Should I Clean My Roof

Should I Clean my Roof?

When we think about keeping our houses clean, our minds may go to hoovering the carpets, dusting the mantle, or polishing mirrors but the most important feature of the house is often missed out entirely. The roof. There is a tendency to neglect the very thing that keeps us warm and safe, leaving it to grow a vast assortment of algae and moss.

When a roof is left unclean for a prolonged time, many problems can arise, requiring costly remedies. Moss, lichen and mould can be catastrophic for a roof and can attract many pests. There are listless benefits to cleaning your roof, and the process of cleaning it is not as hard as you may think! We will explain why cleaning your roof is such an important task and give you our top tips on how you can do this.


Problems That Can Occur From an Unkept Roof

Multiple problems can occur when a roof is left unkept. Of course, the roof of a house is arguably the most important aspect. It keeps you and your family safe, warm and protected. Roofs endure all kinds of adverse weather conditions such as rain, wind, snow, hail and numerous years of strain, meaning that its strength is vitally important. With your roof playing such an important role, it is crucial to ensure that it is taken care of on and cleaned effectively.

Moss, Mould and Lichens

The lifespan of a roof can be shortened by organisms such as moss and lichen as they can cause damage to the area of tiles and shingles that they grow on. This is because they can hold large amounts of moisture which disturbs the integrity of the area, leading to cracks and additional moisture on the roof. This demonstrates why regular roof maintenance is so important in ensuring that your roof continues to function as it should and will continue to keep you safe.

One of the biggest problems that a roof will face is the impact that moss and mould can have on your roof. When a roof is left unattended, it allows moss and mould to grow which, over time, can grow under the roof’s shingles. This can be deadly for a roof, as it can compromise the structure’s integrity, which can lead to internal water damage inside the house. A highly expensive and unwanted outcome!

The moss and mould can also cause health problems which are explained later on (see ‘health benefits’). Lichens are organisms that are made from algae and fungus and can be found on trees, leaves, rocks and most importantly, roofs. They grow in sunlight and only require small amounts of moisture to survive. Lichen can be flaky and easily removed, however, it grows rapidly and in large quantities, meaning that they can cover a significant area of your roof in just a short amount of time.

Moss and lichen are often compared to each other due to their similarity in looks, with both capable of causing major damage to a roof. However, there is a key difference between them. Moss is thicker and therefore can hold more water than lichen which, in turn, can cause further problems. As moss can hold large quantities of water, this can put additional weight and pressure on your roof. This can lead to expensive structural issues.

Roof Leaks

Inspecting your roof to make sure that it is clean also means that you can spot any problems that could cause further damage such as gaps in the roof that could cause leaks. Cleaning your roof regularly can also ensure that these problems do not arise due to the strength of your clean roof.

Not only can mould become a problem due to an unclean or leaking roof, but it can also lead to ceiling stains due to the moisture from the outside world entering your home. These watery stains are a pain to remove and can be a catalyst for more problems including the growth of mould, rotting framing and sheathing, destroying your insulation, and causing damage to your ceiling in general.

A roof that is not looked after can also have lesser-known problems, for example, ‘shiners’. These cause water ceiling stains that are smaller than those from a gap in the roof as they come from a smaller problem. A ‘shiner’ is a nail that missed a frame so it sticks out on the ceiling in your attic. Any moisture from the roof can condense on cold nails which freeze during the night, causing the nail to look frosted at the bottom. When the attics heat up during the day, the frosted tips can melt and cause stains on the ceiling below. A solution to this is regular cleaning and inspecting of your roof, and also simply clipping off the end of the nail.

Leaks can also be caused by any holes that were man-made on your roof. This includes holes made for satellite dishes, antenna mounting brackets, or vents. These holes are easy to fix, just by filling them in. This point illustrates the importance of checking your roof before conducting any cleaning to make sure that no further damage is caused.


When a roof is left uncleaned, common pests such as bats, birds, insects, and squirrels are attracted to the build-up of moss. These pests often see moss as the perfect home to settle into. While this might be great for them, it can cause numerous problems for your roof and your building.

Birds have an especially strong attraction to roofs that have a build-up of moss. Birds such as pigeons like to find areas to settle near food and water sources, with moss providing both of these things. Birds can then gather in large groups, leading to headaches when their faeces gather all over your roof and their continuous flying to and from your roof can crack your tiles.

