Services:

Moss Removal from Concrete Tile Roofs

Concrete tile roofs are fairly common in the Pacific Northwest. They are typically found on low pitched roofs. They're hung by nails, are thick and cast shadows. The moss finds moisture and nutrients on the ends of these concrete tiles. It will typically grow into clumpy moss. As the clumpy moss grows in size, it may break off and tumble into the valleys or the gutter. Clumpy moss that accumulates in the valleys will slow rainfall and may back up water, possibly causing the roof to leak. More often however, the clumpy moss lands in the gutter where it easily plugs the typical small openings that allows water to enter the downspouts. This causes the gutters to over flow. After the gutters have been cleaned, more moss falls and plugs them again. This troublesome occurence is often the point that the moss problem gets addressed.

Moss removal in progress on concrete tile roof
Photo by Brad Lewis

If you already have moss on your roof, it should be killed first. If you roof is very steep and you don't mind looking at the dead moss, you can let it weather off the roof. However, the dead moss will plug the gutters. So typically you want to have the moss removed and the gutters cleaned.

Moss can be removed from contrete tile roofs by weathering, pressure washing or hand brushing. If the moss is allowed to weather off, then it will typically plug the gutters. If the moss is pressure washed off, then the pressure of the water will blow back up the concrete tile openings and get under the tiles. If the moss is hand brushed off in a dry day, then no damage will occur and then the dead removed moss can be blown off the roof easily. After it is blown off, the gutters are cleaned.

After cleaning your concrete tile roof, you may want a moss preventative applied. I would warn against using zinc sulphate on a concrete tile roof as this will leave a chalky appearance that will nearly stain the composite roofs. It will not come off in the first or second or third rain. So something like a biocide will need to be used. I currently do not offer this service due to not having a product for it, but if you have a product that you would like to try or you sell such a product, please contact me with the contact link above.

Please choose your roof type for more specific helpful information:
   Moss removal from composite/3 Tab shingles
   Moss removal from concrete flat tile roofs