Southern Yellow Pine vs Dri-Core

[Glenn Samuels]

I have a new workshop (about 900 sq. ft) and it is on a concrete slab. I'd like to use some sort of a wood floor. I was speaking to a man who owns a mill locally and he can get me SYP for 50 cents a board foot. I was thinking of using 4/4 thickness. It would be air dried and in the 12% - 15% moisture range. I can also get it tongue and grooved for an additional $.25 for board foot. I realize that I would need to put a moisture barrier down first.

First question: Is a range of 12% -15% moisture too moist and will I see considerable shrinkage?

I am also considering Dri-Core which comes in 2' x 2' squares. It comes out to approximately $1.75 per SF.

I can use some opinions on the options below and any suggestions.

[Peter Kelly]

You might give this a read: http://www.sawmillcreek.org/showthread.php?128924-Delta-FL-Installation-Experience

Delta FL > OSB/Plywood > Top With T&G SYP. I wouldn't advise attaching SYP planks directly to the slab.

[Andrew Fleck]

I wouldn't put wood down on a concrete floor unless I built a subfloor on top of it using PT 2x. Some people will tell you that you can do it just using some sort of plastic as a moisture barrier, but in my experience that will eventually fail.

[Thomas Canfield]

Ditto what Andrew said. A moisture barrier against the concrete, and then PT 2x also allows being able to run conduit in the 2x space to get electrical out to the middle of the floor.

[Glenn Samuels]

On the PT 2x, what should the spacing be? Would you lay a moisture barrier down, then the PT 2x screwed to the concrete?

[Andrew Fleck]

On the PT 2x, what should the spacing be? Would you lay a moisture barrier down, then the PT 2x screwed to the concrete?



If it's your shop floor I would go 16" on center to better support the weight of your machinery and any unforeseen future machinery. I wouldn't screw at all, just get a Ramset or something similar to shoot nails down. That will be 10 times faster than screwing. You are basically building a subfloor with sleepers and 3/4" ply. Then put whatever wood floor you want on top of that. This will elevate your wood floor above your concrete allowing moisture to escape.

[Kevin Gagne]

I used the Dri-Core product in my workshop and think it is great. Makes the shop warmer and more comfortable. I haven't had any problems with machinery on the panels. I would definitely recommend them. Fairly easy and quick to install.

[peter Joseph]

I have a really small shop with very low ceilings (7ft) and posted here some years ago RE: how I might install an oak floor without losing to much headroom. I got a ton of great advice and ultimately went with OSB pl'd and nailed to the concrete and covered with a plastic vapor barrier. I had alot of concern as to whether or not the floor would hold up, however it was such as small space I was ok with the small investment required. Five years later, I have zero regrets. I'll be refinishing it soon as part of the regular maintenance but it has worked out wonderfully.

Just my anecdotal experience. If i had 3in more headroom however, id have installed sleepers.
Peter

[Jeff Duncan]

A couple quick thoughts….

If your building the floor up your going to want 3/4" ply or wafer between the solid and the sleepers. The pine by itself will have some flexibility to it, so you want to support it. Also if your thinking of heavy machinery, i.e., machines over 1000 lbs, it may be worth further research to see if closer spacing of the sleepers may be required? If the concrete is fully cured I think I'd skip the sleepers altogether though. You can lay down some flooring paper and use a power set to shoot the 3/4" material right to the concrete. I've done this before and it's fairly straightforward work. As long as the concrete is, and will stay dry, the sleepers add no benefit and only create more work and expense.

As far as the wood itself goes that seems a bit high on moisture content. I'm thinking you may want it a bit drier before installing. At the least I'd let it acclimate to the shop for several weeks before installing.

good luck,
Jeffd

[James Conrad]

As an alternative to what has been mentioned, lay down rigid XPS insulation, tape the seams and lay down Advantech T&G ply over. If you can swing it, get 7/8" or thicker Advantech. No need for sleepers. The XPS should have a minimum of a 25psi rating, you could prob get away with 1" in your climate and it acts as your vapor retarder. As long as you have a fairly flat floor you shouldn't have screw it down either.

[Jim Andrew]

I did a floor with 2x and t&g flooring on 19 3/16 centers, takes 5 boards per 8', and is less than 16" between sleepers. If you have your shop layout done, you can put some extra pieces of lumber under your machines to make it solid. Don't nail your sleepers down, once they are covered, they will not warp, and the next owner of your shop will probably want a concrete floor.

