I have wood rot on the outside of my doors towards the bottom. I have one of those composite decks and it holds water a little too well. Who would you call to repair this? I just have no idea where to start.
Call a carpenter or handyman who can replace the rotted wood and fix the deck. Decks should not hold water, and especially against the house.
Your best bet would be to use something like DryZone or DampStop. They're the most effective methods according to pros who buy from our store :)
Other than that, try using a tanking slurry.
Here is a link that might be useful: Tanking Slurry
Are you saying that the wood alternative deck boards are holding water? I was thinking of using them to replace the few boards that are rotting on my lower deck. I have a web site for you to check out that was my bible when I redid my upstairs deck of my MB it is called bestdecksite.com it really was terrific when we redid our deck. Forget the HD how too books... The reason I referred you to that side is that if you support beams are getting weathered from the water that is seeping thru in between the boards this site had a great solution which was to cover the support boards with roofing felt so that the water can't get to them I thought it was a terrific Idea and will implement it when the lower deck eventually has to be totally redone. But for now I just want to do a few boards and am now concerned by your findings.