Are your roof tiles ready for cleaning?

What you need to know:

Over time, roof tiles get covered in moss or algae that could become dangerous in the long run. It is important to consider a cleanup before it is too late.

The first day after you have installed tiles on the roof, you are filled with nothing but pride. The elegance they bring to the structure is unmatched. Yet a few years down the road, mould starts growing and in no time, the roofed area of the house starts looking like the shadow of its past.

Cleaning them therefore comes in handy, especially if you want to expand their lifespan. It focuses on killing and removing algae or moss that may have grown on the tiles (shingles).

This is because majorly, algae and moss normally collect over the roof thus affecting the tile performance or even lessening their lifespan.

Most roof tiles are finished with limestone and some components of Asphalt. These chemicals provide comfortable growth of moss and algae on the tiles which necessitates clearing them when seen. This is according to The asphalt Roofing Manufacturers Association (ARMA), a trade association representing North America’s asphalt roofing manufacturing companies and their raw material suppliers.

According to Yani Avramidis, Vice President of Long Roofing, moss has the ability to hold in moisture and divert water, making the wood rot and leak. Due to the fact that they tend to grow in the slots between the tiles, it takes pretty long for the water absorbed to evaporate.

Perks of cleaning your roof  

You get to prolong your roof tiles’ lifespan by removing all the moss and algae that would in this case be eating away your tiles.

The house stays clean and attractive. This is because the roof takes one of the biggest parts in house building. For real estate workers, a roof can determine whether a person will buy a house or not. Keeping it clean therefore will keep one proud of their house.

Cleaning, though, also has its own flaws if not done properly. You can, in the process of cleaning, destroy your roof too.

Pressure washing your roof may be able to remove all the lingering moss but it has its shortcomings too. This is because it may cause damage to your tiles by forcing the water beneath the tile. This will make the tile loose to the floor of the roof where it was attached making them more likely to blow off when the strong wind comes.

This may cost you a lot in the long run, where you may need to replace the tile or do expensive repair.

Hiring a professional cleaner will in this case be a better option since most will include a cleaning solution that kills the algae or moss and keeps the roof clear of them.

 DIY or professional?

However much one is able to wash their own shingles, it is quite risky up there. If not careful, you can unknowingly damage the roof too. It is therefore better to use professionals with the right safety equipment and with knowledge of how to avoid damaging your roof.

According to Saul Mpindi of Mpindi reality properties, they sometimes use detergents which include chlorine bleach to kill the fungi. However, they have to be keen enough to make sure it does not spread anywhere near other necessary plants since the detergents can be unfavourable to them too.

While some water and cover the plants first before starting the cleaning process, others are just careful with the water and the cleaning, making sure it does not spread elsewhere.

Other cleaners just use water in case the chemicals remain in the gutter. “Most home owners tend to collect water for domestic use when it rains through the gutter. Having chemicals lurking in the gutter can then pose a threat,” a worker at Best Choice, a cleaning company revealed.


While some cleaners may charge you per square metre, others will give you a quotation for the whole roof.

Companies vary too. While some will clean at an average price of Shs3, 000 per square metre, others will do that at Shs30, 000.


It is best to leave the cleaning of a roof to a professional cleaning company. They have the right materials to work safely and not cause damage to the roof. Think of a scaffolding and the obligatory safety devices. Another reason for choosing a roof cleaner is his knowledge of cleaning agents. Each type of roof tile demands a specific treatment. When using cleaning agents that are too persistent, the roof tiles will lose their protective layer. This might lead to even more moss formation and damage.