Flooring over a deck

belizeanbus

I am refinishing an addition on my house that was made by the previous owners. Essentially, it is the deck off the back porch, which has been walled in to be a sort of mudroom. As such, it is not built on the house's foundation. From underneath, it is simply a deck, with 2x6 decking. So far, I have laid 3/4 in plywood on top of that. I would eventually like to finish the floor in bamboo as part of a conversion to a studio for my wife.

Question #1: What do I have to put on top of the ply before laying the bamboo, in order to avoid moisture problems?

Question #2: I want to have the floor insulated. The previous job, which needs to be redone, essentially involved fiberglass insulation installed from below, and then thin ply attached under the deck to create kind of a box for a floor with insulation sandwiched in between the plywood and the decking. Is this my best option?

Any advice would surely help!

~belizeanbus

just tile

how water tight is this room? i would insulate and then use a heavy plastic sheeting atleast 4 mill then plywood for the underside. you should have put down some felt before the 3\4 in ply wood.good luck.

sdsester

Your building department and inspector are alright with this? You are essentially turning a infrequent use deck foundation into one for a permanent room addition? Sure you want to put all that floor and wall weight on the existing deck only foundation even if you can get away with it under cover of darkness? This addition is not also supporting its own roof is it?

This is one of the reasons building codes had to be implemented by the way. This project sounds kind of third worldish and frankly dangerous to me.