I will be building a workshop 40X40 and have a question:

1. How many inches of concrete is required for the floor if your plan consist of a Ben Pearson 9000SI Auto Lift?

2. Do you use steel wire to keep the floor from cracking?

3. Since building from the ground up, what heat and A/C would you recommend?

4. I have a Hausfelt 26 Gal compressor, but what would be a good Garage compressor that can run awhile without the constant motor running that I experience with this compressor?

Thanks

 

I dont know what the minimum requirement where you live is, so with out that the only thing that I can base this on is California standard. Minumum is 4" but I would go with a 6" slab if you plane on doing alot of "heavy" traffic on the slab. For the lift I dont know the model but I think it's a for post drive on lift ..... if thats the case you can put footers in where your going to put the lift and install the bolts before you pour your slab. The footers I would make 24"x24" that should be plenty good enough. That way all you have to do is install the lift after the footers and slab have cured. Sounds like a neet shop though, Good Luck!!

Mason

 

By the way if my calculations are correct you will need 30 yards of concrete for the pour.

 

there is a posting person in this forum that goes by the name ms-michelle she just built a garage that has me and a few others envious, to say the least. she has a web site with pictures and specs . you might want to check it out. my hausfelt 70 gal compressor has been everythig I needed and it was only 500 bucks. the advice I suggested to her about the lift was to use steel plate under the supports to spread the weight of the lift, ands rebar at at least 16" spacing should be good for cracking , bob

 

Just use the lite guage mesh to keep from cracking, and for anything under a dump truck, 3" thickness will work fine so long as you have a good gravel base. But like mason said, footers are the way to go with the lift. If you can, I'd pour the footers first and even install the lift first.

You should really look into radient floor heating. It's the best and cheapest on energy thee is.

 

I'd go with a deep base and footer under wher eyour post will sit and either 4' or 6" concrete on the rest of your floor.
Make sure and put plastic down on top of your rock and under your wire mesh, it will help avoid moisture draw from underneath. If you really want to do yourself a huge favor put polystirene foam board (1 1/2"-2") under your plastic and it will act as an insulation between your floor and shop. You may not think it helps much but it sure as heck helps when you're laying on it in the dead of winter, and it also helps to not rob heat from your shop.
For heat I'd go with a radiant floor heat, it would be the most out of the way and really that's where you want your heat anyway since you'll be closer to your floor than you will your ceiling areas. With radiant floor heat you could go with a geothermal unit or woddburner (or oil burner).
Those hanging reznor heaters are nice, but I'd rather have the radiant floor heat over an air-to-air type heater.
For a/c, if you went with a geothermal radiant floor heat unit you could go ahead and use your system to also cool your shop, you'd have to have an air handler set up but it could easily be done.

 

Off the concrete issue, consider framing in a Compresssor room that is insulated with batts or similar noise abatement material. Then, plumb lines down the walls of the shop for the hook-ups. It sounds like noise is one of your concerns. You might be able to get crafty and intake the air from outside and run the drain for condensation outside as well. It shouldn't take much more space than the compressor would use anyway.

 

A 40x40 foot, reasonably well built and insulated building in Atlanta, Georgia can be expected to need only about 9000 BTU per hour cooling and 20000 BTU per hour heating. This is at the 97.5 percentile design conditions of 22 (F) winter and 92 (F) summer. (The cooling load will be higher if you have a lot of windows or glass area).

The in-slab heating, while nice, might be overkill for your relatively mild winters. I'd suggest insulating at least the slab edge (if not the whole slab), and using a small air source heat pump for both heating and cooling. Size the heat pump for a little above the cooling load (say 1.5 tons or 18000 BTU per hour). Supplement the heat pump with a small gas or oil heater to warm up the place quickly, and to cover you for the coldest days when the heat pump runs out of capacity.

An alternative would be a gas water heater and in-slab radiant tubing for heating, and one or two "window shakers" (portable AC) for cooling.

The best strategy depends on whether you are going to be out there for several hours every day, or only using the shop 2 or 3 days a week for a few hours a day. Radiant floor heat does not warm up quickly, and isn't the best for intermittant occupancy.

 

DTL,
The last 3" slab I had poured for me was supposed to be 6 sack cement and it went completly to pieces in the first year just driving pickups onto it. The 4" slabs I have poured myself and will occasionally crack but nothing serious. My shop now is 30X60 on a mono slab 6" thick with 12" thick edges and not a crack one in 5 years. So the issue really comes down to how bad a day are you gonna have if your floor cracks. Concrete is a pretty cheap building material. Load your form first with a layer of 1" drain rock and pack it then lay down a layer of heavy contruction plastic 6 or 8 mil. Then the rock wont take any concrete in during the pour ( makes calculating easy) and the drain rock does not transmit heat easily and some what insulates your floor.
Mesh won't neccesarily prevent a crack. If you use rebar or mesh ( I would) it might crack but its not going anywhere. A slab that size you'll want to put cuts in anyway, then it will crack in the cut.
Remember there are about as many ways to do this as there are people with opinions. LOL

Ken

 

I have built several garages 20+ and on my personal garage this last timeI started with 24" foundation walls poured concrete not block then 6" of crushed gravel then 2 layers of 6 mil plastic then I bought hog panels from farm store overlaped them 6" then 6" slab 6sack mix then kept slab wet for 4-5 days with a sprinkler cures concrete slower to help elimenate cracking 4years later no cracks may seem like overkill but you want your shop to last the 24" foundation walls make hosing out shop easy hope this helps!!!! sprinkler is only needed if poured in hot weather I did mine in july

 

I luv thease post. I don't know about the guy who started the thread but I'm learning a lot. But please tell us what state you're in (makes a big difference what with the dept of the frost line etc.).

Titanic, is your 30x60 deep enough? How many stalls did you work into that size? Thanks.

 

Sorry I'm in tennessee my footings were 12" below grade and were 18" wide and 8" thick

 

As far as the compressor goes, I like to look for slow turning ones, say 500 to 700 rpm. Those 2000 rpm jobs will drive you batty, and the slow ones seem to last forever. I would think a 2 stage 5 hp is usually sufficient, but a good one, not a $400 discount club special. A 'real' 5 hp will draw 20+ amps on 220v.

 

mat,
My shop is 30 wide and 60 long. ( I think that is what you wanted to know) It's one big stall really. I have one roll up door in the front that is 14 wide and 12 high. The back 20' of the shop is covered by a loft that makes a good parts catchall and the space under the loft doubles as the best spray booth I've had yet. The front part is free span and has a 17' overhead clearance. The pad in front of the shop is as wide as the shop (30') and 25' long. 4"thick BTW. Being in southwest Montana we can park everything inside at night. I took my compressor and put it on a stand over the walk through door to get it out of the way.

Ken

 

I didn't realize this gy was in Atlanta, a full slab infloor heat system woudl be overkill for the milder winters down there. I would heat the perimeter very well and then put a heat pump in but I don't know exactly how mild winters are down there so I don't know if you'd want back up heat or not.