The Cost of Having your Roof Cleaned and Treated (Updated Feb 2020)

All you need to know about the cost of having your roof cleaned and treated.

Roof Treatment

How Much Does It Cost to Have Your Roof Cleaned and Treated?

The average cost of a full roof cleaning and treatment is between £600 to £1,500, but this can vary depending on several factors. For example, the size of the roof and how easily accessible the roof is will be taken into consideration by the roof cleaner, giving you a quote. You can also expect the costs to be lower if you are getting both a clean and a treatment done.

There is a range of different roof cleans and treatments available:

  • A roof moss treatment has an average cost that's between £5 per m2 - £12 per m2.
  • The average cost of a roof pressure washing is £8 per m2 - £15 per m2.

Roof Cleaning and Treatment Prices

UK Prices Outside of London

Size of House Type of Treatment Average Cost
Small, detached Roof moss treatment £500
Small, detached Pressure washing £600
Semi-detached Roof moss treatment £650
Semi-detached Roof moss treatment £750
Large, detached Roof moss treatment £900
Large, detached Pressure washing £1,500


London/ South England

Size of House Type of Treatment Average Cost
Small, detached Roof moss treatment £650
Small, detached Pressure washing £750
Semi-detached Roof moss treatment £850
Semi-detached Roof moss treatment £950
Large, detached Roof moss treatment £1,000
Large, detached Pressure washing £1,500+


Additional Costs

If you are considering having roof tile treatment, then there are some other related jobs you may consider doing at the same time. There are also some issues that may prevent a roof cleaning, such as broken or damaged tiles.

In addition, you should also consider any other jobs that require scaffold at roof level, as you will already be paying for this so may as well make full use of it and take care of other minor roof repairs at the same time! If they are not included in the quote for roof cleaning, you may consider asking for a quote for additional work such as:

  • Gutter cleaning
  • Gutter repair and replacement
  • Exterior painting
  • Eaves felt replacement
  • House exterior clean
  • Fascia & Soffit work
  • uPVC cladding installation

Below are some common average costs for additional work that you may consider.

Type of Work Average Cost
Tile repairs – less than 5, without scaffolding £75
Tile repairs – more than 15, without scaffolding £125
Tile repairs – less than 5, with scaffolding £250
Tile repairs – more than 15, with scaffolding £325
Gutter cleaning – terrace property £40
Gutter cleaning – semi-detached £95
Gutter cleaning - large property £120
External house painting - smooth - semi-detached £750
External house painting - Pebbledash - semi-detached £1,000


Cost Breakdown Calculator

Individual costs for hiring a roofing specialist to clean and treat a gable roof on a semi-detached house - Total Cost: £1000

10%

Materials
£100

60%

Tradesmen
£600

30%

Scaffolding
£300

Labour Cost and Time Frames

A roofer will often charge around £150-£200 per day to coat a roof. Tradesmen will likely work in pairs in order to complete the job for safety precautions as well as to get the job done faster, as such you should expect to pay around £250 per day in labour costs.

Roof cleaning time frames will vary according to the size of the roof and the condition of the roof, as well as which kind of treatment the roof needs.

Size of House Type of Treatment Average Time Frame
Small, detached Roof moss treatment 1 day
Small, detached Pressure washing 1 day
Semi-detached Roof moss treatment 2 days
Semi-detached Roof moss treatment 2 days
Large, detached Roof moss treatment 2 days
Large, detached Pressure washing 2 days


  • Average size of a roof on a small detached house: 55 square metres.
  • Average size of a roof on a semi-detached house: 75 square metres.
  • Average size of a roof on a large, detached house: 100 square metres.

For a two-day job, day one usually starts with any required remedial work as well as cleaning and then applying the fungicide. Day two would then be coating the tiles with the coloured paint/sealant. Once the first coat is dry, a second coat can be applied.

What Does Having a Roof Cleaned and Treated Entail?

For homeowners, the thought of needing work done to your roof is usually a daunting prospect. We associate roof repairs and treatments with high costs – and, unfortunately, this can sometimes be the case. That’s why it’s usually better to be on the offensive, rather than the defensive when it comes to your home’s roof. Making sure your roof is regularly cleaned and treated is a good place to start. It can also vastly improve the appearance of your home, giving it that ‘just built’ look again!

