Slab on grade over XPS Foam. Should I be worried about a heavy forklift + my VMC?

I am getting ready to move a VMC into my "new" shop.
I am interested in hearing some input on how much load is too much for my concrete slab.

The details are as follows:

VMC: Kuraki KV-700 VMC (weight is estimated at 12200 lbs)
Forklift: Rental machine 20K - 22K capacity with pneumatic tires. (weight estimated at 22000 Front / 18000 Rear [unloaded])

Concrete: 4000 PSI mix with fiber poured 6" thick over 2"(R-10) Foamular XPS 250 foam. (just over 2 year old slab, so it's had time to cure).

Re-mesh is #9 x 6" and is about 1.5" - 2" up from the bottom of the slab covering the entire area.
Rebar is #4 bar (1/2") on a 18" x 30" grid where the machines will sit, but I have to drive across the middle of the shop that has #4 re-bar on a weaker 76" x 60" grid.

This is a monolithic slab with turned-down footings (no foam under footings). I reinforced the area in front of the 12 x 14 door with an extra 38" x 22" grid of #4 bar extending 40" into the field to prevent that transition across footing to field from breaking.

The reason for the XPS foam insulation is that this is a radiant heated slab with a grid of 1/2" pex on 12" centers.

I'm not asking for engineering (in spite of all the detail) just your experiences with how worried I should be about this.
Is driving a heavy forklift with a 12000 lbs load into my building something I should even be considering?

This is my first thread here, although I've been reading things on the board for years. Hopefully my post adheres to the rules.
Thanks in advance for any input you guys can give!

I can tell you that we had a 24000 lb shear into position with applicable forklift. No damage to a 4" slab. The foam is probably less locally compressable than compacted sand...just talkin out of my ass though...we may have gotten really really lucky.

I have a 4" slab over 2" eps foam and two 8000 lb machines, no room for a forklift. Slab is fine but trying to keep the machines level is futile. If I had it to do over again I would have skipped the foam and gone with more concrete. 35,000 lbs over one axle is quite a bit. Can you just set the machine in the shop and use skates or rollers to move it over your slab? Might be cheap insurance against any damage.

I've never moved a machine on rollers, I suppose on my smooth flat floor it would roll fairly easily.
I may have to play it safe and give that method a try. I'll come up with a set of rollers and have them ready on move day.

Mine are 1-1/2" galvanized pipe. Just make sure they are straight!

I don't think the foam makes any difference, but the forklift front axle will add cracks if what's under the foam gives much.

I think there's no way to know what will happen, but if you want to minimize the chances of cracking use skates or pipes and set the machine in the door and roll it into place.

I have 30K+ lb machines on a 6" slab with no reinforcement and all the cracks are in the control joints.

You can also minimize cracks by just having the forklift drive over sheets of steel. Most riggers should be set up for this. It distributes the point load.

cwtoyota said:

I am getting ready to move a VMC into my "new" shop.
I am interested in hearing some input on how much load is too much for my concrete slab.

The details are as follows:

VMC: Kuraki KV-700 VMC (weight is estimated at 12200 lbs)
Forklift: Rental machine 20K - 22K capacity with pneumatic tires. (weight estimated at 22000 Front / 18000 Rear [unloaded])

Concrete: 4000 PSI mix with fiber poured 6" thick over 2"(R-10) Foamular XPS 250 foam. (just over 2 year old slab, so it's had time to cure).

Re-mesh is #9 x 6" and is about 1.5" - 2" up from the bottom of the slab covering the entire area.
Rebar is #4 bar (1/2") on a 18" x 30" grid where the machines will sit, but I have to drive across the middle of the shop that has #4 re-bar on a weaker 76" x 60" grid.

This is a monolithic slab with turned-down footings (no foam under footings). I reinforced the area in front of the 12 x 14 door with an extra 38" x 22" grid of #4 bar extending 40" into the field to prevent that transition across footing to field from breaking.

The reason for the XPS foam insulation is that this is a radiant heated slab with a grid of 1/2" pex on 12" centers.

I'm not asking for engineering (in spite of all the detail) just your experiences with how worried I should be about this.
Is driving a heavy forklift with a 12000 lbs load into my building something I should even be considering?

This is my first thread here, although I've been reading things on the board for years. Hopefully my post adheres to the rules.
Thanks in advance for any input you guys can give!

Click to expand...

the calculations can be made using the formulas provided Owens Corning

http://insulation.owenscorning.ca/assets/0/188/1c2c8d2d-4fe5-4038-970c-9028b3af7414.pdf

you are probably OK but it never hurts to check the math. The VMC sans forklift is a non issue. Maybe just put it on 4 skates and drag it with a smaller lift. or a bunch of guys, offer free burgers or pizza or sumptin. Good thing it is not a lathe, it will settle and the concrete will dish a little where it sits over time. You may have to keep leveling it for a while.

dee
;-D

cwtoyota said:

Is driving a heavy forklift with a 12000 lbs load into my building something I should even be considering?

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Without even bothering to 'engineer' it, I would not.

Bean-counter math is simpler. Gambling risk/reward.

