Help turning raised deck into woodstore

[BoltonSte]

So, I have a multifuel stove and I have a raised deck in the garden (about 3' off the floor). I did a botch job using ply that was the cellar ceiling when we moved in to keep the worst of the weather off the wood I stored underneath it, but want to make a proper job of it this year.

The deck is on joists and legs, and I'm trying to figure out the best way of waterproofing underneath it, I've looked at off the shelf answers like corolux corrugated PVC to place between the joists, but the widths and lengths I need don't match up, I've also looked at using exterior/marine ply, in the same way, but because of the lengths involved (up to 3m) off the shelf stuff would need to be overlapped.

My current thought is to take all the decking boards up, board the whole thing with exterior ply using those plastic edging strip things (no idea what they are called) and silicon to join sheets (they will be well supported) and stop water dripping through. Then have some spacers (probably from the ply) to go where the boards fasten to the joist so there is still space for the water to run off.

Does this sound reasonable, does anyone have any other ideas?

This
____
[] []

to

____
__ __
_____
[] []

(Best I could do at the moment)

Ste

[Specialone]

Exterior ply won't last, it might be water resistant but wont stand up to persistent wet environments.

Id be more inclined to use a black heavy weight DPM, stapled or something to underside of the joists.
But, you will need to make allowances for some water run off or it will just fill up with water.

[BoltonSte]

I was wondering about DPM but didn't know if it would hold on staples...I'll see what I can figure with this...easy to cut to size as well.

Cheers

Ste

[keith_d]

Rather than stapling DPM to the joists attach it using wooden battens and galvanised nails. Install with a 1/24 slope so that water runs down to a suitable spot for drainage.

For longer spans fix another batten to the underside of the deck boards in the middle of the span, parallel to the joists.

[BoltonSte]

Been looking into this, all I can find online is 1200 gauge. Is this what you mean by heavy duty or is there somewhere else I should be looking that's more specialised?

[Specialone]

Screwfix.com have loads...
http://m.screwfix.com/c/building-joinery/membranes-barriers/cat850236?cat=cat850236&nbcol=1%7Cunknown&_bck=1

[BoltonSte]

I just wasn't sure if 1200 was one mans heavy duty, another mans tissue paper. But looks reet I'll get some sorted.

I am currently a mouse free zone. I had a couple last year so put traps and posion down. I was getting one a day for a week and the poison kept going after that. Even got a rat in the gin trap (I'd seen it walking over the deck). I run sample traps now and again to keep an eye in things. I blame the takeaways across the road, the fields behind, the restaurant at the end of our terrace and the raised bed I had which I found the base wase filled with rocks.
Cheers folks

[timwilky]

If you do want heavy duty then http://www.cwberry.com/Inquiry_ProductDetails.aspx?ItemNumber=02190195