Realty.com

Expert Advice

Cleaning Asphalt Shingle Roof

A: Your question about discoloration on your roof is a good one

that we hear a lot.

There is no recommended solution for “oak” stains. However, according

to the MSA (Master Shingle Applicator) manual published by Certainteed

Roofing Products, the following is suggested for fungus or algae and

should lighten oak leaf discolorations.

* Mix a solution of 1 part chlorine bleach, 3 parts water, and a

pinch of TSP (Tri-Sodium Phosphate.) TSP can be purchased at most home

improvement stores. Before applying the mixture you may also want to

cover any plants or shrubs around the perimeter of your home to avoid

damaging the foliage.
*

Apply this solution gently to the surface of the roofing, being

careful to avoid damage to other parts of the building and its

surroundings.
*

Avoid scrubbing as well as other physical contact with the roof

because the friction may loosen and remove granules that coat the

surface of asphalt shingles. Work from a ladder whenever possible,

or use “walkboards.”
*

Finally, rinse the bleach solution from the roof by gently spraying

the surface with water.
*

Observe all possible safety precautions when working on or near the

roof. Besides giving special attention to ladder safety, be advised that

the solution application and rinsing process makes the surface of the roof

slippery and therefore hazardous on which to walk.

The effectiveness of the cleaning and bleaching techniques is temporary,

and discoloration is likely to recur.

CAUTION: High-pressure washing systems for algae removal should be used

only by reliable professionals because incorrect application can result

in removing granules and shortening the life of the roofing system.

This information is brought to you by Will and Kathy Babin of Superior Roofing in San Antonio, TX.

If you don’t have the proper ladders or walk boards and/or decide it is

too risky to climb on your roof, you may return to our site at:

http://www.servicemagic.com, type “Find a Roof Cleaning Service” into

the search box and submit a service request so we can match you with the

ideal service professionals in your area.