Is pressure washing bad for my roof?

Yes, in most cases. High-pressure water can strip the protective granular surface off concrete tiles, making them porous and prone to frost damage. It also voids the warranty of major UK manufacturers like Marley and Redland. Manual scraping or low-pressure steam cleaning are the industry-approved methods.

How long does a biocide treatment last?

A professional-grade biocide (like AlgoClear or Benz Bio Cleanze) typically prevents moss and lichen regrowth for **2–4 years**. The chemical stays within the tile pores and continues to work every time it rains.

Why are 'Roof Coatings' discouraged?

The NFRC (National Federation of Roofing Contractors) warns that coatings can block the natural ventilation of the roof. By 'bridging' the gaps between tiles, they trap moisture in the loft space, which can lead to the rapid rotting of your structural timber rafters.

Restore Your Curb Appeal

Roof Cleaning Costs 2026

Moss isn't just an eyesore—it acts like a sponge, holding moisture against your tiles and causing them to crack during winter frosts. In 2026, professional roof restoration is a vital maintenance step to avoid a premature roof replacement.

Manual Scrape

The safest method. Moss is removed by hand using specialized scrapers. Ideal for delicate or older tiles.

£11.50 per m²

Steam Cleaning

Low-pressure, high-heat steam kills moss spores instantly. Provides a deep clean without the force of a pressure washer.

£11 – £14 per m²

Pressure Wash

Fastest but riskiest. Often voids tile warranties. Only recommended for specific non-porous surfaces.

£8.50 per m²

The Coating "Scam"

Many companies offer "Thermal Roof Coatings" or "Sealants" for £2,000+. The NFRC warns that these can:

Block essential roof ventilation gaps

Cause structural timber rot (condensation trap)

Make future tile repairs impossible

Fail to provide any measurable thermal insulation

Expert Advice

"Clean, Don't Coat"

A clean roof with a biocide treatment is all you need. Painting or sealing is rarely beneficial and often destructive.

Project Estimates (2026)

3-Bed Semi (Scrape + Biocide)£600 – £750

Scaffold Tower Access£300 – £600

Biocide Re-application (Every 3yrs)£150 – £250

Professional Process

A proper 2026 roof clean involves more than just a brush. It's a multi-stage preservation process.

Stage 1: Gutter ProtectionDownpipe bungs fitted

Stage 2: Manual Removal95% of moss cleared

Stage 3: Biocide WashResidual killing layer

Warranty Safe

Manual scraping and steam cleaning preserve your tile's original integrity and warranty.

Better Airflow

Removing moss blocks from tile laps improves natural ventilation in your loft space.

Property Value

A clean roof significantly boosts the 'kerb appeal' and market value of your home.

Roof Cleaning FAQ

Calculate Restoration Costs

Use our 2026 calculator to see if a professional clean is a more viable option than a full roof replacement.

Use the Calculator