Roof Cleaning and Coatings: Our Price Guide +Much More
Roof Cleaning Price Guide For 2021
Roof Coatings - Your Options
How to Stop Moss Growing Back
Get a Custom Quote Online
Roof cleaning is an effective method of removing roof moss, lichen, dirt and other contaminants from roof tiles.
The result is a roof that looks fresh and clean.
For roofs with very old and weathered tiles, there’s the option of roof coatings – these coloured paints drastically improve the kerb appeal of the home and can act as a protective layer on the roof.
On this page you’ll discover:
- A realistic price guide for roof cleaning and separately for roof coating.
- Products that stop moss from growing on roof tiles.
- What roof coatings do and can’t do (we dispel some myths and salesman’s claims)
- Where you can get a quote.
- Alternatives to roof cleaning.
- + many more answers to common questions in our FAQs section.
Note: The price guide on this page is for roof cleaning with a power/pressure washer. To see our guide to roof moss removal, i.e. done with hand tools such as brushes and scrapers, check our guide to roof moss removal.
To understand how much it really costs to clean a roof, experts and consumer protection groups advise that customers should get at least 3 quotes and compare them.
We took things a little further by asking 32 roof cleaning and coating specialists how much they thought it would cost to power wash a roof and coat it with coloured protective paint.
We requested two separate prices, one for roof cleaning and one for roof cleaning and coating.
Here’s a works schedule for a roof cleaning project, it’s based on the information provided to us:
- Raise platform access towers to the roof edge (this provides edge protection for workers on the roof as ladders cannot be used alone).
- Protect the garden and surrounding areas with covers and tarpaulins.
- Gain access to the roof via roof ladders.
- Check for broken roof tiles and replace as needed.
- Clean the roof tiles with a power washer.
- Clear out gutters and clean exterior of gutters.
- Clean the roofline fascias, soffits and bargeboards.
- Check rainwater pipes to ground level and unblock as required.
- Spray the roof tiles with a fungicide treatment to kill off any moss spores which will deter the moss from growing back.
- Allow the roof to fully dry and then apply two layers of coloured coating.
- Lower the access platforms and take away all waste.
Below you’ll find the two price guides:
1) Cost to Clean a Roof
This price guide is for roof cleaning only:
2) Cost to Clean and Coat a Roof
This price guide is for roof cleaning and then coating a roof with a coloured protective paint:
How to Stop Roof Moss and Lichens From Growing Back
The vast majority of roofs in the UK are covered in either clay or concrete tiles, and these have rough surfaces which are conducive to the growth of moss, algae and lichens.
In fact, the “dirt” you see on roof tiles is really nothing more than organic growth, and once this has been removed, its return can be prevented by the application of a fungicide.
Whether you’ve had the moss from your roof removed manually with hand tools or with a power washer, a fungicide should be applied to stop the moss from growing back.
The most popular chemical for external hard surfaces is Benzalkonium Chloride which acts as a surface biocide.
If you’ve chosen to have your tiles coated, then the surface should now be smoother and moss, algae and lichens will find it more difficult to grow.
What Happens if a Fungicide Isn’t Applied?
If any moss spores are left on the roof, they will start to grow as soon as they get wet. At first, small sprouts of moss may form, often appearing in a matter of weeks, especially if it’s winter.
More widespread moss growth will form within a year, first on shaded parts of the roof before migrating to all other areas.
The photo below shows moss growing between the tile overlaps where moisture lingers, and organic material such as leaves, twigs and dust etc. collects.
This type of moss growth will appear regardless of whether the tiles have been coated with protective paint or not. Its growth can be contained with periodical fungicide treatments.
How to Permanently Stop Roof Moss and Lichens Growing Back
While no one product or technique will stop moss from forming on roof tiles, this is the best approach:
- Have the roof demossed or cleaned by a professional.
- Get them to apply a strong fungicide.
- For roofs suffering from prolific moss growth, consider a roof coating that will smooth the tile surface, making it difficult for moss and lichen to grow.
- Apply a fungicide to every few years to stop moss growing on the surface of the tiles in the overlaps.
Once thoroughly cleaned, a fungicide can be applied every few years to stop moss and lichen regrowth. This photo shows a long lance being used to apply the chemical, negating the need for costly access equipment such as scaffold.