Extra cost of more professional / experienced bonded & insured riggers and wot they do to be CERTAIN of the job, is less than cost of having to deal with downtime and repair of damage to a large underfoot structure already equipped with other machines involved in trying to hit deadlines and earn a living. Not to mention people-injury risks, "key man" and/or skilled trades maybe, and lost productive hours, probably.

Only 'pipe' involved should be laid to the Lady Wife after it is already over with in celebration of a job well-done with no damage or injury.

Contract riggers need not be involved in that part.

Bill

Straight! That's good advice right there.

How "easy" is it to turn a machine when rolling on pipe? I can imagine how guiding it by placing the rollers at an angle works.
Rotating the machine to square it up with the shop walls, once in position, seems like it might be a tough task.

cwtoyota said:

Straight! That's good advice right there.

How "easy" is it to turn a machine when rolling on pipe? I can imagine how guiding it by placing the rollers at an angle works.
Rotating the machine to square it up with the shop walls, once in position, seems like it might be a tough task.

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'Pipe' is deceptive. Even solid bar stock. You look at either and see what you think is a long cylinder spreading load across four feet or more of span.

Unless your load is a solid, flat-bottomed load of steel plate, it is not so doing.

Most machine-tools have a ledge at the bottom of a casting skirt, or rails under weldments. Neither are ordinarily flat and full-width. Skids are obviously only where they 'are'.

Load concentrated there at an edge or under a rib or skid onto a 'pipe' - ever-deforming FROM a cylinder, hopefully recovering - usually - only APPEARS to be transferred the length of the pipe.

In fact, is isn't strong enough to carry that weight and simply springs to follow the deck with only a fraction of the force spread along the length. Most force is actually being transferred at the points right under where the pipe is itself being loaded.

Enter rigger's 'skates'. They place the load where you SEE them place the load. No mendacity.

IF/AS/WHEN that load is too highly concentrated, add more skates, and/or add grillage and/or plates between them and the deck.

Day Job rigger has all this stuff, brings what is needed for the job, has extras, has a 'plan B' and 'plan C' as well as 'plan A', is in, out, gone and safely so while the amateurs are discussing more clever ways to break shit or hurt themselves.

It is, after all, how they pay THEIR mortgage. Most don't operate machine tools.
Return the courtesy. Do what you do best and are already expert at.

Count on them to do the same.


Bill

Haha! That was both realistic and entertaining. Thanks BIll. I don't have a wife, but there is this one woman...

I am not convinced on the pipe rolling, but I am leaning toward owning a set of roller dollies designed for this purpose. They would be a solid investment that I can use for future machine moves. What's that Henry Ford quote about tooling? '...you'll find you have paid for it twice' or something to that effect?

cwtoyota said:

Haha! That was both realistic and entertaining. Thanks BIll. I don't have a wife, but there is this one woman...

I am not convinced on the pipe rolling, but I am leaning toward owning a set of roller dollies designed for this purpose. They would be a solid investment that I can use for future machine moves. What's that Henry Ford quote about tooling? '...you'll find you have paid for it twice' or something to that effect?

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I buy the Northern Tool Orange AND Purple skates often - watch for the times they go on sale.
They are not high-grade Hilmans, but I no longer need them to be.

Lot more rigging gear around here, but there was formal training preceding. And then I taught a bit of it. I still 'can' do, but mostly I hire it done myself. Other folk who do it more often, especially for money, will always have more and better equipment, broader and more current experience.

And the insurance and bonding thing? That is FAR from trivial!

We always ass u me the best. Sometimes there are broken backs instead.


Bill

Bill, I suppose you are referring to these with the polymer wheels?
They look good from here...

http://www.northerntool.com/shop/tools/product_200342863_200342863
http://www.northerntool.com/shop/tools/product_200381531_200381531

I appreciate the sound advice to hire out this move, but that's not in the picture on this one. Safe practices and proper equipment are in the picture.

cwtoyota said:

Bill, I suppose you are referring to these with the polymer wheels?
They look good from here...

http://www.northerntool.com/shop/tools/product_200342863_200342863
http://www.northerntool.com/shop/tools/product_200381531_200381531

I appreciate the sound advice to hire out this move, but that's not in the picture on this one. Safe practices and proper equipment are in the picture.

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Those are good. Heaviest load here is under 6,000 lbs, so I use the cheaper ones so I can afford MORE of them:

http://www.northerntool.com/shop/tools/product_200356890_200356890

http://www.northerntool.com/shop/tools/product_200356891_200356891

I also have a pair of these:

Vestil Steel Prylever Bar | Lever Dollies| Northern Tool + Equipment

Plus bottle jacks, all sorts of stackable shims, and a pair of HF and other-brand low-profile automotive garage jacks, more pry bars, levers, and wedges than I can keep track of... cordage, winches, chains, ratchet straps.. All handy stuff for getting the skates UNDER and removing them afterwards.

They have all worked well, too.

Old thread on PM where we looked up the bearings used as wheels on the orange ones, figured the load limit had to be the point at which the steel axles bent or sheared off, because the bearings used were good for somewhere over 40,000 lbs. combined.