When hiring a professional roof coating and/or pressure washing company, the first step will be an initial site survey to check access to the roof and inspect the area affected by moss build-up. The general condition of the roof will be checked too for safety reasons, including checking for broken tiles, ease of access with scaffolding and any holes. Then the job will entail the setting up of the safety equipment such as scaffold towers or harnesses and roof ladders.

Covers and tarpaulins will normally be placed over patios and flowerbeds to protect them, and any broken or damaged roof tiles will be replaced. Before he roof is washed, the gutters may be removed from drainage pipes to prevent debris from the roof blocking the drains.

Any further steps may differ depending on what type of treatment you're having done.

What Does a Roof Moss Treatment Entail?

A roof moss treatment consists of:

  • Moss on the roof will be manually removed by scraping.
  • Any debris on the roof and in the gutters will be removed.
  • An anti-fungal moss treatment being applied to the roof.
moss roof treatment

The Cost of a Roof Moss Treatment

The average roof moss treatment costs from £500 for a small semi-detached up to £1,400 for a large detached house.

What Does a Pressure Washing Treatment Entail?

A pressure washing treatment consists of:

  • Debris on the roof and in the gutters will be removed.
  • The company will select the correct pressure control for the type of roof being cleaned.
  • The roof will be fully cleaned with a pressure washer if suitable.
  • An anti-fungal moss treatment will be applied.

The Cost of a Pressure Washing Treatment

The average cost for pressuring washing is between £400-£900; again, this will depend on the size and type of roof your property has. If your roof is in a bad state, this may increase the costs too.

Roof Coating

Many roof cleanings and pressure washing treatments will also include a treatment of roof coating.

The average cost of a roof coating for a semi-detached house is between £1,500 to £2,000.

This depends on the size of the house as well as the area. For a larger house in London, you can expect to pay a higher average of £2,000. In the North of England, you may pay around £1,500.

Roof coatings are coloured paint which helps to seal the tiles, and they are usually applied to improve the aesthetics of the roof. However, much like the painting of exterior brickwork, once you have done the job once, you need to continue repainting it regularly, though most paints/coatings should last 6 to 8 years.

Though the job is mainly done for visual appeal, the roof will be thoroughly cleaned and have a fungicide applied as part of the job, so it will help if you experience a lot of moss growth and may even help to reduce leaking gutters with a better flow off the roof and no moss leading to blockages and overflows.

roof coating

These types of paints/coatings shouldn't be applied to roof tiles in winter or during damp conditions as they may not cure properly. It is best to wait for the warmer, dryer weather in the summer months. Remember, a roof coating can make old roof tiles look like new, but it's no substitute for a new roof if the tiles are well past their prime. In fact, if the roof is in poor condition, reputable companies will refuse to apply a coating and risk their reputation.

What Are the Chemicals in Roof Coating?

The main chemicals in roof coating that benefits the tiles are:

  • Acrylic Polymer Resins
  • These resins provide strength, durability and toughness to your tiles. The resins provide the coating with flexibility and also act as durable binders that hold the coating together, providing adhesion and water-resistance.

  • Fire Retardants
  • These chemicals provide essential coverage to your roof in the event of a fire. They suppress smoke generation and stop flames from spreading further.

  • Titanium Dioxide
  • This is a pigment that adds durability and reflectivity. It makes the coating white, blocking UV rays from reaching the materials below.

  • Zinc Oxide
  • This chemical is really important in resisting the growth of algae and mildew. It’s tough and water-resistant. Aslo, it doesn’t deteriorate after being exposed to UV rays.

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What are the Benefits of Roof Coating?


Helps to seal tiles

A roof coating will help to seal the tiles, preventing rainwater from getting in and causing damage to your property. It also slows down the process of moss growth and protects from UV damage.

Improves aesthetics of the roof

There are a variety of colours, such as red, grey, black and terracotta, to choose from. Instead of appearing weathered and outdated, your roof will look brand new once more!

