How long does a roof clean take?

Four factors do most of the work in setting the schedule. Area comes first: a terraced house with one main slope is quicker than a detached house with two slopes, a rear extension and a garage. The second is thickness. A light film comes off quickly, while a dense mat in the laps has to be lifted in sections.

The third is the covering. Smooth modern tiles are quicker to work than old stone slates or hand-made clay, which need slower, more careful handling. The fourth is access. A roof reached from a drive with room for a ladder or tower is simple. One hemmed in by a steep lane, a neighbour's wall or a conservatory below takes longer to set up, and sometimes needs a scaffold.

Weather plays a part too, because roofs should not be worked on when they are wet and slippery or in strong wind. We plan around that rather than rushing, and it is one reason we do not quote a fixed time before a survey.

Hand scraping is slow because it is done slope by slope, working with the laps, and everything that comes off has to be collected. MyBuilder's 2026 figures for manual scraping come to about £5 to £10 per m², and the hours spent on the slope are the main reason it costs what it does.

Soft washing is faster to apply, since the biocide is sprayed over the roof at low pressure. It is not the end of the job, though. The treatment is left to work, and dead growth gradually washes off over the following weeks. MyBuilder gives soft washing at about £15 to £20 per m². Pressure washing is quicker still, at £10 to £15 per m², but the same guide notes that it may damage delicate tiles, which is why we compare the options in our guide to why pressure washing can damage your roof.

So a quick job is not always a better job. Speed is a trade-off against care.

As a rough guide, and without suggesting a fixed duration: a garage or porch roof with light growth is a short visit. A small terraced house or bungalow with moderate moss is a day-sized job. A semi or detached house with thick moss, several slopes or a stone covering is likely to take longer, possibly across more than one day, especially if scaffold access or gutter work is included.

Commercial and outbuilding roofs vary even more. A large flat roof may be quick to brush but slow to dry and inspect, and we cover those in cleaning a flat roof. Conservatory roofs are small but fiddly, as the glass or polycarbonate must not be scratched, and they are covered in conservatory roof cleaning.

These are shapes of job, not promises. Only a survey settles the real picture, and the quote we send afterwards says how many visits we expect and what each involves. Should the roof prove to want repairs too, those are agreed apart from the cleaning, so you can choose to do one without the other.

The time on the roof is only part of it. Before work begins, the area below is protected, ladders or towers are set up, and the roof is checked for loose or cracked tiles that need care. After the main clean there are gutters to clear, downpipes to flush and the ground to sweep, and we sweep up and take the debris with us.

If anything is found while the moss is off, such as slipped tiles or failed ridge pointing, it is recorded and discussed rather than patched in a hurry. Some of that can be dealt with during the same visit once you agree, and some may need a separate booking. Our guide to what happens on a Stroud roof clean, step by step sets out the order of work.

If treatment is applied, a further wait follows before the roof reaches its final appearance, so the day of the clean is not the day it looks its best.

If you need to be home, say so when you book, and tell us about any parking limits, narrow gates or steps up to the house, because a steep Stroud lane can add real time to unloading and setting up. If you work from home, tell us that as well, since a scraping and brushing job is not quiet. If cars, bins or washing lines are close to the house, they should be moved. Pets and children should be kept clear of ladders and the work area, and windows on the side being treated closed for the day. Tell us if neighbours share a wall or an access lane.

It also helps to think about timing. Growth is often easier to deal with before it thickens, and black marks on a roof, covered in black streaks on a roof, are a separate issue that may need different handling.

For the whole service, see roof cleaning and moss removal. We give a 10-year workmanship guarantee in writing on our work, and you can ring 01453 933613 to go over timings and access before you decide.