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 (
http://www.lockdry.com/contact.htm ) 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.