The best way to clean a roof is to use a roof cleaning chemical and let it sit for awhile.
How to wash a roof.
Most contractors don t recommend pressure washing or power washing a roof.
Of laundry strength liquid chlorine bleach and water.
This is because the water comes out too forcefully and can damage the material.
In addition choose a day with little wind so that when you spray the solution it stays on your roof 1 x research sourcestep 2 perform maintenance on your roof.
That ll prevent the cleaner from drying out too quickly.
Spray the cleaner on a section of roof and let it sit for about 15 minutes.
Cleaning roofs is slippery work.
Then spray the cleaner onto the shingles photo 1.
Before you begin it s important to repair loose shingles and flashings to minimize roof damage.
With most good cleaners that s all you need to do.
Before applying the cleaner spray the roof with water to cool it down.
Lightly scrub with a soft bristle brush.
Use the sprayer to saturate a strip 3 feet high x 10 feet wide.
Sunlight and warm weather will ensure the cleaning solution dries too fast to be of any use.
Just spray it on and leave it.
That way you always stand on dry surface and reduce the chance of slipping.
It will rinse off the next time it rains.
Instead soft washing with a garden hose is least likely to chip dent or crack the tiles or panels.
To clean a metal roof wait for a dry overcast day and make sure you have a partner to help you for safety reasons.
The day you perform deep cleaning on the shingles should be cool and overcast.
Start at the lower portion of the roof moving up as you clean each lower section.
Wait about 20 minutes then rinse.
Use a sprayer attached to garden hose that s filled with equal parts chlorine bleach and water.
When you re ready to get started spray your roof using a garden hose with a spray nozzle attachment starting at the top of the roof and blasting downward so the dirty water runs off the sides.