Roof cleaning cost in the UK typically runs £8.50–£14 per square metre, or £375–£1,125 for an average semi-detached home depending on the method used. Moss is usually the reason people start pricing this up in the first place — and moss on a roof isn’t just cosmetic: left long enough, it genuinely can cause leaks. This guide covers both sides: whether moss on your roof actually matters, and what dealing with it costs.
Yes — moss on a roof is more than a cosmetic issue, and left alone it can genuinely cause leaks. According to Roundhay Roofing’s guide on moss and roof leaks, moss blocks the natural flow of water down a slope, holds moisture against the tiles, and can force water to run sideways under the roof covering rather than down and off it.
Moss grows where a roof stays damp and shaded for long periods — north-facing slopes, roofs under overhanging trees, and older or more porous tiles are all more prone to it. Spores land, take hold in the tiny pits and joints of the tile surface, and spread fastest through autumn and winter when the roof rarely gets a chance to fully dry out between rain.
Yes, and this is the part that turns a cosmetic issue into a costly one. Moss holds water against the tile surface for much longer than bare tile would, and as it spreads it can lift tile edges slightly, creating a path for water to track sideways and under the roof covering rather than draining straight off it.
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Roof cleaning costs £8.50–£14 per square metre depending on the method, or £375–£1,125 for a typical semi-detached home. Per Checkatrade’s roof cleaning cost guide, pressure washing averages £8.50/m² and runs £375–£900 for a full semi-detached job, while hand-removal with a biocide treatment averages £11.50/m² and runs £600–£1,125 — more expensive upfront, but better at stopping moss coming straight back.
| Method | Cost per m² | Typical Semi-Detached Job |
|---|---|---|
| Pressure washing | £5 – £12 (avg £8.50) | £375 – £900 |
| Steam cleaning | £9 – £13 (avg £11) | – |
| Hand-removal + biocide | £8 – £15 (avg £11.50) | £600 – £1,125 |
| Soft washing | £12 – £16 (avg £14) | – |
Pressure washing alone clears moss quickly but doesn’t stop it coming back, since it doesn’t treat the spores left behind in the tile surface. Hand-scraping followed by a biocide treatment costs more upfront but, per Checkatrade’s guide above, does a better job of actually stopping moss returning — worth the extra cost if you don’t want to be paying for the same job again in two years.
Yes — if scaffolding or access equipment is already going up for a roof clean, it’s worth having the gutters cleared at the same time rather than paying for access twice. Moss scraped off a roof tends to wash straight into the gutters below, so a roof clean without a gutter clear can just move the blockage rather than solve it; our guide to gutter repair vs replacement covers what to check if your gutters are already showing signs of a problem.
A light dusting of moss on a well-maintained roof usually isn’t urgent, but once it’s thick enough to hold visible moisture or you can see it lifting tile edges, it’s worth dealing with before it causes a leak rather than after. If you’re not sure which category your roof is in, a proper look at it settles the question — our guide on roof inspection cost and whether it’s worth it covers what that involves.
A proper quote should say clearly which method is being used, whether it includes a biocide treatment to stop regrowth, and whether the price covers the whole roof or just the visible moss patches — a single vague figure usually means the scope isn’t fixed yet. JW Roofing Solutions carries out roof cleaning, moss removal and gutter clearing across SouthWest London, alongside our full range of roofing services. Every quote is written, detailed and free with no obligation.
Get a free, no-obligation roof cleaning quote from JW Roofing Solutions — we’ll take a look, tell you honestly whether the moss is a problem yet, and give you a clear written price either way.
Is moss on a roof bad?
Yes — beyond looking untidy, moss holds moisture against the tiles and can eventually cause leaks by blocking water flow and lifting tile edges.
How much does roof cleaning cost in the UK?
£8.50–£14 per square metre depending on method, or roughly £375–£1,125 for a typical semi-detached home.
Can moss on a roof cause leaks?
Yes. Moss holds water against the tile surface and can lift tile edges over time, creating a path for water to get under the roof covering rather than draining off it.
What causes moss to grow on a roof?
Shade, damp and poor drying time — north-facing slopes, roofs under trees, and older or more porous tiles are all more prone to moss growth.
Should gutters be cleaned at the same time as the roof?
Yes, if access equipment is already in place — moss scraped from the roof tends to wash into the gutters below, so cleaning both at once avoids paying for access twice.
If your roof has visible moss or you’re not sure whether it’s a problem yet, contact JW Roofing Solutions for a free, honest assessment and a written roof cleaning quote covering your SouthWest London property.
