Originally Posted by
Scott Patterson
That's just blasted algae growing on the side of the house. Spray with a commercial siding cleaner and then wash off with a garden hose. End of story.
I was considering it "mildew", but, then, "mildew" and "algae" are basically the same, right?
Now if the substrate is rotting along the base, it sounds like the siding is not finished properly with a "J" channel along the bottom of the siding or it is too close to the ground.
Or, how about no WRB behind the vinyl siding? Water does get past vinyl siding and is supposed to have a way to drain out, maybe the water getting past it is not being allowed to drain out, thereby rotting out the unprotected wood behind it.
Is 'wood' considered a WRB? If so, then it may be allowed, but that may still be the cause.