Long-term moss infiltration on your roof can destroy the integrity of your shingles and take years off your roof's life. It will also invalidate your shingle warranty as moss removal is a maintenance item.
However, it is good to know that it's not always necessary to replace a roof if moss is growing on it. It is possible that the shingles have not yet been damaged and simply need the moss removed.
Have Moss Removed Sooner Rather Than Later
Moss grows into the structure of a roof shingle and weakens it. On an asphalt roof, moss can cause the granules on the shingle to protect it from the sun, to fall off. On a cedar shingle roof, moss keeps the wood damp for an extended length of time and thus accelerates the rotting and disintegration of the wood.
Therefore, to prolong the life of your roof, it is best to remove moss as soon as you notice it.
The Moss Removal Process - Always in the Summer
Moss removal must be done properly in order to prevent a roof from being further damaged.
The first step is to kill the moss before attempting to remove it. This must be done in the dry season. There are some non-toxic products that can be sprayed on to kill moss. After a few hot, dry days the moss will die and the roots will release from the shingles. The moss can then be washed off or lightly swept off. It is important not to use a lot of force when removing well-established moss because the roots will be embedded into the shingles and will cause damage when coming off.
Other Moss Tips
- Moss removal should be viewed as a maintenance function. Just make sure you get a professional to do it so you don't damage your roof or void your warranty. Reliable, reputable roof professionals will guarantee their work and have full insurance.
- People living in North Vancouver and West Vancouver must especially watch out for moss as it is so common and prevalent in these areas simply due of the wet weather.
- Moss will always build up more on the north side of a building.
- There are products like Zinc strips that can be applied to help prevent moss build-up. This approach will meet with some success but it does not work 100% in all situations.
- Some shingles are advertised as "algae resistant". However, they do not prevent moss so don’t let anyone try to sell them to you as a way to prevent moss buildup. They do work for algae growth which really just discolours the shingles.
- On flat roofs, zinc pellets work very well to reduce moss growth.
If roof moss is a problem for you and your home, Absolute Roof Solutions has the trained staff to remove moss safely and quickly from your roof.
If the moss does return, do not rely on harsh chemical treatments or dry spells to kill it, you need a roof cleaning expert to handle your roof.