance to the tile?
- What happens to the surface coat, and has the roofer looked at it first?
- Where will the loosened moss and the run-off go?
- Who deals with cracked tiles the clean reveals?
You are entitled to a clear answer to each. A cleaner who knows concrete tiles will describe the method in plain words and will not promise a result the tile cannot give.
Walking on concrete tiles carries its own risk. A tile that has lost its face is slick when damp, and a cracked one gives way under a foot. Access is planned first, and we do not step on tiles already seen to be cracked.
Repairs and checks while the roof is clear
Cleaning shows the roof as it is, so it is also the time for a check. Once the growth is off, the cracks, slips and gaps are visible, and any repair can be done on the same visit while the access is in place.
The things to look for are the same on any tiled roof, with a few points particular to concrete:
- Cracked or broken tiles, which are replaced with tiles that match the profile and fixing of the originals.
- Slipped tiles, which point to nails that have rusted or battens that have lost their grip.
- Ridge and hip tiles, where mortar may have cracked or fallen away, and where a dry-fix system under BS 8612:2018 is the modern alternative.
- The verges, where the mortar is exposed to the wind.
- Gutters and downpipes, which take the moss and the sand that wash off.
Checkatrade, in June 2026, gave repair rates for concrete tiles of £90 to £120 per m², ex VAT, based on a maximum of 3m². That is for a small area, and it is not a price for a whole slope. For one to six tile replacements, the Which? figure of £75 to £400 ex VAT, from November 2025, is the better guide. Both are typical UK ranges, and prices sit higher in the South East.
If the repairs mount, a re-cover may be the better buy. Our page on roof coatings covers the other option for a worn, sound roof.
Cleaning, coating or re-covering: what to decide
After the survey you have three realistic routes, and which fits turns on the state of the tiles. A clean alone suits a sound roof gone dark. A clean followed by a coating suits a sound roof with a worn face, where the aim is to slow regrowth and even out the colour. A re-cover fits a roof whose tiles are failing, because new work on tired tiles is money spent twice.
Points that help the decision:
- How many tiles are cracked, slipped or flaking, and where.
- Whether the problem is on one slope or all of them.
- How the gutters and ridge look once the roof is clear.
- Whether you plan to stay in the house or sell it, and how long you want the result to last.
The price of a clean is set after a survey. Roof size, pitch, access, the amount of growth and any repairs found all move it. Where scaffold sits over the footway, Kent County Council grants the licence on the scaffolding firm's application, and that is added to the programme of the job. The fee is £52 per week for 2026 to 2027, with 5 working days of notice.
We look at the roof before anything is priced, send you photos of your own tiles and then give one written total price. If the honest advice is that the tiles are past a clean, that is what the survey will say.