Other creatures can be known to squeeze through small gaps on your roof and cause plenty of problems within your attic. Insects such as bees and wasps can easily get through any small holes in your roof and build their nests. This can have damaging repercussions as to create room for their new home they have the capability of removing or hollowing out sections of your roof, causing more problems and costing you more money.

Bee and wasp removal can cost up to £99 depending on the size of the nest or hive and the location. This is a cost that is easily avoidable by inspecting your roof and making sure that it is kept clean and in good condition.

Bats can also cause problems if they decide to call your roof or attic home. Not only can they damage your roof when entering it, but they can also carry many diseases and bacteria which are extremely harmful to humans. Bats are also protected by law, meaning that their removal is tricky and requires specialists to assist you, in the form of the bat Conservation Trust.

The best way to prevent these pests from entering your home and ruining your roof is to ensure that your roof is maintained and tended too. As well as filling in any potential gaps or cracks in your roof regularly, your roof must be kept clean of moss and lichen. This will deter pests from making a home in your roof and will prevent any unwanted damage.

Benefits to Cleaning Your Roof

Aside from preventing the problems discussed above, there are additional benefits to keeping your roof clean that can be considered and discussed. These are benefits that you may have not thought of before as often the roof maintenance and care is an afterthought once an issue has occurred.

Kerb Appeal

We all know that there is something quite satisfying about before and after cleaning pictures. As you can see below, the difference between a clean and dirty roof is remarkable and the after result is clearly a more appealing image.

The look of the outside of your house is equally as important as the inside, and a clean roof can definitely help a house to stand out for all the right reasons. Not only does your roof look nice and clean but it also ensures that you no longer have to clear up moss or dirty water that has fallen onto any cars, driveways, patios, and doorways.

This is, of course, beneficial if you are looking to sell, as prospective buyers are more inclined to look inside a house if they like what they see on the outside. An unclean roof may also put prospective buyers off if they think that the roof looks like it needs to be replaced as that is an added expense for the property.

Even if you are not considering selling your house at the moment, the house pride that you will feel once you have cleaned your roof is worth the time and effort that you put in. A clean roof makes a huge difference to the overall appeal of the outside of the house.

Health Benefits

Dark roof stains are not always what they appear to be. They may look harmless, but that dirt is often caused by algae spores that can grow due to rain or travel by wind and birds jumping from roof to roof. These algae can grow and turn into mould and fungi.

The fungi grow rapidly due to the moisture on the roof tiles from rain or dew, which then causes a rise in humidity which is the perfect breeding ground for more algae, fungi and mould. When this is not cleaned off of your roof, a snowballing effect can occur, with algae, fungi and mould growing exponentially.

Mould can affect anyone, with the effects often being particularly damaging to certain people. The problems caused by spores are especially dangerous for those that are more sensitive than others such as babies and children, the elderly, people with skin conditions like eczema, those with asthma, and people with weakened immune systems, for example, those having chemotherapy.

The growth of all these spores on a roof can be harmful. This is because inhaling mould fragments can cause many health problems including inflaming the airways, nasal congestion, wheezing, chest tightness, coughing and throat irritation.

Even if there are no vulnerable people in the household, excessive mould build-up can still cause problems, including damaging the structural integrity of the house. Cleaning your roof can therefore help to eliminate the growth of mould which can save those in your household any potential health problems, as well as keeping your building structurally sound.

Prolongs the Lifespan

An additional benefit to keeping your roof clean is that by removing moss, algae and lichen, your roof tiles will last much longer. This is because the debris can cause cracks and can loosen the shingles which could lead to an unstable roof and eventually water leaks. By cleaning your roof regularly, the impact on your tiles is severely reduced.

If the tiles are loose and cracked, the roof can appear uneven which reduces your curb appeal, whilst increasing the risk of your tiles breaking and falling off of your roof. By regularly maintaining and cleaning your roof, the lifespan of your roof will increase as the tiles will stay in good condition.

Cleaning your roof also includes applying a coating to shingles that protect them from adverse weather conditions and general wear and tear. This is important as when shingles lose their protective layer, they are more susceptible to hail which can cause damage leading to cracks, and UV rays which means they can be harmed by the sun.

By regularly cleaning and coating your roof tiles and shingles, you can extend their lifespan substantially. You will save yourself the time, hassle and money required to replace tiles through regular maintenance, making it a worthwhile investment.

