
Have you perhaps noticed dark and unsightly marks on your roof? These are actually algae called Gloeocapsa Magma, more commonly known as blue-green algae. They tend to develop in shaded and hidden areas of roofs, where vegetation is dense and water can accumulate, as well as on parts of roofs facing north.
It’s not just an aesthetic issue; these algae represent a danger to the very integrity of your asphalt shingles and cause premature deterioration of your roof.
Green moss buildup can also be problematic for your roof. This type of moss absorbs moisture during downpours and retains it, creating an environment conducive to mushroom growth. Consistently high humidity and the proliferation of fungi cause asphalt shingles to deteriorate, including lifting, and can eventually lead to costly leaks.
During the work, we apply an antifungal solution to the roof in order to eradicate any organic presence on the asphalt shingles. Our confidence in the effectiveness of our process means that we offer you a two-year guarantee against any reappearance of fungus.
The Net-O-Pression team offers a pressure-free, friction-free roof cleaning service, approved by asphalt shingle suppliers, guaranteeing you a roof in perfect condition.

Have you perhaps noticed dark and unsightly marks on your roof? These are actually algae called Gloeocapsa Magma, more commonly known as blue-green algae. They tend to develop in shaded and hidden areas of roofs, where vegetation is dense and water can accumulate, as well as on parts of roofs facing north.
It’s not just an aesthetic issue; these algae represent a danger to the very integrity of your asphalt shingles and cause premature deterioration of your roof.
Green moss buildup can also be problematic for your roof. This type of moss absorbs moisture during downpours and retains it, creating an environment conducive to mushroom growth. Consistently high humidity and the proliferation of fungi cause asphalt shingles to deteriorate, including lifting, and can eventually lead to costly leaks.

During the work, we apply an antifungal solution to the roof in order to eradicate any organic presence on the asphalt shingles. Our confidence in the effectiveness of our process means that we offer you a two-year guarantee against any reappearance of fungus.
The Net-O-Pression team offers a pressure-free, friction-free roof cleaning service, approved by asphalt shingle suppliers, guaranteeing you a roof in perfect condition.

A 5-star roof cleaning service
The highly recommended roof washing company
in Valleyfield and Vaudreuil-Soulanges.
I am extremely satisfied with Patrick’s work on my house; his attention to detail, his level of communication and the overall visual impact on many aspects of my home leads me to say that I highly recommend his services! Thanks again Patrice!
Very nice result and at a good price. I strongly recommend it. Thank you again I am very satisfied 🙂
Very satisfied with all the work accomplished. It’s a big change that increases the value of my property. Thank you and I recommend this company without hesitation!!
Very professional service, excellent work, my house is now like new! I can’t believe it! Patrick is very nice and excellent price too! I am very satisfied and I recommend it to you! You will not be disappointed! A big thank you Patrick!
Fast, efficient and just Wow service!!!!! I really recommend them.
Super service, deep cleaning and well done BRAVO I recommend without any hesitation at a more affordable price.
Great service from Patrick! My house is like new, and what’s more, he washed our 2 cars. I recommend it to you!
The before and after is truly surprising. I didn’t think my house could return to its glory days. Really satisfied with the exterior cleaning.
Thank you very much for your excellent service! My house needed a deep exterior cleaning and thanks to your magic, you managed to make it shine like a new house. Thank you very much and I strongly recommend everyone to choose your quality service.
I had the exterior of my house cleaned by Net-O-Pression and the result is impeccable. Good value for money. Patrick is very friendly and courteous. I recommend his services to you.
He did an amazing job cleaning the exterior of our house, our house hadn’t been cleaned in over 30 years, it looks brand new. I highly recommend everyone to use this company. Thank you for your excellent work.
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Some achievements of
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Discover our know-how in action through these Before/After transformations.








FAQ
Some questions about our roof cleaning services
When should you clean your roof and how often?
It is recommended to clean your roof at least once a year. This frequency may increase if you live in an area with frequent rainfall or surrounded by dense vegetation. The best times to do this are in spring and fall, when temperatures are moderate and precipitation is less frequent.
Why is it sometimes better to call a professional for roof cleaning?
A professional has the equipment and expertise to carry out effective cleaning and treatment without damaging the roof. In addition, it can identify and repair possible damage that could worsen without intervention. The cost of professional cleaning generally ranges from $15 to $30 per m2, depending on the initial condition of the roof and the treatments required.
Can you clean your roof yourself and what equipment is needed?
Roof cleaning can be done yourself for regular tasks like cleaning gutters. However, for larger cleaning and treatment jobs, it is recommended to call in a professional. Working at height requires safety equipment such as non-slip shoes, a safety harness, and a special roof ladder. A stiff brush may be enough to remove plants, but using a high-pressure cleaner is not recommended as it can damage the tiles.
What products and techniques should I use for roof cleaning?
Avoid using bleach or chlorine, which can damage the tiles. For moss removal, water-dilutable products are common, and for water-repellent treatment, make sure the surface is clean and dry before application. There are preventive or curative moss removal products depending on the situation of your roof.
What are the risks of improper roof cleaning?
Using inappropriate techniques such as high pressure cleaning or using aggressive products can make the roof porous and damage the materials. Additionally, untreated moss and lichens can regrow and cause long-term structural damage.