Compound Concrete Garage Floor

Hello all,

I've been looking into populating my 700 s.f. garage with some CNC machines and had some quick questions that I'm hoping someone here may have some insight on.

Long story short, the rear part of my garage (280 s.f.) was added by the previous owner. This rear portion sits on a compound concrete slab. The area below this portion of the garage acts as a basement for storage as well as an air compressor. A 10" wide concrete foundation was built around the perimeter.

The slab itself is 6" thick poured onto embossed metal decking. This is supported by (5X) 4.5" wide steel I-beams spaced roughly 37" apart on center.

Looking at getting a Miyano MTV-310 (super good deal / shape) and putting it in this area. The machine weight is approx 4500 pounds, has 4 leveling feet roughly 3' apart.

I was wondering whether or not this seems like a good idea putting the machine over this particular area? Sliding a floor jack across this portion, I can certainly feel some degree of "hollowness" which worries me in terms of the machine being on a sufficiently rigid surface.

Was thinking of spanning a couple steel load plates to distribute the weight across the I beams under it, but I don't believe that would address any rigidity issues, only load distribution.

Ideally I'd like to keep this machine and possible future equipment in the rear of my garage for accessibility sake.

Any thoughts ?

Thanks !

Talk to a structural engineer about the floor. The difficult part would be determining what, if any, reinforcement is present.

Why do people suppose that questions are more palatable if they are 'quick'? Why has no one ever asked lethargic questions?

When someone poses a quick question, all I hear is "I want a bunch of detailed information without giving any of the important details, and I want it to take priority over anything else that's already going on."

Once demo'd a building with concrete floors supporting machines,the floors turned out to be reinforced with chicken wire , concrete was "breeze"....coke dust in the mix....with a more solid topping.....Its amazing what will last for 50 years....with a bit of luck.

Put a couple of steel screw posts under where the machine will live.

Consider drilling a couple of 3/4" holes to thru the first slab and measure the hollow part. Also, consider pumping some kind of grout into that hollow area. That would make everything one piece, so to speak.

JH

In my first shop, I installed a 13k lb Mazak CNC over a basement that I formed and poured myself. The floor held up fine, but I didn't have enough power there to effectively use the machine.

I bet it would be fine. I would use some rubber or hardwood pads under the leveling feet though. Vibrations/resonance will likely be the problem with nothing but air under the slab.

I think you already know the answer...no it is not a "good" idea. Will it work if you do it? Maybe

I would check with a structural engineer. He may suggest a 4" thick reinforced slab.
The 280 sq. ft. x 6" slab with the I beams sounds substancial. An engineer can put your mind at rest with his
recommendation.
mike

Thanks for the insight guys.

I'll see if I can get a structural's opinion on the matter.

Definitely a good thought to place some jack posts for some additional support.

The plan is to anchor load plates with some hilti bolts and possibly put isolation pads under the leveling feet.

Next roadblock at hand: fitting an 82" high machine under a 72" garage door, as well as getting past a 79" high support beam between the front and back of the garage. Will probably require some demo / notching.

GregSY said:

Why do people suppose that questions are more palatable if they are 'quick'? Why has no one ever asked lethargic questions?

When someone poses a quick question, all I hear is "I want a bunch of detailed information without giving any of the important details, and I want it to take priority over anything else that's already going on."

Click to expand...

People are brought up in a fast food culture and quick check-out lanes. Can't blame the guy.

Around here garage floors are not 6" thick. Half that. Over-build and be happy.

We need to know the height of the steel beams as well to even begin to formulate a reasonable guess.

I_AM_MACHINE said:

We need to know the height of the steel beams as well to even begin to formulate a reasonable guess.

Click to expand...

(3X) W10X68 and (2X) W8X40

The layout looks something like:

Wall | W10 | W8 | W10 | W8 | W10 | Wall

About 37" from wall to center and center to center for the beams.

Area roughly 220" Width X 171" Length.

Bump.

Fit a Fanuc Robodrill T10C under my 75" header.

Probably had about an inch of clearance from the header to the top of the z axis motor bracket (motor removed for obvious reasons)

We will see how it holds up.