What’s the best way of cleaning a roof?
Why should I clean my roof?
Over time, dirt, moss and algae can build up on your roof, covering your tiles in a thick layer of green. In order to keep your home free from damp and retain an efficient roof with good water run-off, it is important to keep your roof clean and in good condition. We would recommend that you have your roof cleaned every three to five years, depending on how quickly moss and lichen build up. If your home is close to large trees, or in shadow for much of the day, then it’s likely you will need to have it cleaned more often. There are a number of ways in which you can have your roof tiles cleaned, but which method is best and which should you definitely avoid?
Here at CleanMaster we are always on hand to offer help and advice, and we’ve created a quick guide on the best way to clean your roof as well as why you should never have your roof pressure-washed.
Roof cleaning methods
There are many methods of cleaning a roof, all of which have their advantages and disadvantages. These are the 5 most commonly used ways to get rid of moss from roofs.
- Manual scraping.
A simple yet very effective way of cleaning roof tiles is to scrape off the moss, algae and dirt by hand. - Roof Pressure Washing.
There are many roof pressure washing companies out there that will clean your roof. This is usually the cheapest method of cleaning your roof – also the most likely to cause damage. - Softwashing / Bleach (aka Hypo)
Bleach is commonly used after a manual scrape of of a roof to give an instant clean. We are not fans of softwashing roofs even though there is very little chance of damage to your roof following manual roof moss removal. The biggest risk of softwashing is airbourne sodium hypochlorite (bleach), as the softwash solution is sprayed onto your roof particles are carried by the wind with no control where they land – potentially causing harm to the roof cleaning contractors themselves, passing pedestrians & animals. If the chemical comes into contact with any surface other than your roof then it has the potential to cause irreversible damage, items most at risks would be garden plants, garden furniture, wooden window and conservatory frames & convertible car roofs. Softwashing your roof correctly will give a perfectly uniformed clean, with the result visible on the same day as the removal of roof moss is carried out. Softwashing certainly has its place in the external cleaning industry but we feel that the rooftops of domestic homes is certainly not the place – just our thoughts though! - Roof Steam Cleaning
Steam cleaning can be carried out safely on certain roof tiles. We assess your roof and decide what we think is the best procedure to clean your roof . This type of roof cleaning should always be carried out under very low pressure with a low flow rate of around 6 -10 ltrs per minute heated to around 140 degrees. Steam cleaning will leave your roof beautifully clean immediately after cleaning has finished. - Biocidal Roof Wash
This is our most popular method of roof cleaning. Manual roof moss removal followed by a biocidal roof wash is the most gentle and long lasting solution to cleaning your roof – especially when carried out entirely from cherry pickers and mobile access towers as opposed to roof ladders.Your roof moss is scraped manually from your roof tiles before a biocidal roof wash is applied. Once applied the roof wash kills any remaining living organisms on your roof, including moss spores and lichen. Over a period of 3 to 6 months your roof tiles then return to somewhere near their original colour as the surface dirt is lifted from the tiles by the biocide combined with weathering. The biocide then repels future moss growth for 5-10 years or even longer in some cases.
The best way to have you roof cleaned.
All of the above methods of cleaning have advantages and disadvantages. We have developed a cleaning method combining two or more of these methods that maximises the effect, reduces the risk and provides long-lasting results. We start by scraping off the moss, algae and dirt by hand. Once the bulk of the debris has been removed, we may recommend gently steam-cleaning the roof to remove all the smaller particles of dirt and vegetation. The low-pressure system of a steam cleaner does this in a safe way without causing any damage to your roof. Once this has been completed, your roof will look like new. To keep your roof cleaner for longer, we then recommend safely applying a biocide to inhibit future growth of lichen, algae and moss. This application also ensures that any mould, algae and moss hiding in cracks and crevices is treated and will be killed.
Why we believe that you should never have your roof pressure-washed.
A widely used method of cleaning roof tiles is to pressure wash them. However, there are four important reasons why we believe a roof should NEVER be cleaned in this way.
- Using a high-powered pressure washer can cause damage to your roof. The strength of the water jet can crack older tiles, resulting in expensive repairs.
- On other tiles, the water jet can remove the factory finish, resulting in a much shorter lifespan of the tile and requiring premature replacement.
- There is the risk of getting water into the roof/loft space when using a pressure washer, as the water jet will find any small holes, cracks or weaknesses in the roof tiles or felt.
- Cleaning your roof with a pressure-washer may invalidate any manufacturer or builder guarantees that currently protect you and your home.
Want a quote to have your roof professionally cleaned by us? Contact us for immediate attention.