# Plywood Flooring



## DeansDust (Sep 8, 2012)

Well, here I go. I'm gonna put a 3/4" floating plywood floor down on my concrete flloor. Not gonna use any sleepers, and not gonna use tongue and groove either…just good ol' 3/4" AC grade plywood.

I did a vapor test in my shop by duct taping a 14" x 14" square of heavy mil visqueen and observed for the last 10-12 months that no moisture or condensation formed under the visqueen.

Alas- no moisture or condensation formed. Far out!!!

So now I am gonna lay down a nice heavy felt paper over my 30'x40' concrete shop floor to float my plywood on. The slope inherent to most shop floors is negligable…so I won't sweat that part.

I am gonna use unglued biscuits and with good clean square panel cuts to keep my floor flat and fit- and to allow moving and shrinkage.

Now then, could a fellow jock tell me what I'm over looking? Please talk me out of anything that seems stupid with my floor project!

Thanks for any interest

Deaner


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## LeeBarker (Aug 6, 2010)

Good prep, Deaner.

How small are you going to cut the ply? If there is any bowing in the sheets, the smaller the better I would suppose.

There will be no shrinkage with the ply indoors.

I'm envisioning the biscuits being stapled in from the top. It wouldn't be a super joint, but it would keep it all together as you assemble.

If you alternate grain direction it would look pretty cool….until you start putting machines and benches and cabinets on it!

In summary, I'd say go for it, and again kudos for your prep and thought.

Kindly,

Lee


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## Newton (Jun 29, 2008)

As Lee said keep the sheets size to 4×4 or 2×4 as recommended by the NWFMA. I would at least seal the underside of the plywood and the edges. Stagger your joints when laying the plywood and allow a minimum of 1/8" gap between panel edges. There is an "Underlayment Grade" plywood that is not T & G. The underlayment grade doesn't have any voids in the core.


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## DeansDust (Sep 8, 2012)

Thanks Lee,

Good idea on the staples. That's all it would take….if anything at all is used.

I think you are right about a couple things:

I'd prefer to use full sheets for fewer seems, with 2×8 sheets around the perimeter against the walls. By not gluing anything, I could still pull up indivdual panels in the event of damage, wear or need for access.

The idea of using smaller panels alternating direction , i.e. 2×2 pieces, is saavy and would be just as you said: cool
I calculated that I need 20 sheets of plywood…and that translates into many fewer cuts…and that in turn would translate into 80 cuts if I used 2×2…and only 40 if I use 4×4 panels. Either size would be great, no?

So OK: you talked me into smaller squares with alternating grains Lee!

Cool indeed- thanks! I'll be posting pics of the project pretty soon, as I find it interesting how little info is actually posted out there.

taker' easy- more soon!


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## DeansDust (Sep 8, 2012)

Good suggestions Don. I'm gonna look for the "underlayment grade" plywood. Lordy, it couldn't be any more expensive in my neck of the woods (WA) than the 23/32" AC ply I'm using from Home Depot…could it? LOL.

Clarification please: 1/8" gap between every panel edge…or…1/8" gap just between outside panels and the wall? Wouldn't a bunch of 1/8" gaps at 2'x2' apart seem…I dunno…odd?

I appreciate your interest Don.


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## Earlextech (Jan 13, 2011)

I would glue the biscuits and panel edges together but leave 1/2" away from the outside walls for movement. Otherwise you will have movement in different directions and gaps where you are working/walking.


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## DeansDust (Sep 8, 2012)

Good call Sam- I see what you're saying. Especially when sliding stuff arond on the plywood floor.

HONEY- grab some Gorilla glue when you hit Home Depot! Oh- and don't worry about the 20 sheets of plywood, I'll get the kids for that


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## ClintSearl (Dec 8, 2011)

Consider 3/4" T&G Advantech decking. IMO, it's superior to ply, and costs less.


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## DeansDust (Sep 8, 2012)

Indeed I will consider that Clint. I'll look for it. Thank you


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## DeansDust (Sep 8, 2012)

Well Jocks,
Took a lot of your ideas and mingled them with my own, and here are a few pics of my start.

