The Whole Roof and Nothing But The Whole Roof...THAT is the question!?

If the algae/mold is about 100% on the North facing slopes of the roof, why would it be a good idea to clean the entire roof? If the customer request you ONLY clean the algae side of the roofs, what response & logic are we responding with to clean the entire roof? I get it that the algae is air-borne & can spread, but I just have not seen it on any other side of the roof but the Northern sides (I get why that is). Feedback?


I frequent Dallas about 3 times a year. Gloeocapsa Magma did not appear in strength in the Metroplex until about 5 years ago. It is actually a bacterial infection that does not have the warmth and moisture requirements of algae. You are seeing on the north and west exposures of the roofs there because the infection takes between 3 to 5 years to bloom in enough force to been seen and the colonies are thick enough.

The sequence we see in the South East that roofs become stained is first the north side, then the west, followed by the east and the south side will be the very last side to stain unless there is a tree or something that created shade on the roof.

As DFW’s infection of Gloeocapsa Magma ages the other sides of the roof will stain. Roof cleaning is very much like pest control. If you were only seeing roaches in one room of your house you wouldn’t just treat one room but the whole house.

I started the chemical roof cleaning industry now called Soft Washing back in 1991. My companies have cleaned in excess of 50,000 roofs. All through the 90’s I traveled to and from DFW looking for dirty roofs as I spent time there. My wife and I attended college at Abilene Christian University & we have family in the Metroplex. I always tried to explain what I did for a living but until about 4 years ago didn’t have any examples of a dirty roof to show them.

Can you believe there are roof cleaning companies in San Antonio now as well??? Almost 2/3 of the US has a roof staining problem now! I get emotional sometimes when I think about how many people are out there making a living off of an idea I had 20 years ago.

Hope this helps. Call me anytime. 407-832-1108


There could be algae on the rest of the roof, it just hasn’t grown enough to become visible. If not treated there is a possibility that it could migrate back to the north facing slopes, where the conditions are right for it to grow quickly. I think I would do a partial, I would just make it very clear that you don’t recommend it, and that the algae could return quickly


lol I just said I cant believe there are roof cleaners in SA! NUTS! SA is so arid and gets so little rain its completely mind blowing the stuff is there now!!!

THANK YOU for this education. Is similar to what I was thinking but wanted some verification from the experts before these statements coming out of my mouth to prospects & customers. I’ll take you up on that phone call someday! Thanks AC & Larry!

Think again my friend. All the neighbors will remember is YOU cleaned the roof a few months ago, and it is dirty again. They will never know your customer was too cheap to do the whole roof, and nor will your cheap azz customer tell them either.

That is very true. Same reason why I don’t offer an alternate to my full-service window cleaning. If I had separate pricing for “glass only, general clean” my name would still be associated with what I would consider cut-rate service.

The whole roof. Once you are there and set up, it doesn’t actually cost you much more in product nor does it take you much more time to treat the entire roof, so partial roofs are not even an option for me. The only exception would be a multifamily or duplex - I wouldn’t leave a potential client out to dry just because of the stupidity of their neighbor.

When you partially clean something, it looks like you partially cleaned it. The roof, the whole roof, and nothing but the whole roof. Unless your doing the house too.

I agree the whole roof!