treating algae stains on roofs

Anyone have experience using the spray and leave algaecide products on stained roofs?

Many years ago i used some on a rental and after 30 days the black and green stains were gone.

Local guy asked me about it as his roofer friend said he does not recommend, claims it hurts the roof

The one product I’ve heard of is called “Wet and Forget”. I Never used it, but there is a nationally syndicated radio show (The Carey Brothers) that talks it up at least once per month.

Sure do they used it on this roof

Just kidding the insurance adjustor looked at this roof last week and said it had wind damage only but not enough to warrant replacement

I don’t know about spray and forget it but tsp does a good job

Looks like its still able to hold out water to me Charlie… Whats the problem?? Lol

Thanks chris, thats the product ive heard about as well on Gary Sullivan when he has the roof guys on.

TSP…hmmm… Ill look into that


You gotta have some seriously hot wind there partner…just sayin…

sorry George no experience with the spray and leave…

I recommend installing zinc strips.
Old school but works.

I tried that stuff, I don’t remember what happened:D:mrgreen:

just pressure wash it george! that should make a big difference.:p:p:p

Would you recommend a 5,000 psi washer with a 15 degree tip and start working from the eaves heading up to the peak? :p:mrgreen::shock:

I have used Spray and Forget on my own home. Roof, siding and concrete. I was pleasantly surprised by the results. In some areas of the concrete, results were immediate. Siding and roof took about three days before the growths turned brown and start to fall off.