Extra Roof Cleaning Costs to Consider:
The prices we’ve published on this page are for a straight-forward roof cleaning and coating project to a typical 3-bed home with an up-and-over roof.
Unfortunately, not every project is as easy as this, so use our guide as a starting point and consider these points:
Access Equipment – We’ve included the cost of access equipment in the form of tower platforms for edge protection and ridge ladders to access the roof. However, some roofs may require a full scaffold system which would cost extra. If your roof is three or more storeys high, has a large conservatory underneath it or is otherwise difficult to access, the moss removal project will cost more.
More Substantial Repairs – Before cleaning the roof, every contractor should first check for and then replace any broken roof tiles. More substantial repairs, such as replacing a roof valley, will need to be priced separately.
Roof Size – Our prices are for an “up and over” roof, that you would typically find above a three-bed home. Larger roofs, split level roofs or those that are very steep will take longer to clear of moss and cost more.
Tile Type – Moss can be removed from any roofing tile, and most roofs in the UK are covered with concrete tiles, these are tough and difficult damage. Clay tiles are less popular but are more fragile, and specialist access equipment might be needed to access the roof without damaging them.
Roof Coatings: Key Benefits and Myths Dispelled
The main benefit of roof tile coatings are aesthetic; there is no doubt that a recently painted roof will look fresher and cleaner than an old weathered one.
Tiles with a rough surface will see less moss growth once coated with smooth paint as this makes it difficult for moss and lichen to take hold.
There are, however, several myths that are usually perpetuated by eager sales staff and occasionally by outright fraudsters:
- Coatings can increase house value – There is no evidence that a freshly painted roof will increase the value of a home. In fact, many homeowners like the look of a weathered roof. You won’t find many homes in Country Life magazine that have had their roofs painted.
- They increase the life of the roof – Most tiled roofs will last for many decades, and some constructed over a hundred years ago are still holding up well. Roof failure is usually due to the timbers rotting or disintegrating, which causes tiles to slip or come loose, rainwater then enters the roof and causes more damage. It’s extremely rare for a roof to need replacing due to failure of the roof tiles themselves. Several firms have been prosecuted for making dubious claims about the benefits of roof coatings.
- Roof coatings can lower your heating bills – This claim was perpetrated by a few dozen firms that have now mostly disappeared. Several high-profile court cases brought by the UK’s Trading Standards have all but driven these firms out of business. The vast majority of tiled roofs in the UK are constructed over ventilated lofts. There is no thermal benefit to be had by painting tiles over a vented, cold loft. Insulation in most homes should be placed between in the wall cavity or above the ceiling, not on top of the roof tiles.
- Government grants and discounts – The government has never offered grants or subsidies for roof cleaning or coating despite fraudulent claims by some firms.
Get a Roof Cleaning Price Here
We hope you found our insights into roof cleaning and coating helpful.
As every project is different, the next step is to get a no-obligation custom quote for your roof:
- Submit details of your roof cleaning or coating project.
- Arrange a convenient time for a roof inspection.
- Get your custom quote.
- Compare prices.
Get a Custom Price
Roof Cleaning FAQs
When Were These Roof Cleaning Prices Published? Do They Include VAT?
We asked 32 businesses of various sizes to provide us with prices for roof cleaning and coating in 2021. Some were VAT registered and included this tax, while some smaller firms that were trading below the VAT threshold did not charge this tax.
Why Can't The Fungicide Be Used to Remove the Moss?
The fungicide we recommend can kill moss, lichens and other organic growth but it won’t physically remove it from the roof. It could take months, possibly years, for the dead matter to decay. Rainwater would almost certainly wash it into the guttering, rainwater pipes and possibly the drainage soakaways where it would cause blockages.
The fungicide should be used as a surface biocide to clear the roof of spores once the bulk of the moss and other organic material has been removed and disposed of.
Why Can't Roof Cleaning Be Done From Ladders?
The Health and Safety Executive’s rules for working at height are crystal clear; any worker who spends more than a few minutes on a roof must ensure there is adequate edge protection in place to prevent falls.
In most cases, this will mean scaffold or a similar edge protection system must be in place at the edges of the roof to stop workers from falling.
HSE also state that group protection must take precedent over individual protection so scaffold or access towers should be used instead of or in combination with harnesses and ropes.
I've Been Told That a Roof Coating or Sealant Will Prevent Future Leaks, Is This True?
