I’m estimating for a pole-construction woodshop (my own). It’s 32X32 salt box style. I’m debating between framing a floor deck on the posts/piers, or pouring a slab instead.
For the slab, I would wrap the bottom of the perimeter posts with a PT rim joist, and that would be my form. I’d probably put a layer of 2″ poy-iso insulation board between this rim and the concrete slab; as well as 2″ foam board under the slab.
?’s:
1) Am I asking for trouble with a floating slab in a woodshop? (ie movement with seasons, I’m in upstate NY). Besides a thermal break, I though the 2″ poly-iso board between slab and framing would give it some wiggle room as it moves up and down.
2) any rules of thumb on 2′ costs for each option? I’m wondering, by the time I frame up all the joists, and put a 3/4″ ply deck down, and insulate bewteen joists…would the gravel/foam board/slab/rebar be about the same cost (but maybe quicker)?
3) space will be heated (most of the time). If I wanted to bury pex in the slab for a glycol RFH, would the potential for movement in this floating slab negate rfh as an option? even if the HWH was located on top of the slab (ie moving at the same rate as slab)?
An added benefit of contrete would be the ability to pull a vehicle in there to work on. Not great to do on a wood deck.
sorry for the long message, any thoughts/ideas appreciated!
Replies
Slab. I don't see it as a cost issue. Put in a drain or two so you can hose it out. A friend of mine put put heating in his, and he uses it as a mechanical workshop. It's heaven to be on a creeper in there under a vehicle in the winter. Good luck with the project.
I had a Morton pole barn built a couple of years ago (first class building, by the way- I build another in a heartbeat) and went with a slab- 4" concrete, with fibre reinforcement- 1/2" black board at the edges, and 2" Styrofoam board insulation 2' wide all around the perimeter. Over 6 mil polyethylene and compacted gravel, of course. The slab is 24' x 32', with shinkage control breaks each way. I finished it with epoxy conc. paint, and couldn't be happier with the way it turned out- easy to keep clean, nice to work on, and easy to heat the building in winter (though, I must admit that here in Maryland, winter isn't the same as upstate NY)
Homebody,
Does that mean that you think the costs would be equal, or just that the slab would be superior?
I'm certainly concerned about cost....esp if it means I get a woodshop this year vs next year ;)
Sould I be concerned about the slab movement, or am I worrying for nuthin' ?
Sorry, I've been out of the loop for a few days, Stray - busy! I was referring to performance. Of course, you could build the building and put the floor in later if you needed to phase the project. Good luck!
Sorry to butt in on Stray's thread, but JKM's post caught my eye.
I live in Maryland also and am about to build a 25'x40' workshop. I'm debating whether to stick-build it myself or have a pole building installed by Morton.
If I'm not being too personal, would you mind saying about what Morton charged for your building?
Also, my parents had a Morton pole barn built 25 years ago. Their barn is uninsulated in the roof and walls. Is your shop insulated? If so, did you do that yourself or have Morton do it?
Stray,
I'm have to make the same decision as you. I'm leaning towards a slab. I want to heat it with RFH, and embedding the PEX in concrete seems more efficient than staple-up installation under a wooden floor. I will, at times, have very heavy items in the shop and don't want to worry about the floor. I'm also a little uneasy about concrete piers that could move independently. (Frost heave can move piers even if they extend to below the frost line.) Finally, the durability and fire-safe nature of the slab is a plus.
A wood floor would have its advantages too. I think the wood floor would be easier on my legs and back. (It's a woodworking shop, so I'll be on my feet in there for many hours at a time.) It'd also be easier to run electric and dust-collection under a wooden floor. And aesthetically, a wood floor is more appealling to a woodworker. (How much would 1000 sq ft of t&g white oak cost?:))
My rough (VERY rough) estimates are that the costs are pretty close. I WAG'd that materials for each floor would run between $1000-$1500. Labor (mine) would be higher for the wood.
That's not much information to go on, except that another guy in your shoes is leaning towards choosing a slab.
JJShaw- My morton building wasn't the cheapest, but considering that they did exactly what they said they would do, and caused me zero grief, I am very happy with the results. I built a 2x4 interior wall, flush with the inside of their poles, for insulation, wiring and air lines. 6" roll insulation, plastic vapor barrier and 1/2" drywall finished it off. Since I have 8'-6" inside height, I put a 6" base board so I could still get by with 8' drywall sheets. The ceiling required 2x4 runners at 2' O.C. to deal with the morton trusses, which are 7'-6" O.C. The building is easy to heat, and stays cool. Morton is located in Gettysburg, PA, and everyone you deal with is very professional, unlike some pole barn companys. Do it.