Wet and Forget for asphalt shingles

Does anyone have any experience with the “Wet and Forget” product that is supposed to clean lichen off an asphalt shingled roof?

The manufacturer doesn’t really say anything about when you should see results. I see some people like Bob Villa and others who recommend it, but nobody says anything about when you should see results. I saw one review by a guy who said it took a year! But he was happy.

I know it obviously depends on how much lichen is on the roof, but it seems suspicious to me they don’t say anything about results over time.

I saw another review, but that was by roofing contractors, who said it really doesn’t work very well - or maybe not at all, I don't remember. I have a backpack sprayer and from a ladder I sprayed some vinegar-water mixture and I think it did some good, but that left a lot still remaining, and you have to go up on the roof later and brush at it to remove the lichen.

I’d like something I could spray and then rinse later with a hose if there is such a thing. I’m late elderly now and I turn chicken when I have to get up on the roof –lol.

I was just wondering if anyone has experience with ‘Wet and Forget”.

Any thoughts greatly appreciated.

 

I have used Wet-And-Forget on my unfinished redwood deck to remove a greenish algae/moss. I usually brush it when wet with a stiff bristle push broom and then hose it off. In a day or two the deck "bleaches" to a reddish tinge. The treatment lasts for one season. I have also used Oxyclean in solution the same way with similar results.

Brushing (brooming) asphalt shingles will damage them so you should just apply Wet-And-Forget and let nature take its course. It will take time and you should probably re-apply after 6 months.

 

I use it on two of my north facing roofs. I started using it early to control algae and before anything big like lichen could start growing. I re-apply about every two years preventatively. If you actually have lichen on your roof I don't know of any spray and forget treatment that will remove it. It might kill the lichen but it will remain on the roof and be a host for algae, moss and lichen to return rather quickly. I would treat with a wet & forget or a bleach solution. Then pressure wash to mechanically remove the lichen. You'll have to be careful though as it's a balancing act between removing the lichen and damaging the roof. If it's a bad infestation you may not be able to remove it without damaging the shingles.

 

Thanks 2john and PilotDane.

I think I see now, this is a longer term treatment than I thought and will take some time.

When I did some brushing after I did the vinegar-water treatment I looked carefully at what was coming off the shingles when I brushed. I couldn’t see anything that looked liked asphalt granules or anything like that coming off with then lichen when I brushed. I was intentionally looking for something like that. It looked like just the lichen was coming off and nothing else. But I could be wrong.

But I won’t do any brushing for now. I’m going to use the “Wet and Forget” and do the “forget it for a while” and see what happens.

@PilotDane

I do see many people suggest pressure wash but some others say don’t do it on an asphalt roof. But I can see how it could be just subjective risk-benefit as you suggest and a balancing act as you say – since that lichen will ruin the shingles anyway if you don’t do something about it.

If I can ever get my camera to work again (lol) I’ll post some pictures and maybe if you guys have time you could tell me how bad you think the problem is.

Thanks again for the help guys.

 

I've pressured washed a few roofs for realtor sales. Not something I would recommend. Pressure washing a roof can make it look nice but I'm sure it takes yrs off the shingles life. I'd feel better about lightly brushing if that's enough to remove the worst of it.

 

Thanks mark. Another good piece of information for my storehouse. Appreciate it.

 

I wish I would have taken "Before" pictures - but I didn't.

But the "Wet and Forget" really worked. I think it was last fall I put it on the roof and now the lichen is now gone. I am going to apply it again soon. Seems like pretty good stuff.

I would recommend it.

(Forgot to say I got up on a ladder with a backpack sprayer and was able to spray the entire roof - except for one part. I had to get up on the roof for that one section with the backpack and spray.)

 

Glad to hear that it worked...

In a year!

And that you did not "forget" to let us know.

 

Thanks 2john!