We like to say, “Buyer Beware,” but a lot of consumers just pick what is cheapest. This can royally screw the pooch, so to speak. Check the manufacturer bulletins before proceeding with any home improvement. When it comes to cleaning your house, deck or roof; not every surface can be cleaned the same way. Make sure you hire the most knowledgeable company. In this article, I examine two technical bulletins: Ashpalt Roofing Manufacturer Bulletin (ARMA) Trex Deck Cleaning Guide and the Dryvit Technical Bulletin.
Ashpalt Roofing Manufacturer Bulletin
The Asphalt Roofing Manufacturers Association (ARMA) is a trade organization made up of roofers in North America. They spearhead the research and development within the asphalt roofing industry and as such, has created a cleaning bulletin for informational purposes. ARMA works with shingle manufacturers, lobbyists, the EPA local government to help the asphalt shingle industry grow and thrive.Formed in 1915, ARMA has been involved in the fire resistant shingle trend in the 1970s and the recyclable shingle movement of the 1990s.Today, asphalt shingles make up about 80% of American roofs.
One of ARMA’s publications it the “Algae Discoloration of Roofs,” where the explain what is growing on the shingles and recommend treatment procedures. Gloeocapsa Magma grows on many surfaces, asphalt shingles being an important one, causing dark discoloration and unsightly streaking. Some advancement in algae resistant shingles has been made, but just like gutter guards, each house is its own micro-environment. That means that the pitch, location and age of the roofing material all contribute to how bad the infestation will get. Algae resistant shingles are more expensive than regular shingles and come with a thick warranty detailing ways the manufacturer will not reimburse you if the Gloeocaps magma grows on the roof. ARMA recommends a cleaning method they call temporary and suggest buying algae resistant shingles.
Now, I would compare the cost difference between shingle types and get a quote from a reputable roof cleaner to see which path is right for the house. We live in nature and as such, cannot completely keep life from forming on dwellings. Between the wind and the rain, a shingle roof will only last about 25 years. ARMA is in the business of helping roof shingle manufacturers, not in keeping those shingles free and clear of algae. There must be a community or organization of roof cleaners that has cropped up to tackle this problem!
Dryvit Bulletin: Cleaning and Maintenance

Trex Deck
One of the most popular decking alternative, Trex Deck is a composite material that holds up better than wood. Like any porous material, it will trap moisture, dirt and grime. Unlike other manufacturers, Trex supplies a detailed cleaning guide based on the type of stain/dirt. They specifically do not recommend the use of a pressure washer or sandblasting as this will put lines in the material.
For More Information
- Roof Cleaning Technical Bulletins
- List of Technical Bulletins from various manufacturers under research page.
- Drvit Bulletin: Care and Maintenance
- Direct link to the Drvit Technical Bulletin
- Asphalt Roofing Manufacturer Association
- ARMAs Website
- Trex Deck
- Trex Decking Website
- Morgan Clickner
Office: 410-482-4367