I am building an uncovered deck over a concrete block room with a slab floor in a southeastern, coastal, hot and rainy environment. I want the deck to be made of pressure-treated tongue and grove boards. I am concerned that water will make its way into the room below. How can I make the deck waterproof? Should I use a plywood subfloor with membrane?
I would also like to know how much pitch the deck should have over a 12 foot length. Any and all suggestions would be appreciated.
Thanks.
Replies
If you scroll down to the bottom of this page they have a few of those under-deck waterproofing systems you could check out. I've never used any of them though.
I'd use a membrane myself, but then you have T&G sitting on a membrane which isn't good, no air flow under the decking.
http://www.deckmagazine.com/resources.html
check out http://www.duradek.com It's not a diy, needs to be installed by a dealer but it works well.