This Will Save You Money

Repairs needed due to the problems caused by a neglected roof can cause overwhelming amounts of stress, not only because your roof is a vital part of your house but also as the cost of fixing roof issues can be extremely high. Of course, prices will depend on the house size, the complexity of the roof and if there are features such as chimneys to work around. Despite this, fixing your roof is an unwanted expense, regardless of the cost. estimates that the average 2020 cost for a roof replacement in the UK is from £5,000 to £6,000. This estimate is for a whole new roof, hence the large sum, but even if there is only a select number of tiles that need to be fixed it can cost upwards of £200. All of this seems like an unnecessary amount of money to spend when this unwanted cost can be avoided through routine care and maintenance on your roof.

Roof cleaning is also an infrequent cost (see ‘how often?’). By taking the time and money to clean your roof, you can save you frequent and costly expenses because your roof is damaged.

Another way in which regular roof cleaning can save you money is that through the removal of certain organisms can save you money on your energy bills. This is because organisms such as black algae create dark streaks on your roof that absorb heat. The removal of black algae means that your home will be more energy-efficient, in turn, saving you money.

How to Clean Your Roof

Different methods can be used to clean a roof. This depends on the homeowner’s tastes, the type of roof, the tiles, and the resources available. Different types of treatment and chemicals can be used to clean roofs that range in price and have their own pros and cons.

First are a couple of tips that may seem self-explanatory, but if you are new to roof cleaning and have never thought about it before, you may need some pointers to get the ball rolling.

It is recommended that if you are washing your roof you should start from the top and work your way down. This is fairly self-explanatory as it will ensure that any debris, water and chemicals/treatment run down the roof rather than dirt being sprayed up it. This also means that if you are waiting for any solutions to dry then you will already be at the bottom of the roof so that you can get down safely and wait.

Cleaning your roof in the summer months is also a good idea as the days are longer, there is more daylight and any solution can dry quickly which ensures that any moss, algae and lichens will not return.

Different Methods

A low-cost method of cleaning your roof is to use a scrape and brush. This effectively means ‘handwashing’ the roof and is suitable when the homeowner wants to remove small amounts of moss between ‘big’ cleans or if they want to save money. This method also requires fewer materials, however, should only be used when the task is small, otherwise you could end up spending hours on your roof!

Using a pressure washer may seem like a quick and easy way to get rid of unwanted moss, algae, lichen and dirt simply by blasting them away but surprisingly, there is some controversy around using this method in the roof cleaning world.

Pressure washers are very powerful tools that, if used by someone inexperienced can end up with more damage to the roof than to begin with! The large amounts of pressure can damage tiles which can end up costing more money to fix or replace. Not only can they cause damage, but they can strip the colouring of your tiles too. It may seem like a quick way to get rid of unwanted dirt but there are problems with this method due to the sheer power of the machine.

If your roof is made from clay, concrete tiles, slates, asbestos and metal roofing sheets then pressure washing could be for you. If you are not sure it is important to check with an expert to ensure that you will not cause any damage. There is a lot of information online about which method of cleaning would be most suitable for your roof. A pressure washer can be a dangerous piece of kit and should only be used by those who are confident in handling it.

Arguably the most popular method to clean a roof is an alternative to pressure washing, called soft washing. This is, as the name suggests, a less powerful method. Soft washing uses a lower pressure per square inch (PSI) of less than 1,000 on a pressure washer and is usually paired with a treatment to kill any unwanted organisms from the root.

As well as a lower PSI, the head of the hose on the pressure washer will be replaced with a widening tip, which therefore spreads the spray and reducing the risk of causing damage to any tiles or shingles. This also reaches a large space of the roof, ensuring that all crevasses are cleaned and protected from future organism growth. With a wider set tip, the job can also be completed at a quicker rate than if you used a narrow tip.

The process of soft washing usually starts with a quick removal of any moss manually using hand-held tools. After this, a soft wash solution will be applied to the roof. The solution is made from chemicals, for example, Sodium hypochlorite, which is the main ingredient found in household bleach but with an industrial-strength.

The second most common chemical used is sodium hydroxide or lye. This chemical is used for reasons such as to unclog drains and to make soap. There is also sodium percarbonate. This option is the most environmentally friendly and is commonly used as an alternative to bleach in laundry detergents.