There are books on rigging, actually. Also some good - and a few BAD - examples on PM with photos.

Rigging isn't complicated on this if you keep it right down low and skate it. The skates can be 'steered' with a simple bar, even smacked into a new line with a deadblow hammer or relieved of part of the load with a jack or toe-jack and positioned more gently.

Don't ass u me that 'gravity' is all you need to keep a skate where you placed it, either. Fasten the buggers even if you have to drill holes or cut some chain. WATCH them or assign a watcher to shout-out any misbehaviour right away, Scotch the load, go look.

Once you've had the pleasure of working with proper skates, the only place for 'pipe' will be as previously suggested.

One just DOES NOT go back to all that pain and struggle to place, aim, recycle pipe leaving at rear to get it back under at front... lose copntrol over six helpers, then lose control over the load and have the heavy bastid make its own decisions.. all monkey-motation that is just NOT on. ONE experienced guy simply chases all the gawkers off to a safe distance and does the do, slow and steady.

My rule? If you break the equipment, break your tools, break skin, or even break a SWEAT .. you are doing it wrong.

Easy does it, and even an Old Fart dasn't breath hard, let alone sweat.
The equipment does the WORK. You just do the thinking for it.

Keep in mind one of your goals is no IMPACT loads. Keep the deck CLEAN, pre-bridge any joints and divots so they do not lead to shock loads, go slow ALWAYS, 'creep' do not rumble, have pre-cut Scotch blocks in hand, more in pocket to kerb a potential runaway before it gains ANY speed.. etc.

The skates are also sooo handy to have around afterwards for all manner of stuff that comes up you'll not only consider them a wise buy, you are likely to buy MORE!

Bill

Skates are nice but I've had good success with 2" bar stock. Next time I'll use steel runners though. This bar mill weighs 22,500 lbs.

I have moved my little 1200 lbs Clausing lathe on some rolling dollies, so I can understand how handy these roller-skates will be to own.

RBDJR59, Even with four rollers under each piece of dunnage, I can see them biting in to the wood and having a braking effect.

I'm onboard with the roller-skates plan. This machine has 6 leveling bolts (20mm dia). I have 6 steel foot-plates with 3/4" pockets spotted into them. I'll whip up another batch of those that key up on top of the skates.

Thanks to all of you guys fork basically talking me out of the forklift going on the concrete.

rbdjr59 said:

Skates are nice but I've had good success with 2" bar stock. Next time IView attachment 177912'll use steel runners though. This bar mill weighs 22,500 lbs.

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If you remove the timbers the mill will roll much easier.

I used 1 1/2" solid hot rolled bar to move my 14,000# DeVlieg into place. I could roll it easily by myself. A couple of other bonuses for me using 1 1/2" rollers is 2 x 4's for cribbing match the height of the rollers and I have a machinery bar that lifts 1 3/4 when flat on the floor, which is just right to lift the mill to reposition the rollers.

Try shifting 2" solid rounds around vs the pipe and my bet is you will be setting the heavy stuff aside and just get on with moving your stuff. I have no complaints with the pipe, although my mills only weigh 8000 lbs. I don't care if the pipe flexes and doesn't distribute the load evenly over it's 4' length, I am using them on a concrete slab, not a dirt floor. Before I acquired the 1-1/2 pipe I used 1/2" galvanized pipe that came out of my house after some remodeling. It worked too but didn't roll as easily. Since I only move machines around every 3 to 6 years I feel the $$ is better invested elsewhere, plus I don't mind storing the pipe outside in the weather.

The machine will pivot around just fine, as long as your rollers are positioned correctly. One required item to make the pipe work is a good pinch bar. I also got a low profile floor jack for the last move which made life a lot easier, it works great for cars as well so that helps justify the expense. One last thought is I like to keep heavy loads as close to the ground as possible when moving them, not much can happen when it's only 1-1/2"s off the ground. How tall are your skates?

DavidScott said:

Try shifting 2" solid rounds around vs the pipe and my bet is you will be setting the heavy stuff aside and just get on with moving your stuff. I have no complaints with the pipe, although my mills only weigh 8000 lbs. I don't care if the pipe flexes and doesn't distribute the load evenly over it's 4' length, I am using them on a concrete slab, not a dirt floor. Before I acquired the 1-1/2 pipe I used 1/2" galvanized pipe that came out of my house after some remodeling. It worked too but didn't roll as easily. Since I only move machines around every 3 to 6 years I feel the $$ is better invested elsewhere, plus I don't mind storing the pipe outside in the weather.

The machine will pivot around just fine, as long as your rollers are positioned correctly. One required item to make the pipe work is a good pinch bar. I also got a low profile floor jack for the last move which made life a lot easier, it works great for cars as well so that helps justify the expense. One last thought is I like to keep heavy loads as close to the ground as possible when moving them, not much can happen when it's only 1-1/2"s off the ground. How tall are your skates?

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*yawn* No need to sell the idea. Been in use a long time:

Moving the Stones of Baalbek–The Wonders of Roman Engineering | Fleeing Nergal, Seeking Stars

Some of us have just gotten LAZY and moved-on to lower-sweat methods...