Roof is cleaned during process

Getting your roof cleaned is important to elongate its lifespan. It helps prevent damage that moss and algae can cause, such as broken tiles that can lead to leaks both inside and outside your home. If left uncleaned, a roof can become damaged to the point of causing internal property damage, such as mould and damp.

cleaned and treated roof

Most roof coating is done for cosmetic reasons, with some minor benefits due to a thorough roof cleaning and moss treatments being part of the job. However, there are some companies which promise greater insulation properties and lower heating bills amongst other things - this is unlikely to be true so caveat emptor! Despite the contrary claims made by aggressive salesman, there are no government grants for roof coatings at this time.

If you want to reduce heat loss through your roof, then additional loft insulation is the best option, and this does often attract grants and incentives and can even be done for free depending on your circumstances. Before having your roof painted/coated, remember that once painted you will need to have it repainted at least every 10 years, whereas roofs can often last up to 70 years without major remedial work if you don’t mind that weathered look!

Cost Affecting Factors of a Roof Clean and Treatment

How much a roof cleaning and roof moss removal costs depends on several aspects:

  • The type of treatment
  • If you are simply getting a moss removal treatment, then the cost will be less than if you also need a pressure washing or if you opt for a roof coating.

  • The size of the house
  • The bigger the house, the bigger the cost! Also remember to consider additional buildings and add-ons, such as a garage, into the overall cost.

  • The type of roof
  • Certain types of roof will be easier to work on, while others might require less treatment.

  • The area of the UK you are living in
  • Any roof treatment is likely to cost substantially more in areas of the south of England, such as London.

  • The amount of moss
  • If a roof has a lot of moss or requires a lot more cleaning, then this will cost more than a roof with only mild moss problems.

  • Access to the roof
  • When considering their quote, roof cleaners will strongly consider how easy it is to access the roof. This is because a difficult-to-access roof will require more work on their behalf, with scaffolding etc., as well as an added danger involved for areas that are awkward to reach. You can expect to pay around £400-£600 more for a difficult to erect job. In London, this could cost between £650 - £1,000 plus.

Can My Roof be Cleaned and Treated?

There are some roof issues that may prevent your home’s roof from being cleaned. These include:

  • Broken or damaged tiles
  • If tiles are damaged or broken, then this issue will need to be addressed before any cleaning and treatment can be carried out. This is because damage to tiles can cause further complications to a roof, such as leaks and mould. If there are already gaps or holes in the roof, then it's possible that any roof cleaning and treatment chemicals could go inside, into the attic and cause damage. The average cost of new tiles is £70-£100 per roof tile.

  • No safe access to your roof
  • Not all roofs are accessible. For terrace houses and some semi-detached, roof access can be tricky. Extra scaffolding will need to be used, for example, building a ‘bridge’ over a house or a conservatory. There will almost certainly be extra costs associated with this. You can expect to pay around £400-£600 more for a complex job. In London, this could cost between £650 - £1,000 plus.

  • Tiles are too old and need to be fully replaced
  • If your roof is too old or too damaged, you may be facing a full roof replacement. This is not just because it would be too dangerous for anyone to work on the roof, but it is also because your home is at risk of severe damage from leaks and black mould. The average price of a full roof replacement is between £3,000-£5,000.

  • Roof is too badly damaged – holes etc.
  • If a roof is too damaged and unrepairable, you might have to consider a full roof replacement as many roof cleaners won't attempt to go near it. The average price of a full roof replacement is between £3,000 - £5,000.

  • Damaged gutters
  • If the gutters on your home need replaced because they are too damaged, then this job will need to be completed first. The average cost of installing new guttering is between £450-£700.

    Although you may need to be aware of the problems yourself, the roof cleaner will be able to tell you about these problems when they assess the roof as part of the quotation process.

roof needs cleaning

Does My Roof Need a Clean and Treatment?

It is often obvious if your roof needs a clean due to visual signs: a visual inspection will show a large growth of moss on the roof. There are some other signs you should look out for:

  • Roof shingles have lifted or moved due to moss build-up.
  • There are black or dark green streaks on the tiles.
  • Gutters are full of moss and/or leaking.
  • Roof has not been cleaned in 3 to 5 years.