All of these chemicals used for soft washing are biodegradable and safe if handled correctly. They are combined with a surfactant detergent which requires the right mixture, this is typically around 12% of the chemical, and the rest of the mixture is detergent. It is important to ensure that the mix is correct. Always read the instructions on the chemical’s packaging to guarantee that you mix the correct quantities to make the correct concentration of the solution.

The result of using a correctly mixed solution will give your roof a highly effective clean. It will kill the unwanted organisms that are on your roof at the root, meaning that is difficult for the organisms to regrow quickly.

Before you start cleaning your roof, it is important to pre-soak the surrounding area where your plants are present. This prevents them from receiving a high dose of the chemical cleaning mixture.

If you wish to be extra cautious with your surrounding plants, you can place tarpaulin over your plants to prevent the chemicals from touching them at all. If you do choose to use a tarpaulin, you should pre-soak your plants anyway, to ensure that no unwanted damage is caused.

This mixture is usually left to dwell to remove the organisms effectively with a low-pressure water spray. Then, a pure water spray is used to wash the remaining solution off of the roof. Any debris from the wash itself will be removed again from the gutters and there you go! A beautifully clean roof that is not damaged from any high-pressured cleaning.

Cleaning your roof by soft washing rather than pressure washing means that there is less of a chance of damage which, when conducted correctly, is a safe and efficient way to clean your roof of any dirt and mess while extending its lifespan.

Chemicals and Treatment 

Different types of chemicals can be used to eliminate dirt from a roof. They range in cost and some are more environmentally friendly than others. It is important to make sure you know what you are buying as, of course, certain chemicals can be dangerous to you and your roof.

Eco-friendly products containing non-toxic chemicals can be used to protect the shingles and tiles and effectively remove any organisms without using harsh chemicals. This method results in instant cleaning and removal, however as the products are more eco-friendly, there is an additional cost for such products.

You can also use the chlorine-bleach solution of sodium hypochlorite which acts like an acid that removes the organisms after a couple of coats. This method is less expensive as the solution can be easily bought online. If you do use this method, you should ensure that you have pre-soaked the surrounding area.

There are, unfortunately, cons to this method as the chemicals can create a strong odour and bleaching your roof often can lead to damages on the shingles due to the sodium content. Should you choose this method, make sure that you use the correct concentration of the chemical and you do not mix it with other solutions. Always consult a professional if you have any concerns.

There are alternative cleaning solutions, such as oxygen-based bleaches that cause no damage to shingles. Particles can also be sprayed into the air which can be a danger to the person cleaning the roof, so make sure that you wear eye goggles and use a safety mask to prevent any harm to yourself.

Remember to Seal It

Roof sealants are used to extend the life on your roof as they add a protective layer to the tiles and shingles, filling in any cracks that may already be there. This will, therefore, add to your roof’s life expectancy as it acts as a barrier from additional weathering, meaning you won’t need to buy more tiles.

We all know how to take care of our carpets, our ovens, and our gardens, but we don’t typically know the ins and outs of roof care. One aspect of roof care that is often forgotten about is sealing. Once you have cleaned your roof, it is important to seal your roof. There are clear benefits to doing this.

The fact that sealing provides a waterproof coating which allows moisture from inside the house (such as from cooking or showering) to escape, sealing provides UV protection for shingles that can be damaged by the sun, there is added fire-resistance to protect those inside, and the prevention of mould growth as sealants tend to have low permeability meaning they don’t stay moist.

Roof sealants are available at most hardware shops, or online. These are fairly inexpensive and are a worthwhile investment, elongating any roof tiles’ lifespan. Apply this after every roof clean, and you should see that your roof tiles become less damaged, and less mould will appear on them. This all saves you time when you do your next roof clean!

Don’t Forget the Gutter!

Gutters provide a safe way to remove waste and rainwater from your roof. Unfortunately, this also means that a gutter can quite quickly become home to debris, leaves and moss from the roof. This means that gutter cleaning is an essential part of roof maintenance too.

It is easy to think that as you cannot see any dirt in your gutter, that there is nothing there. However, this is not always the case. Gutters can fit large amounts of debris in them so that by the time dirt is visible from the ground, damage to your roof and gutter may have already occurred.

If a gutter is blocked, then it becomes difficult for it to fulfil its purpose, meaning water and waste is not safely removed from your house. When water and debris do not drain out of your gutters properly, this can cause additional weight and strain on your roof. This can lead to structural damages to your walls, roof, and foundations.

