Asphalt Shingle Cleaning

Midwestpro · Posted: Sun Oct 21, 2007 12:09 pm Post subject: Asphalt Shingle Cleaning

Roof cleaning is a subject that gets a lot of lip service. There is a lot of debate whether pressure washing roofs does more damage than good. Through my research and experience I can tell you that yes it does cause more damage than good. You never want to use a pressure washer to clean asphalt shingles. The pressure will blow the shingle granules off the roof which are there to protect the shingle. Doing this will definitely lessen the longevity of your shingles.

First of all, why is cleaning a roof necessary? The most common reason to clean asphalt shingles is due to an airborne algae called gloeocapsa magma or roof algae. This alga is spread down the roof by rain causing black streaks. If not cleaned off the algae will spread across the whole roof and won't allow the shingles to reflect heat causing them to fail prematurely, costing you money.

So how do you clean shingles without harming them? There are guidelines and techniques that are recommended by most of the major shingle manufacturers. By using these recommended low pressure techniques, shingles suffering from roof algae can be cleaned properly without damaging the shingles.

TedO · Joined: 25 Oct 2007 Posts: 4 Location: MI

A year ago we had a friend of a friend pressure wash our roof. We now know that wasn't the best choice as it probably caused some damage. We have some black stains starting to show again and want to have it cleaned. Will the low pressure method do anything about the staining returning so quickly? Thanks Ted.

A-PLUS · Posted: Thu Oct 25, 2007 5:45 pm Post subject:

Ted, the low pressure method is the only go. The last method just blew the algae around your roof and it did not kill the algae, that's why the
stains returned so quickly.
Having your roof low pressure washed with the proper cleaners to kill the algae and a low pressure rinse, should keep your roof looking good for
3 to 5 years.
I hope this helps.

Midwestpro · Posted: Fri Oct 26, 2007 11:31 am Post subject:

I agree with David, the algae didn't return, it never left. The pressure using contractor probably didn't use any cleaners or he used the wrong ones so the algae was never killed.

Jerry · Joined: 04 Dec 2007 Posts: 1

Can anyone please provide the name of a roof cleaner and where it can be purchased? It would be for fiberglass/asphalt shingles in Louisiana. Thanks

Midwestpro · Posted: Tue Dec 04, 2007 5:22 pm Post subject:

Jerry

I would use what the major shingle manufacturers recommend to clean shingles.

http://www.iko.com/misc/ArmaPdf/217-RR-89rArmaAlgae.pdf