# Cover a concrete garage floor with plywood?



## Smile_n_Nod (Jan 20, 2011)

I'd like to cover the bare concrete floor of my workshop (located in my garage) with plywood. Can I just lay several sheets of plywood edge-to-edge on the floor, or do I need a vapor barrier underneath? Should I use pressure-treated 2×4s underneath the plywood? Any suggestions? Thanks.


----------



## chrisstef (Mar 3, 2010)

yes you will need a vapor barrier, concrete will hold moisture and slowly seep it back out again. Id go with the PT stringers underneath with a vapor barrier under those as well. The cavity may allow you to run your dust tubing and electrical underneath as well.


----------



## Loren (May 30, 2008)

I'd elevate it. The concrete can hold and move moisture which will get
into plywood sitting on top of it. You might want to paint the concrete
with a mold-resistant paint first.

If you can handle the loss of headroom and the step up it can be cool
to run dust collection pipe and electric underneath the floor.


----------



## rustfever (May 3, 2009)

First, a vapor barrier, lapped and sealed
Second, sleepers, pressure treated shot down to the floor
Third. prime the underside of the ply [ edges and t&G also] to further prevent moisture
Finally, ply, preferable T&G, screwed down
All seam must be loose to allow for seasonal movement
Hold back from walls about 1/2" to allow movement
Cover the 1/2" at wall with a full 3/4" thick 'Baseboard'
Treat the floor surface to prevent dirt, stains, & moisture from entering


----------



## SCR0LL3R (May 28, 2010)

I always thought that most primer doesn't protect against moisture?


----------



## newbiewoodworker (Aug 29, 2010)

Im not sure what your height requirements are, but I agree with Chris, if you can afford the height, then you may want to put in runners of maybe 4.5"(2×6 ripped) and then the TnG ply… That way you can run stretches of electrical conduit(floor electrical direct to tools) DC stretches, possibly plumbing, etc. I think if you can afford it, height wise and finanically, then you will be kicking yourself if you dont do it.

Definately put a Vapour barrier down first.


----------

