My carpenter put up a covered porch...stairs going out on either side...it's about 3ft off the ground with half rise stairs. Built over limestone gravel. The stairs and supports on the east side of the porch are all rotten and need to be replaced. They seem to have this white thick mold growing on them. Any ideas as to why this is happening? This is fairly a new build...maybe 3yrs old. It's all pressure treated lumber....I'm hoping this doesn't happen to the whole structure.
Re: Rotten stairs
There is mold that grows on steel.
The best way to get rid of the mod is to control the water. If this is on the north side of your house this may be a routine chore. Perhaps you need to go up to .60 pressure treated suitable for marine environments.