waterproofing under deck

[xlogger]

I've been thinking about adding on to my deck and pouring a slab under it for a carport. We want the deck boards like the others 5/4 treated but need something under to run water away. My real plan is to move my planer out there for more room. I know it will be somewhat harder on the planer but I will get some thick insulated blanket over it (the sides will be open). Anyone have any ideas what to do under the deck boards that will move the rain water out the end?

[69bronco]

Taper the joist bottoms with progressive shims and screw roofing tin to them from the bottom up. Just screw in the ridges, they market some kind of panel for this. Can't remember what it's called, same principal kinda.

[Chuck White]

Why not just build a roof up under the deck, and the pitch of the roof will divert the water which ever direction you wish!   ;)

You will end up with a dry work area, with the exception of what might blow in!

[Bruno of NH]

I've done it like 69 bronco many times with great results.
Have a pellet shed at my place under a open deck done like that
Bruno

[21incher]

If you haven't built the deck yet couldn't you have aluminum pans bent up to drop over the joists before putting the decking on. Be a little tricky to bend them so they taper out, but they would not need that much pitch and would be hidden in the joists so nothing hangs down. Could just have them bent from coil stock:)

[Delawhere Jack]

Lowes carries PVC corrugated panels made just for that purpose. They also carry an economy grade galvanized panel. If you go galvanized, be advised that the edges are razor sharp........  >:(

[DelawhereJoe]

I'll second Chuck W. it would be nothing to sister up a 2x next to the joist and get whatever pitch you want from an under roof. Doing it this way you wouldn't have to worry about shims splitting. The only thing you may have to worry about is the water that melts off your deck could freeze to your roof panels and rip them off once enough weight builds up. Unless you live somewhere warm then disregard the whole freezing thing.

[xlogger]

We don't have lots of problems with snow here but more with freezing rain and ice. You are right that could be a problem.

[Bruno of NH]

I live in NH and we get lots of ice and snow
Never been an problem with ice and snow build up always melts out quick

[Bruno of NH]

Start at the house side with a 3/4 furring strip and every 2'oc add 3/4 inch to the thickness of the furring strip untill your at the end of deck then screw roofing on
I used pt furring strips ripped on the table saw screwed to deck framing

[newoodguy78]

I've done what Bruno is describing several times on different jobs. Every time it worked out well and the customer was happy

[Crusarius]

Be careful with any type of metal. the cut edges will rust. May take a while but they will.

[xlogger]

The problem we have here in my part of the south is more rain then freezing, that takes down trees. I didn't think about that till Joe said it. If it snow and melted we would be fine with doing that. I would think I'd be good maybe for years and then we get that and it would be a great weight on panels under the deck.

[Bruno of NH]

The water runs out of the channels at the end of the deck
Freezing rain happens here often

[crowhill]

Just North of Bruno at Centurra Park across Rt. 120 from Dartmouth Hitchcock Med Cntr  a building was built this fall with, I think a new type of decking that channels the rain away without going thru was used. From what I understand the decking just interlocks creating a channel. I bet it has a hefty price being it is made of some type of plastic or vinyl preformed!