Roof Cleaning in Northampton

What Happens If You Leave Moss on Your Roof

Moss holds moisture against the tile surface. Over months and years, that moisture works its way into hairline cracks, and when winter arrives, it freezes and expands. Tiles crack. Mortar between ridge tiles crumbles. Water finds a way into the felt and timber below.

The weight adds up too. A thick layer of wet moss on a full roof can add hundreds of kilograms of load that the structure was never designed to carry. Gutters clog faster because every rainfall washes loose moss into the channels, which leads to the overflow and damp problems we see on blocked-gutter callouts.

The longer you leave it, the more expensive the eventual repair. A roof clean now is a fraction of what a re-tiling or structural repair costs later.

How We Clean Roofs

Every roof clean starts with a site survey. We visit the property, assess the tile type, check the ridge mortar, and look at access options. We also ask to inspect your loft space before any work begins. Checking the condition of the roofing felt from underneath tells us whether the roof is suitable for cleaning and flags any existing issues that need attention before we start.

This matters because different roof tiles need different treatment. Some concrete tiles have a factory-applied laminate coating that protects against water absorption. Others don't. Clay tiles behave differently to slate. Using the wrong cleaning method on the wrong tile type causes damage that wouldn't have happened if the roof had been left alone. We're Lantra certified for roof cleaning, which means we've been formally trained in the correct techniques for each tile type rather than guessing.

Once the survey is done, we remove the bulk of the moss, lichen, and algae from the tile surface by hand. This is careful work. We avoid dislodging tiles, we don't force debris into gaps, and we clear everything from the property when we're finished.

Then we apply a professional-grade biocide treatment across the entire roof. This is included in every quoted price. The biocide penetrates into the tile pores and kills the remaining spores and root systems that you can't see from the surface. Without this step, moss grows back within months. With it, your roof typically stays clear for three to five years. In many cases, roofs we cleaned over five years ago still look well maintained today.

Why We Don't Pressure Wash Roofs

Pressure washing strips the protective surface layer from tiles. On concrete tiles with a factory laminate coating, that coating is the tile's main defence against water absorption. Blast it off with a pressure washer and the tile becomes more porous, absorbs more moisture, and grows moss faster than it did before the clean. On tiles without a laminate, pressure washing roughens the surface and creates more texture for moss to grip onto.

High-pressure water also gets forced under tile overlaps and into the felt beneath. On older roofs, it cracks tiles that are already weakened by frost damage. You end up with a roof that looks clean for a few weeks, then deteriorates faster than if you'd left it alone.

Our biocide method works with the tile rather than against it. The treatment soaks in, does its job over the following weeks, and leaves the tile surface intact. That's why the results last years rather than weeks.

How Our Biocide Treatment Works

The biocide we use is a professional-grade DDAC (Didecyldimethylammonium chloride) formulation. It works by bonding to the porous surface of the tile and creating a chemical barrier. Every time it rains, the treatment activates and releases a controlled dose that kills new moss and algae spores before they can establish.

It takes between six and twelve months for the biocide to reach its full depth of penetration. During that time, you'll see the roof's appearance continue to improve as deeper growth dies off. The treatment typically remains effective for three to five years, sometimes longer on south-facing roofs with good sun exposure.

When the treatment does eventually diminish, a top-up application is usually enough. You won't necessarily need another full clean at that point, just a fresh coat of biocide on an already clean surface. That's a quicker job and a lower cost than the initial clean.

Roof Types We Clean

Concrete Tile Roofs

Concrete tiles are the most common roof type across Northamptonshire. The textured surface and joints between tiles trap moisture and encourage moss growth. Some concrete tiles have a factory-applied laminate or acrylic coating that protects against water absorption. We identify whether your tiles have this coating during the survey, because it changes how we approach the clean. Pressure washing would strip it off. Our biocide method preserves it.

Clay Tile Roofs

Clay tiles are softer than concrete and need gentler handling. We scrape carefully to avoid cracking, and we use lower concentrations where appropriate. Clay tiles respond well to biocide treatment because the porous surface absorbs and holds the product effectively.

Slate Roofs

Natural slate is durable but can be brittle, especially on older roofs where individual slates may have weakened over decades. We use minimal mechanical scraping on slate and rely more heavily on the chemical treatment to do the work. The biocide bonds well to slate's dense surface, and customers with slate roofs often see the longest-lasting results.

Roof Cleaning Prices

Every roof is different, and we price based on size, tile type, moss coverage, and access requirements. These are typical starting prices for residential properties in Northamptonshire:

All prices include the full site survey, loft inspection, manual moss removal, biocide treatment, gutter clearance, and debris removal. The price we quote is the price you pay. No extras, no surprises.

Want a price for your property? Call 0800 999 8594 or message us on WhatsApp for a quick response.

What's Included

• Full site survey including loft inspection to check felt condition
• Tile type assessment to determine the correct cleaning method
• Manual moss, lichen, and algae removal from all tiles
• Ridge tile and mortar inspection
• Professional biocide treatment included in every quote (lasts 3 to 5+ years)
• All debris cleared from the property
• Gutter clearance included (gutters fill with moss during a roof clean)
• Lantra certified team, trained in safe roof cleaning methods
• Full insurance cover (£10m employers' liability)

Bundle With a Full Exterior Clean

Most customers who book a roof clean also need the gutters cleared and the fascias and soffits cleaned. The whole roofline tends to deteriorate at the same rate, so it makes sense to sort everything in one visit. We can quote for a combined package that covers the roof, gutters, fascias, and windows together.

Roof Cleaning Across Northamptonshire

We're based in Northampton and clean roofs across the county. Our regular coverage includes Kettering, Wellingborough, Corby, and Daventry, plus the towns and villages in between. If you're within about 30 miles of Northampton town centre, we can get to you.

Frequently Asked Questions

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