How often you need to clean and treat a roof also depends on the type of roof:

Type of tiles Frequency to clean and treat
Concrete tiles 2 – 3 years
Asphalt composite shingles 7 years
State tiles 10 years
Cement tiles 2- 3 years


Types of Roof Cleans

The type of roof has an effect on the method used to clean. If the wrong method is adopted for the wrong roof type you risk causing permanent damage and extra costs.

Material of roof Type of clean required
Slate roof Moss removal/gentle pressure wash
Thatched roof Brushing/raking
Clay tiles Moss removal/ pressure wash
Concrete tiles Gentle pressure wash


DIY Roof Cleaning

Roof cleaning is an extremely dangerous job and is best left to the professionals. That’s due to both the height of the work and risk of fall, as well as the risk of causing more damage to the roof – which could result in even more costs to repair.

If you do wish to attempt cleaning a roof yourself, it’s important you know exactly what type of roof tiles you have and what condition they are in. Remember, you could cause more damage than good!

In particular, using a pressure washer yourself is generally considered a bad idea. This is because some tiles can be extremely precarious i.e. very easily damaged.

diy roof cleaning

It’s recommended that instead of attempting to ‘wash off’ any moss if you must do something, then you can try to very gently scrape off the moss by hand.

Do keep in mind that any time you’re climbing up a ladder, there is a risk. Make sure not to attempt any roof work by yourself – have someone around who can help if anything were to go wrong.

DIY Roof Treatment

As explained above, any work on your roof should be left to the professionals. If you do wish to remove roof moss manually, take extreme caution as it's dangerous work. Not only is there a risk of falling, but many roof treatments can cause skin irritation, eye damage and other risks. Always read the label carefully and take all the recommended precautions.

There are several products available for DIY roof treatment. These include:

  • Roof moss killer: a special cleaning agent that can be bought at most DIY stores. It is sprayed onto the roof and absorbed over several hours, depending on the particular brand. It may need several treatments if the moss is particularly heavy. You may need to wear a special suit and be extra careful to protect your eyes. The average price of a roof moss killer is £18-£30

  • Moss resistance treatment: This product is designed to slow down the growth of moss on a roof so can be used before a build-up of moss appears or after a treatment such as a roof moss killer. The average cost is around £15- £20.

Roof Treatment and Cleaning Chemicals

There are two basic types of products available for moss killing, both with their own advantages and disadvantages:

Dry powder moss killers

  • ✔ Works in a week
  • ✖ Hard to dispense
  • ✖ Can wash off in the wind

Liquid moss killers

  • ✔ Can be applied from the ground due to coming in a spray form
  • ✔ Can give more even coverage than a dry powder
  • ✖ Can be hard to keep track of where spray has been applied
  • ✖ Usually more expensive than a dry powder spray

Here’s the costs of some commonly found products available for cleaning and treatment.

Product Drying time Average cost
Roof cleaner spray 4 hours £18
Algaecide and Fungicide Treatment 2-4 hours £18
Moss, mould and algae cleaner 6 hours £29.95


Will Moss Damage My Roof?

There are several reasons that moss on a roof can cause problems that can become quite costly, including:

  • Causing frequently blocked drains. Blocked drains can cause leaks, overflows as well as a terrible smell!
  • Affecting the long-term condition of roof tiles.
  • Roof tiles becoming loose. Moss can cause tiles to move upwards, eventually breaking.
  • If left untreated, moss damage can eventually be the cause of leaks inside the home. This is due to broken tiles allowing water inside the house.
  • Looking and being in better condition should you wish to sell your home.
  • Preventing internal damage such as black mould/ damp.
  • Becoming unsightly and effecting property price.
moss damaged roof

The type of roof will be a factor, with several types of roof being less likely to have issues due to moss. The most common roof-types and parts of a roof that require moss treatment are clay tiles, cement and the brickwork on the chimney. It's essential to catch any sign of damage early. The average cost of replacing tiles is £70-£100 per tile whereas if the damage means you need a new roof you can expect to pay £3,500-£7,000.

Dealing with Algae and Moss

Moss is a type of plant that just loves damp, shady and cool conditions – so you can thank the British weather for the moss on your roof! North-facing roofs and roofs in the shade (for example, from trees) are also more likely to suffer from moss. Essentially, roofs with the least sun exposure and that stay wetter longer are most at risk from moss growth.

