Water tight deck over a room

[Tom H]

I have a 10'x12' deck and want to enclose the lower area for a storage room. For this to work I need to have the deck surface water tight. I would replace the old deck board with new. The only decking I have found that's water tight is aluminum Lockdry (

) and it is very expensive.

I'm thinking of using composite decking and cutting a 1/2" spline pocket in the edge of each board. Then installing it using pure silicone in each pocket with a 1/4" x 1 1/4" spline between each board. Leaving 1/4" of the spline showing between each board.

I would use that galvanized angle iron with elongated holes along each joist to screw the boards down from underneath. Placing the screws w/washer in the middle of the elongated hole would allow the entire deck to expand and contract with the weather.

Any comments or ideas.

[Leon]

[Wood Butcher]

Here's a few more links. I was going to do the same as you but haven't managed to get around to it yet.

[Highland Pairos]

We use Dry Space when it is called for under our decks. When installed according to the manufacturers instructions it works great.

Steve P.