Instead gently pray the roof down with a mix of half bleach and half water.
Cleaning mold off asphalt shingles.
1 4 cup tsp trisodium phosphate or other heavy duty cleaner don t use a cleaner that contains ammonia or is not recommended for mixing with bleach as it can result in poisonous chlorine gas pour the ingredients into a pump type garden sprayer mix well and spray.
Asphalt shingles are designed to withstand rain not the force of a power washer.
How to clean roof stains wash your shingles where the sun doesn t shine.
Never use a pressure washer to wash or rinse shingles.
Not to worry though because you can clean the mold off with basic household bleach and save your roof long before you need an expensive replacement.
Do shingles on your north west or other shaded roofs have streaky moldy stains.
Never use a pressure washer to clean an asphalt shingle roof as this w ill cause granule loss and very likely premature failure of the roof system.
Make your shingles last longer.
Let the mixture sit on the roof for 20 minutes before you rinse it off.
Black streaks on the north and west facing and shaded.
The concentrated jet will scrape off the small pebbles on top of the shingles and reduce their water repellency which will only make your mold situation worse.
Step 3 applying asphalt roofing shingles containing a copper additive in their surface granules is an option.
Doing so can damage your asphalt shingles.
You could replace all the roofing with new shingles dark enough to disguise the staining or with shingles laced with copper granules which are lethal to algae.
But that would only make sense if the shingles were worn out.
Mold stains can form on roof shingles that are in permanent shade.
Installing zinc strips under a row of shingles near the ridge of the roof will prevent mildew from forming.
In severe cases it may take more than one bleach treatment to kill all of the moss.
Here s how to clean the.
Extensive mold growth can also expose the interior of your attic or crawlspace to mold spores carrying the problem over to the inside.
Moss will loosen over time and may be removed with a leaf blower.
These stains will discolor your roof and damage the shingles over a period of time if left alone.
The mild chemical reaction caused by rainwater coming in contact with the zinc inhibits the growth of mold and mildew.
Generally you ll need to unscrew the tops of the spraying device and the cleaning agent fill the spraying device then.
For large expanses of an asphalt shingled roof use a long handled scrub brush made for cleaning gutters and roofs.
Don t use a pressure washer to apply the cleaning agent.
If you have a consistent problem with mold growth on your roof consult a roofing professional.