Unfortunately, there is no guaranteed way to prevent the growth and spreading of moss, but regular cleaning, treatments and maintenance will slow it down.

Another way to curb the spread of moss is to install copper ridges and copper wire. Copper is antimicrobial, meaning it prevents or stops the growth of microorganisms, such as moss and algae.

Copper ridges are fitted to the ridgeline of the roof. The copper causes a chemical reaction during rainfall leading to the water flowing downwards and preventing any further moss growth. Copper wire is installed along the ridgeline of the roof, underneath the slates.

Many new roofs are built with copper wire and ridges incorporated, but it is possible to install these retrospectively.

The average cost of installing copper ridges is £10 - £15 per metre.

copper roof ridges

Copper wire costs an average of £0.50 - £1.00 per metre, without installation.

It is worth noting that installing copper ridges or copper wire will not remove current moss and that all moss must be removed before any installation occurs.

Benefits of Having a Roof Cleaned and Treated

There are many benefits to choosing to get your home’s roof cleaned and treated. As well as improving the look of your home, the other benefits are:

  • Preventing damage to roof tiles, like tiles breaking due to being forced upwards.
  • Loose tiles can cause long-term damage, such as leaks inside the home.
  • Preventing clogged gutters.
  • Looking and being in better condition should you wish to sell your home.
  • Preventing internal damage such as black mould/damp.
  • A longer life expectancy for your roof.

FAQ's

Yes! In fact, DIY pressure washing is often not recommended. This is because you may use the wrong pressure of water/spray and cause damage to the tiles. This is why pressure washing is best left to the experts.
If you don’t want a roof cleaner to pressure wash the roof, you can choose just to have a roof moss treatment. This involves manually removing any moss by scraping. For some types of roof tiles, this is the safest method, for example, a thatched roof or shingles.
Yes, for most types of roofs, cleaning and treatment are required in order to avoid damage. Replacing a roof is a very costly business and, like all homeowners, something you should be trying to prevent!
Without cleaning a roof, it becomes suspectable to moss infestation which can lead to broken tiles, clogged gutters, internal back mould and a whole host of other issues. Cleaning a home’s roof will help your roof last for as long as possible.
Unfortunately, it can. This is why it’s best to call in the professionals! Certain types of tile and already-damaged roofs can be vulnerable and, if mistreated, can become further damaged. A professional will be able to fully assess the state of your roof and select the correct treatment moving forward.
This depends on the roof. For a roof with concrete or cement tiles, every 2 to 3 years is recommended. For a roof made of asphalt composite shingles, every 7 years should be fine, and for slate tiles, you can probably clean once every 10 years.
Some modern coatings come with a 10-year guarantee, but this may be slightly optimistic based on the experiences of other homeowners! Expect 6 to 8 years being more realistic. Remember also that guarantees are only valid if the company is still in business (unless insurance backed), so a guarantee from a fly by night cowboy company is completely worthless! To avoid future problems, stick to reputable companies with insurance backed guarantees that have a solid track record and history.
No, but it should reduce moss growth in the short term thanks to the fungicide treatment, which is part of the process. If your roof suffers from heavy moss growth, you will likely still need regular treatments.

How to Find and Hire a Roof Cleaner

If you want to find and hire a roof cleaner, there are a few things you should take into consideration before making any decisions. Enquire whether they have had any training or have any qualifications regarding roofing or roof cleaning, this will help you know that they’re a competent trader. Experience is also a crucial factor and asking for proof of previous jobs and customers is a must. You can then see what they’re capable of and ask previous customers if the trader carried out the job professionally. It’s worthwhile checking if they have liability insurance, it protects you and your property if anything were to go wrong.

If you want to find and hire a roof cleaner or treatment specialist located near you and receive free quotes, please click here.

Sources

https://www.brightroof.co.uk/roof-cleaning-cost.html
http://www.gotmoss.com/MossRoofing/faqs/index.asp
https://www.roofingsuperstore.co.uk/browse/pitched-roofing/dry-ridge-hips.html
http://www.copperstopsroofmoss.com/
http://www.copperridges.com/

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