Moss Green Color On House: Will Cold Temp's Kill It, And The Color ?

[Robert11]

Hello:

Have a typical colonial, painted white.

The somewhat shady side of the house has a few good size patches of very light colored green colored moss on it. (I assume it's moss, but perhaps fungus, algae, or... ?)

No big deal, but not too happy with it.

Live in New England.

In a few months will be real, real, cold up here.

Questions:

a. Will that kill the moss ?

b. If so, when "dead", will the green color go away ?

Reason I'm asking is that we will be re-painting the house in the Spring, and if the green color will actually go away, will just wait until then.

Thanks, B.

[Edwin Pawlowski]

----- Original Message ----- From: "Robert11"

Yes.

Yes, it will turn a gray color. Maybe dark gray.

It has to be cleaned before you paint. Spray it with a bleach solution, brush it and rinse away. Why not take 15 minutes now to have a better looking house?

[Norminn]

We have mildew/mold in Florida that comes in several colors - red, green, black. Grows best in areas shaded by structure or plants. Cleans up very nicely with 10% bleach and water solution. That is PLENTY strong. Don't want to slather that on any metal parts. Don't know about cold killing it because we don't have cold. Even if it is killed by cold, the spores are everywhere and start growing very quickly in the right conditions.

Thinning trees and shrubs might help, or pruning so they are not as close to the structure. Just scrubbing off soil once a year or so might help. Main reason semi-gloss paint is preferred around these parts, as it offers less grip to stuff that grows. Anything here that stands still more than five minutes will rust and/or grow mildew.

I doubt you have moss growing on the house, but if you do you probably have some real rotten wood. Mildew has to have some organic food to grow on, so cleaning helps prevent growth. We cleaned up some of the landscaping to keep it away from the building, and haven't had any noticeable mildew since. Also repainted, but nothing fancy as far as mildew preventative. If you paint over it, without killing it, it is likely the paint will fail in those areas.

[hallerb]

be certain to use resistant paint, that has copper and other chemicals to prevent regrowth

[Joseph Meehan]

The above is likely the best advice of all.

[k]

I have this problem all the time, and on the North sides. I fill a sprayer with 1/3 liquid laundry detergent, 1/3 bleach, and 1/3 water, and I spray it on from a spray bottle, the kind you squeeze (like windex). After a few minutes, I hose it down, and repeat if necessary (which it usually isn't).

The green will come back eventually, and it will come back after you repaint too, but this is a painless fix. I just did the front of the garage yesterday, and spent a whole half hour at it.

You mentioned that your house is white. If it weren't, I'd try it on an out-of-the way spot first.

Keith