I began with 10 sheets, cut them into eighths, table sawed each side on each eighth for squareness and size; the set up a production jig to biscuit each side with 3 biscuits…anybody doing the math??? LOL

I then arranged them in a checkerboard fashion, again, 3 biscuits per side and gorilla glued the only the corners.
Anyway, this yielded 80 23-3/4" sheets which covered 27'x12'--or 1/3 of my total 1,200 sq. ft shop.

I'm BEAT!

Now I got to apply a finish to this section of floor so I can move things back into place to begin the next 1/3rd section.
The moving of all the shop stuff is killer too btw! Got any ideas on the finish? I'm leaning towards either satin polyurethane, or linseed oil- any thing else worth considerin' you 'spose?
Hope you'all are building some cool stuff out there!


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## Swyftfeet (Jun 15, 2012)

I think it looks great!


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## DeansDust (Sep 8, 2012)

Thanks Brian- the proof will be in the puddin'.
Am pretty scared to be thinking of rolling anything over it! lol. heck- the only thing on it so far are my socks!


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## Swyftfeet (Jun 15, 2012)

I would use oil based poly, but thats just me. I did a ton of reading on a hardwood flooring site about 3 years ago and Bona Traffic was considered the way to go for water based.


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## Manitario (Jul 4, 2010)

I used spar urethane on my shop floor, it's durable, easy to sweep and easy to wipe up spills and stains.


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## teejk (Jan 19, 2011)

pretty expensive solution for a shop floor! but since you started, oil base anything if you can open the doors and let it dry dust-free. or maybe one of the garage floor epoxy coatings.

personally I would have cleaned the concrete and applied the epoxy coating…a mess and it stinks but it works.


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## Finn (May 26, 2010)

I recently moved my entire shop including the floor. I had 3/4" tongue and groove ply floor screwed down onto floating 2×3's. In my new shop I just put the same ply, plus some needed in this slightly larger shop. This time I just layed it down on the concrete floor that had a glued down felt rug cushion. IT went in quickly and I like it. I put no finish on this floor at all.


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## DIYaholic (Jan 28, 2011)

Looks great!
I'm about to do something very similar. My very uneven concrete basement floor will receive a covering of 2' x 2' "DriCore" sub flooring T&G panels. There is a "nubby" plastic vapor barrier supporting the OSB floor. As OSB is ugly, I'll be painting it with grey floor paint.

Keep us informed of your progress and the floors performance.


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## DeansDust (Sep 8, 2012)

So Mr. Finn, did you put your sheets down in 4×8 panels or did you go with different dimensions? Also, did you glue your panels?

DIYaholic, I like your idea- OSB with a paint finish. So I understand, you have the 2×2 subflooring, with OSB flooring?

I haven't calculated how expensive my project is to date…but I will be keeping an eye peeled for other affordable methods. Hope the price spread ain't toooo great!

Anyway- I am liking it so far. While it is flat and snug, there is slight bounce between the 2×2 panels…even as they sit quite flat on the asphalt paper on the concrete. I am thinking they will settle into a snug fit as it acclimates. I will keep everyone posted, and look forward to hearing of your floor experiences.
I am fascinated by the number of folks on this site, as well as other sites that choose not put a stain or sealer on thier plywood floors.
OK jocks- thanks for weighing in- more soon!


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## OggieOglethorpe (Aug 15, 2012)

A local Tex-Mex restaurant used 4×8 sheets finished with floor polyurethane in their bar area. After 15 years, or so, it's held up pretty well.

I don't know how often they refinish it. They randomly branded the surface before initial finishing, and thr brands still look good, so I know they haven't sanded it.


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## DIYaholic (Jan 28, 2011)

DRIcore subfloor is used in damp/wet basement settings. This is the only good image I could find.









It is T&G with an adhesive already in place on the T&G. The black "nubby" plastic side goes face down with the OSB side facing up. The panels are 2' x 2' x (about) 3/4", costs $5.97 each @ HomeDepot. I got 50 free from a relative and 35 for $100 off of CL, enough to do my 13' x 20' basement shop (and then some).


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