The coating or sealant that is sprayed onto the roof tiles is as thin as a layer of paint and will not prevent leaks.
Can a Flat Roof Be Power Cleaned?
Extra care will be needed when working on a flat roof as they’re more fragile than concrete tiles. Moss shouldn’t be scraped or power washed off a flat roof but if the roof is in good condition, one may be able to brush the moss off.
I've Been Given a Quote That is Considerably Higher/Lower Than The Figures on This Page. What Gives?
Our prices are for a roof clean to a two-sided roof above a three-bed home, they are a rounded average of prices given to us by 32 roofing and roof cleaning firms.
If your price is significantly below this average, you may want to ask the roofer if they will be erecting edge protection. It’s not uncommon for roofers to complete this type of work from ladders even though they would be breaking the law. Some even walk on the roof with no protection whatsoever.
If the prices you’ve been given are much higher than our averaged price, it could be that you’ve sourced prices from a firm that has more overheads and needs to charge more. In general, the bigger the firm, the more they need to charge to make a profit.
We recommend sourcing at least three quotes from reputable roofers and comparing their work schedule and price to the information on this page.
Where Can I Find a Good Roofer?
The National Federation of Roofing Contractors and the Confederation of Roofing Contractors are well-known organisations that maintain databases of approved roofing contractors in the UK. The Competent Roofer scheme promotes roofers that agree to adhere to a high set of standards.
We’ve also partnered with Rated People – one of the best places online for finding vetted, reviewed and rated tradespeople.
How Long Does it Take to Clean and Coat a Roof?
Roof cleaning and coating is a project usually completed over at least two days.
Day 1 is when the access equipment is erected, the roof inspected, repaired and then cleaned. The fungicide is then applied.
The roof is then allowed to dry. In summer this may only take a few hours, but in winter it could take several days.
Day 2 is when the coatings are applied. In summer it may be possible for two coatings to be applied in one day while in winter longer drying times may mean the second coat has to be applied on the third day.
For larger or more complex projects, the work will take longer.
Does Moss Damage Roof Tiles?
The vast majority of roofs in the UK are covered with concrete tiles, and for the most part, these are strong enough to prevent any damage from moss growth.
In extreme circumstances, for example, when the roof is carpeted in moss, it may eat away at the surface, which essentially accelerates the weathering process.
On more fragile clay tiles, the extra moisture held by the moss can lead to an increased risk of damage in winter due to the freeze/thaw process.
While wet moss is heavy, the weight never threatens the structural integrity of the roof as it’s spread thinly. Roofs in the UK are designed to withstand wind pressures and the weight of several feet of snow.
What is the Best Way to Remove Roof Moss?
If your goal is to remove the roof moss and stop it from coming back, then either manual roof moss removal or power washing techniques will suffice.
If you need the roof to be cleaned rather than just demossed, perhaps because you want to apply a roof sealant or coating, then it should be power washed.
What Are The White and Yellow Marks on Roof Tiles?
White and yellow marks on roof tiles are lichen, a slow-growing thin organism that’s very tough to remove.
The best way to remove it is by power washing or by treatment with a fungicide.
The fungicide requires time to work but 4-6 weeks after the application, most of the lichen should’ve disappeared.
We do not recommend trying to remove lichen with scrapers or wire brushes as they will scratch and scuff the tiles.
Discover More Price Guides:
By Quotation Check
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Discover all of our roofing and guttering cost guides here; from new flat roofs and simple repairs to gutter cleaning and Upvc roofline installations + much more.
Broken Roof Tiles
Discover how much roofers are charging to erect access equipment, go up on a roof and replace broken roof tiles. Also, get your own custom quote.
If your roof is covered in moss, you don’t necessarily need to have it power washed. Roof moss can be scraped and brushed off; the tiles can then be treated with a fungicide to prevent regrowth.
Their prices for roofline installations were correct; we were given quotes from several firms, all were similar to [Quotaton Check’s]
Excellent advise regarding tile sealants, I nearly paid £3000 for what I now believe to be a worthless product. Thank you for your help.
Why only rely on three or four quotes for comparison? This website called Quotation Check gathered prices from hundreds of firms for various home improvement tasks and published their findings online.
I never realised so many companies have been taken to court for selling this type of service. Your site is a gold mine of information.
Go see the prices on the Quotation Checker website; they’re suggesting a price for a new roof that’s much lower than that.