Anyone have any garage floor cracking problems from a lift ?

[twinvipers]

Installing my lift(Revolution) this week. A few people have mentioned that the floor might crack. Anyone have this happen ?

 

[Fred(DrivingSchool)Kinder]

The thickness and quality of the concrete is important.

http://www.bendpak.com/custom_page.isg?ref=bpakconcretereq

 

[SNKEBIT]

If your floor cracks, it's not thick enough for a lift. PERIOD!!!!!!!! Either get rid of the lift or tear the floor out and pour a thicker one.

 

[94RT10Ohio]

If your floor cracks, it's not thick enough for a lift. PERIOD!!!!!!!! Either get rid of the lift or tear the floor out and pour a thicker one.

That could be quite costly. Depending on how much you "love" your floor, you could cut out a few sections and repour just those sections saving $$.

 

[Jack B]

Thickness is just one element, you must have the proper fill underneath the concrete. The above post was right on, merely use a jackhammer and remove four setions of approximately 2' x 2' and pour yourself some quasi-footers. On the other hand the point loading is no different than the car exerts via the tires.

 

[Un'sidepiper]

There are a lot of elements that make a strong concrete floor:
1. The thickness of the concrete is not everything, what is important is the concrete mix design, all concrete is designed to meet a certain psi rating. If the psi of your floor is less than the load of the lift and the car, the floor will crack.
2. It is not a good idea to just pick up a jackhammer and go to town, you may damage rebar, post tensioning cables, etc. If you do this you will compromise the structural integridity of you slab which is far worse than any damage that may be caused by the weight of the lift. A pacometer test can be done to find location of rebar. (similar to a bone x-ray) What ever you do - do not damage any rebar!
3. The compaction is also very important as mentioned by Jon B, Chances are underneath your slab you have an engineered fill such as decomposed granite which is a typical underslab material. My guess is this is not your problem.

My first step would be to track down a set of As-built drawings for your house this will tell you exactly what you have; slab thickness, psi rating, underslab material and thickness, rebar location, PT cables (if any), footing locations, thickened edges etc. Then compare this data to the requirements of the lift company.

Also contact a structural engineer in you area and pick his brain over the phone!

Good Luck!

 

[twinvipers]

I will check with my builder today and find out how thick the floor is. I'm sure it's at least 4".

 

[95Viper]

I don't haver it but if I did see a little cracking, couldn't you consider having a larger pad of steel welded to the original feet of the lift? Maybe twice the size like 10x10" or 12x12?

 

[GTS Dean]

My first step would be to track down a set of As-built drawings for your house this will tell you exactly what you have; slab thickness, psi rating, underslab material and thickness, rebar location, PT cables (if any), footing locations, thickened edges etc. Then compare this data to the requirements of the lift company.

Good Luck!

Yeah, good luck.

Everyone raise your hands if you have a set of "as-built" drawings of your house.

Anyone? Anyone? Bueller?

:crickets:


I agree with the individual footings idea. If the slab is post-tensioned, then it is critical to locate the reinforcement strands before breaking any concrete. I'd go with a 3600 psi 6-sack design and footings about 14-16" square and 30-36" deep with some 12"+ LONG anchor bolts.

 

[Un'sidepiper]

don't haver it but if I did see a little cracking, couldn't you consider having a larger pad of steel welded to the original feet of the lift? Maybe twice the size like 10x10" or 12x12?


----------------------

A larger pad would be great, it would help distribute the weight over a larger area!

 

[Bill B]

Raising my hand. You can go to the city and review a set of your drawings. They may not be as-built but if the city was on top of it they will be accurate.

 

[scottgf]

This may be a dumb question...
If the floor doesnt crack with your car parked there...why would it crack with the lift?
The weight of the lift plus the wieght of the Viper cant be more than something like a Suburban parked on the slab....right???
I would doubt the slab would crack with a big SUV just sitting there....

Cheers,