NFT: Roof Moss/Mold removal

Prepackaged products both at Costco and the big box stores. Come in their own house end sprayers. Sorry the brand names escape me but I've used two different ones and they both work great.

Spray them on then just be patient. House I bought had thick deposits on the shaded parts of the roof. 3 -6 months after spraying all gone no issues.

Assuming asphalt shingles, whatever you do don’t power wash or scrub. You’ll damage the roof.

I would try a specific cleaner for the project that’s less harsh rather than bleach, etc. a product like Wet and Forget, which you spray on and don’t have to rinse. Do it on a cloudy day so it doesn’t evaporate too quickly.

Asphalt shingle....knew i forgot something..

Thanks for the input. Amazon reviews for Wet and Forget are hit an miss...which is why I started looking a little deepter

...and mixing it yourself with a surfactant or an off the shelf product like 30 Second Clean will take care of algae/mold. Moss you'll need something different like Wet N Forget (which also kills mold/algae but over time). I used the Wet n Forget on a retaining wall and other areas on my patio after I removed some shrubs and it actually worked really well on the moss. The 30 Second Clean is just a dilution of bleach but has a very effective surfactant - works really well on vinyl siding.

If you have larger tufts of moss you may need to scrub them off gently with a brush.

You can also add a zinc strip tucked up on a row of shingles near the ridgeline of the roof which will prevent it in the future.

TSP is the standard you can get in the stores. It has mixing instructions on it for solutions for killing mold.

Just not uphill.

Ryan...Zinc strip is a new one. I assume that would be a full length strip?

Bill T. Thanks...I just happen to have TSP on hand for a different project

Giant John. It almost needs a lawnmower at this pointy

In comment 14910933 Ryan said:

Quote:

...and mixing it yourself with a surfactant or an off the shelf product like 30 Second Clean will take care of algae/mold. Moss you'll need something different like Wet N Forget (which also kills mold/algae but over time). I used the Wet n Forget on a retaining wall and other areas on my patio after I removed some shrubs and it actually worked really well on the moss. The 30 Second Clean is just a dilution of bleach but has a very effective surfactant - works really well on vinyl siding. If you have larger tufts of moss you may need to scrub them off gently with a brush. You can also add a zinc strip tucked up on a row of shingles near the ridgeline of the roof which will prevent it in the future.

Yes, I saw that last line on an episode of This Old House!

You put it on the top of the roof (carefully, with nails), so that rainwater comes off it on both sides, to naturally repel moss.

Use a bleach mixture to get rid of the existing moss initially. Brush off the loose moss first, then let the bleach do its work. The reason moss grows on the roof in the first place is the lack of sunlight, so the guys say.

Not that this is a big deal but it will prevent it in the future.

The stuff is magic. The guy who installed my roof told me about it. Get the concentrate, dilute it into a good sprayer, and spray it on your roof. Done.

In a few weeks your roof will look like new. I live in a wooded area, and I apply it once per year.

And they made very little difference.

they lose their effectiveness after several years and so plan to be periodically replace. I've also seen sloppy installs where the strip is not properly fastened and it separates from the roof, especially during high winds. Pretty unsightly.

I second the use of a sprayable solution in most applications except for really bad moss/mold/mildew problems.