New workshop planning ideas....

[Eddie Kee]

I am going to build a workshop this spring and move out of the basement. I am planning a 30 x 40 building with 9 foot ceilings. My big concern is the floor. I would like a wood floor and not concrete. I was thinking at first of having an insulated slab pured and then placing placing wood 2x anchored to the concrete and then plywood and oak on top. I have 1000's bf of airdried oak that I will use for the final floor. Then the though accoured to me to just pour colums and build a joist floor system out of treated lumber. Filling between the joists with gravel, placing a vapor barrier down and then plywood with the oak finish on tope. Any thoughts. I want to make sure the critters have a hard time getting in since we live out in the sticks and that is the reason for the gravel between the joists. The building will be heated. Any thoughts or questions would be approciated.

Eddie

[Tim Douglass]

I'd go with your wood over slab approach, but either would really work ok. I think you climate will determine which is best to some extent, since wood near the ground in wet climates isn't too great an idea, but with the slab under it would be fine.

Also, I'd bump that ceiling up to 10', occasionally I even wish I had gone 12' instead of 10.

-- "We need to make a sacrifice to the gods, find me a young virgin... oh, and bring something to kill"

Tim Douglass

[D. J. MCBRIDE]

Do the oak over screeds tarred to the slab just like interior hardwoods are traditionally done.

[Derrick]

Depending on the seriousness of a potential critter problem. Suggest you pour slab, vapour barrier, then the plywood, then you might consider a layer of foam (for floating floors) then your oak top. Critters have been know to eventually eat through wood, cement will stop that problem. I added the comment about foam because it will help even out stress on the top layer with weather changes and help insulate. Sounds like a great size shop. I'm jealous as mine is 9 X 30. Good luck with the build.

[Mike M]

[Robert Bonomi]

First things first. Even if you don't have "building code" requirements to satisfy, you don't want to put untreated wood "close" to the ground. How close is 'close' does vary by climate/locale -- you'll need to consult local expertise. That said, something in the range of a couple of feet is common, in _non-termite_ territory.

If you don't want to go slab-on-ground, consider a real raised floor, _over_ _a_crawl-space_. *Much* easier to inspect, and to do repairs on, *IF* needed.

Note: you _really_ want the ceiling higher than 9'. Measure the diagonal of a 4'x8' sheet-good, and you'll understand why. *Especially* if you have occasion to deal with any of the 'oversize' 49"x97" stuff.

9'6" is a good minimum, more if you'll have surface-mount lighting.

[Ray]

The gravel will absorb moisture and speed the rot of the treated lumber. In the NE we can't buy 'real' treated lumber anymore.

I agree with Robert, raise it a little. This will allow air to flow through and keep the moisture down.

If you do decide to put sleepers on a concrete pad, consider radiant floor heat if you are in a cold climate.

[lm1angel]

hello i'm larry, using my wife's email

A slab foundation is great if you make sure to build it high enough to have MINimum of 3 inches viewable foundation above the soil, 6 inches is ideal.(this means your siding or other material never touches the ground) dont build flat!. Build up your Pad area, bring in clay and get above the water table. and make sure all your footings go below ground. water is most damaging when it washes under a slab. a slab is almost the most expensive part of a building. if you put wood flooring on your slab, either glue it tight and seal it down, or run it on cleats, to let moisture dry from under the floor. a slab will draw moisture through it, concret is porous.

IF you go with a pier and beam you need to stay 14 inches above ground level with any wood material."i.e. the bottom of the beams" you need to be able to crawl under it yourself, or any other repairman. For critters just run screen mesh, or wire. you have to let the air flow under to let the soil and wood dry out, so dont pack, stack, or clog up the under side of your building. moisture causes rot, and bugs.

I'm a professionl termite exterminator. so i know about rot moisture and termites. keep it dry and clear of the ground

of course i'm talking worst case, and best suggestion. I belive if you plan on the worst happening, you may only have minor dificulties, not problems.

[Grant P. Beagles]

If you plan to sell the place someday and the shop could become a garage then a slab would be the ticket. The second method you mentioned is called pier and beam. Most older homes around here (Dallas-Ft. Worth Metromess) are pier and beam. If were building a stand alone shop for wood working only, I would think seriously about using pier and beam. I have been under a friends house that was built in the early 50s without treated lumber and everything is just fine. His house has a concrete wall around the perimeter to keep critters out. There is no vapor barrier so some ventilation is critical. The plus side is that all his plumbing, HVAC ducting and electrical is easily (relatively speaking!) by crawling under the house.

Grant

Eddie Kee wrote:

[Roger]

I'd think in terms of a crawlspace, if not a full basement. It would allow you to easily run power and dust collection under the floor, eliminating the hassle of getting services to machines out in the middle of the floor. With even a partial basement you could put the DC and compressor down there and get the noise out of your workspace.

Roger

Grant P. Beagles wrote:

[Bob G.]

==================================== Since I am in my 60's and as of now anyway have no intentions of moving I guess I will not be building another shop ...

BUT If I were building one...

It would definately have 10 foot ceilings. If it was anyway possible it would have a full basement under it... At least one door would be the size of a standard garage door.. I would have 4 times the electricical outlets that I thought I needed It would be heated (furnace in the basement) It would be air conditioned no smaller then 24x36 .... Bob Griffiths.....