# Deck construction - spacer under sleepers



## Quercus (Jun 19, 2012)

I’m fixing to put a deck on an old (but solid) concrete slab. "Sleepers" will be 2x6 on edge (because I'm extending 18" past the slab). I want to put some non-compressable, non-rotting item under the sleepers and shims to keep the wood up off the slab and out of any water. I've seen plastic Handi-Shims, which could work as they are constant thickness, but it seems there must be some cheap material, probably made for some other purpose, that I could cut into 3" lengths and put under the sleepers every 2' or so.
I thought about cutting up the aluminum channel from old storm windows, but it is not solid enough. Could I use 1/2" rebar? the last owner left me piles of it, but I would prefer not-round and not-iron. Someone suggested vinyl lath, but that is a bit thin, and is it sufficiently compression-resistant?
I HOPE YOU HAVE A GREAT IDEA - THANKS FOR ANY HELP!


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## Millertyme (Apr 20, 2010)

I'm not completely sure but I think what you should do is lay down a vapor barrier then you lay ridged foam insulation, then your sleepers. Maybe someone else can chime in


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## joecaption (Nov 30, 2011)

What your trying to do it not a great idea.
Vinyl lattis is enough to keep the wood from making direct contact, and will not compress.


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## Millertyme (Apr 20, 2010)

I guess I mis read the op. I thought you were in a basement.is the slab level


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## Quercus (Jun 19, 2012)

Not perfectly level (what is?) but only about 2" off over a 12'x14' area. It will take some serious shimming, but my main concern is spacing the framing up off the deck a bit to keep all wood away from water. 
Other commentor is endorsing vinyl lath, and that may be the way to go.


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## CopperClad (Jun 22, 2012)

Sleepers.. 2x6 on edge? so your standing a 2x6 upright to carry your floor joist? or the 2x6 on edge is your floor joist?


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## Quercus (Jun 19, 2012)

2x6s ARE the joists, with decking right on top. Maybe 'sleeper' isn't quite the term, as that implies wide-side-down orientation to many, but they go right on the slab, EXCEPT for some kind of spacer, and just what that spacer is, is my main question. thanks


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## joecaption (Nov 30, 2011)

I'd be more inclined to rip the joist to the taper needed so there would be 100% contact with the slab to eliminate any floor bounce or sagging in the future.


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## AtlanticWBConst. (May 12, 2006)

Use Pressure Treated Lumber over a vapor barrier.

If there were any worries about PT being drastically compressed (while being used between concrete and weight baring structures), it wouldn't be used for mudsills on new construction homes & buildings, decks and other structures.

(In the Pictures; The thickness/height of the PT sleepers were dictated by the composite deck board brand manufacture's warranty stipulation - for minimum air flow space)

Example:


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## Quercus (Jun 19, 2012)

Thanks for all the input everyone! And nice lookin' porch AtlanticWB

My revised plan is to put down a vapor barrier on the slab, 6 or 8 ml polypropylene.

QUESTION: should the VB be adhered to the slab, or just held down by the structure above it? If adhered, just around the edge, or all over? Best adhesive?

I hear what joecaption is saying about 100% contact of joist to slab, but my surface is variable enough that I’ll shim up to high point rather than scribe down to low point.
And I’ll use short lengths of vinyl lath between VB and joist every couple of feet to keep the wood away from water– a 2x6 shouldn’t give bounce at that short span.


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