[Dennis Nagle]

If you are thinking about doing this to fight fatique, you might want to look at locking rubber mat.

[george newbury]

If you are thinking about doing this to fight fatique, you might want to look at locking rubber mat.
How well does the locking mat work with sawdust and dirt being ground into the joints when you walk around?

I make a lot of sawdust.

[Joe Cowan]

I did my shop about two years ago and used the advice from one poster that had researched how gym floors were installed. I bought kiln dried pressure treated pine and cut them all 3' or less. After putting down the plastic, I put a row of these sleepers without any screws, then the 2" rigid insulation, another row of sleepers (again without any fasterners) and so on. I put the Advantech, and a red oak T&G floor. All is great after these two years.

[Dennis Nagle]

It works really well. They lock tight and if dust gets in the cracks, it just tightens them up more. Before I did that, I use to leave sawdust on the floor to stand on and my doc said that is the best thing to do. Standing on a completely even hard surface for hours is very hard on your feet. Standing on a soft irregular surface (sawdust) will keep the bones in your feet from having the same pressure points all day.....that is what makes them hurt. Better than soft mats....that is why I took them out.


How well does the locking mat work with sawdust and dirt being ground into the joints when you walk around?

I make a lot of sawdust.

[Don Jarvie]

How level is the concrete? Most garage floors are pitched to the center or front in case of gas spilling. Most likely you will need the 2x4s flat to level the floor.

Best way is to start from the highest part of the floor and screw the 2x4s into the sill plate. I would not drill or ramset into the concrete floor should you resell the house over time. It's easier to unscrew everything and take it with you.

[Matt Neil]

James, just wondering what you do to keep the T&G Advantech together if they aren't fastened to sleepers. I want to put 4x8 T&G ply over a 15 psi or 25 psi XPS on 24" or 48" OC but figured I needed some sleepers to fasten the ply to. Then I'll put hardwood over the ply.

[James Conrad]

Hi Matt, I've installed it several ways - floated with no fasteners, tacked on the outer edges to sill plates, and Tapconed edges and field. Advantech goes together pretty snug, so it depends on your shop floor and environment if there will be any movement. Unless you are in a very humid environment it will stay flat, Advantech is a very stable product . If you have concerns about it moving, use Tapcons or tack the perimeter and spot Tapcon any trouble areas. You will probably have to tack the back edge on the first row during installation to keep your striaght line unless the wall you start on is straight. I just did my shop floor in October and floated it.

Edit: If you are going to put flooring over the Advantech, you will want to secure your subfloor down.

[Matt Neil]

I'm not planning on using Advantech, but instead 3/4" 4x8 T&G ply. In that case, would you lay sleepers 24" OC or 48" OC with a 15psi or 25psi EPS in between the sleepers? Or do you think 16" OC is needed with the XPS?

[James Conrad]

I'm not planning on using Advantech, but instead 3/4" 4x8 T&G ply. In that case, would you lay sleepers 24" OC or 48" OC with a 15psi or 25psi EPS in between the sleepers? Or do you think 16" OC is needed with the XPS?

What kind of flooring?

[Matt Neil]

3/4" hardwood. Not decided yet but leaning towards hickory or oak.

[James Conrad]

Well, since you are putting actual flooring in play it safe - sleepers secured down glued and screwed 19.2 O.C. , 1.5" XPS between, glue a screw the ply down.

[Matt Neil]

Is it ok if the seams of the T&G ply don't land on the sleepers since they are 19.5" OC?

[James Conrad]

Is it ok if the seams of the T&G ply don't land on the sleepers since they are 19.5" OC?

19.2 not .5

[Larry Edgerton]

I'm not planning on using Advantech, but instead 3/4" 4x8 T&G ply. In that case, would you lay sleepers 24" OC or 48" OC with a 15psi or 25psi EPS in between the sleepers? Or do you think 16" OC is needed with the XPS?

In my opinion, being as money is about the same Advantech or equal is a better option than plywood. I use it {Grace Brand} on every house I build. On my own house it was under water for three weeks as it rained every day that I framed it, and it did not swell one bit. It hold fasteners every bit as well as plywood if not better. I no longer use regular osb because of the swelling, and plywood delaminates when it is wet, which in my climate will happen before the roof is on.

It is also what I will be using in my new shop, painted, with ductwork and electrical underneath.

Larry

[Jim Andrew]

If you look at your tape measure, it has a mark similar to the ones at 16, 32, 48, etc on 19&2. Takes 5 per 8' instead of 6 per 8' and comes out 8' on center.