Not only can gutters become blocked, but over time they can also rust, causing problems such as erosion which will them compromise their integrity and stop its normal function. Rust can simply be removed using a wire brush then cleaning away the debris.

Ensuring your gutter is also clean is a crucial step to cleaning your roof and making sure that both the gutter and roof are functioning normally. A soft wash of your gutter will clean out the debris and also kill them at the roots, giving you peace of mind that any moss, algae or lichens will not return any time soon.

Potential Risks

If you are thinking of cleaning your roof yourself then you should be made aware of the potential risks involved as climbing up onto your roof does bring some danger. These risks are not only for you but also your roof.

When you are cleaning your roof, there is a potential risk of discovering broken tiles, loose edges, or other problems ( Of course, this is a good thing as it means that you can get it sorted, however, it also means that there is potential to make any problems worse by messing with the rest of the roof. Because of this, roof cleaning requires some care and inspecting to make sure nothing is made worse.

There is also potential to cause damage by the clean itself. As mentioned before, pressure washing can cause damage to tiles and shingles, meaning it’s probably a good idea to do ample research before you begin the cleaning process. You can also damage the roof just by walking on or by applying pressure to it, so be sure to make sure that you have inspected for any cracks or loose tiles.

Then there is climbing on any ladders or walking over flat roofs that are a risk in themselves so, as mentioned, it is recommended that checks/inspections are completed to ensure your safety. Do not use a pressure washer whilst working on a ladder, as the powerful recoil of the spray wand can cause you to lose your balance.

When working with any chemicals you should always use gloves. Additionally, make sure that you wear safety goggles before starting any cleaning to ensure that no chemicals or debris get in your eyes. As well as this, when using chemical cleaning solutions, you should wear a face mask to prevent any ingestion of chemical particles. These three pieces of personal protective equipment will help make sure you’re safe from any chemical-related risks.

How Often?

To ensure that your roof is kept in a good condition, to avoid pests, to save money and to keep the kerb appeal of your house, it is recommended that you give your roof a comprehensive wash every three to five years. When you do a thorough clean of your roof, it can stay in a great condition for years, especially if the organisms are killed at the root.

This is different from gutter cleaning, however, which should be done yearly, to make sure that your gutters are in working order and to prevent any damage from debris. This is because gutters are only small and can fill up easily, especially if there are trees in the surrounding area of your house as they can clog up the gutter.


There is no doubt that cleaning your roof is a good idea, even though it may not feel like one at the time! Multiple problems can occur if you do not clean your roof which, as many of us may have never of thought to do this, is rather shocking.

Organisms such as moss, lichens and algae can have a dangerous knock-on effect that can hurt members of our families due to the growth of mould and fungus. Not only are there harmful repercussions for our families but also the roof in general. These organisms can damage roof tiles leading to damage such as leaks.

These leaks also have unfortunate repercussions such as ceiling stains, the development of mould inside the home, and ‘shiners’. Due to the holes or cracks in the roof, there can also be an unintended invitation to all sorts of pests who bring their own delights, adding to your troubles.

Not only do pests add to your potential headache due to hole(s) in the roof, but they can cost a lot to remove as certain pests such as bees or wasps require specialists to remove them as it would not be safe to do so by yourself.

In addition to preventing these damages, there are countless benefits to cleaning your roof. Kerb appeal is a valid reason to want to clean your roof, whether you are in the market to sell or not. Dark stains caused by moss, lichens and algae are not appealing and there is so much pride in having a nice-looking house.

Along with kerb appeal is the health benefits that come with a clean roof. This is because when mould and other organisms are eliminated, everyone in the household, particularly vulnerable people, are safe from the respiratory issues that are caused by mould.

Not only are there health benefits but there are additional benefits to your bank account! Expanding the lifespan of your roof by keeping up with roof maintenance and cleaning every three to five years means that there are no surprise costs. With a bit of TLC, you will not have to worry about your roof falling apart or being damaged due to neglect.

This can all be done following several methods. Based on the information above, soft washing is the easiest and most effective way to clean your roof without causing any damage that will take up more time and money. You should ensure that you have done thorough research on your roof and its material, to discover the best fit for your roof.

When it comes to cleaning your roof, it is a big job, but by doing this regularly you will save yourself time, money, and effort in the future. There are clear benefits that will protect not only the longevity of your roof but will give you peace of mind that your whole family is safe, all because of your beautifully cleaned shingles.