What are you guys seeing in this pattern of growth? It appears to have a very heavy concentration in the middle and then the imitation shake siding has what appears to be patches of heavy infestation and staining.
It just seems like a strange growth pattern and I know some of you guys have seen it before, so we just wanted to offer a bit more help to the homeowner about the conditon of the siding in particular.
In our proposal we made it clear that once the siding is clear, there may be a dye lot issue that is revealed.
-- Edited by Steve Salley on Tuesday 8th of April 2014 08:04:19 PM
One thing I can see is the siding came from two different lot numbers. I'm not sure if there was a repair to the left end at one time or the contractor just had two different lots.
It doesn't look like there is enough overlap from one piece to the next either. Mainly where there algae staining is in the middle of the porch roof. They may be getting moisture behind the siding there, trapping the moisture and creating a constant drip on the roof area.
Be careful if it is Nail-lite brand imitation shakes. There was all kinds of issues with that siding years ago. You could walk up to it and put your finger through it. It would just crumble into pieces. We replaced tons of that stuff for a big apartment complex.
That looks like what we call "naillite' siding. that is most likely a flaw with the siding. generally when you see the pattern that follows the edge of the siding piece it is a problem with the siding itself not the infestation. Ive seen this on the newer vinyl shakes.