Lift question

[strange246]

Not sure if this is the right place to post this but here goes, just bought a Mohawk 2-post lift, used but in perfect working order, got it for cheap from a family friend shutting down his used car business, anyway, I'm planning on putting it in my home garage, I have plenty of ceiling height (12'), and floor space (24x30) to do it, my concern is the floor, it's a 4" thick floor about a year old, not sure if it has rebar in it, the underlayment was done right and packed solid as concrete before the actual concrete was poured, now Mohawk's website reccomends 4.5" thick concrete but I'm not going to sweat the missing 1/2" but what really is making me wonder/worry is that there are 1-inch deep "stress grooves?" cut into it, in other words there is a 3/16" groove cut 1 inch deep down the middle, front to back of the floor, and 2 going cross-wise, one is about 10 feet in from the front of the garage, and the 2nd one about 20 feet in, should I worry about them?? The lift is going to be mainly used to work on a Dodge Demon and Plymouth Duster, both are around 3,000-3,200 pounds max, but I'd like to put my wife's Durango on there without worrying about the floor giving way..Thoughts? Suggestions?

Ryan

 

[OldCarGuy]

Congratulations on you new toy. You are going to love it.

It would be best to ask the manufacture your concerns about the saw cuts. From what I understand keeping the base of the columns 12" away from the saw cuts would be a good idea.

 

[dawg]

if it was me I would cut out the floor in the area under the lift pads and reinforce with rebar and reinforced concrete.
(this said not knowing what grade of concrete you have)
Its better to be safe than sorry !

 

[Franz©]

Well, some times life gives you situations that would be nicer, IF, but if ain't gonna happen.

I know of quite a number of hoysts sitting on 4" pours and none have broken thru yet, or pulled out. The simple reality is the spec for 6" floors exists because the manufacturer built the hoyst with a small footprint.

It's very easy to increase the footprint by adding 4 feet of 3" x 5" ½" angle iron that is welded to the existing colum and baseplate. That comes near to tripling the footprint, without loosing floorspace you'll notice.

Personally I believe the added angle makes the hoyst's overall weight distribution to the floor better.

 

[strange246]

Awesome, just got off the phone with Mohawk, they say the lift I bought (Their older System II 6,000LB) will be fine on my floor as long as it's 4-4.5 inches and the expansion joints are fine if I stay 6" away from them, now I just have to go pick up the anchor bolts they want me to use at $60 for 20...

Ryan

 

[Yotaforce]

I spoke with my concrete contractor about it when I had my slab poured and we agreed that when I do get my lift and know EXACTLY where I want it, it would be a good idea to cut out 2' squares, dig down about 24", insert rebar reinforcements, set lift anchorbolts in a template board, and refill holes with reinforced concrete, building "lift footers" to compensate for my 4" slab. I could've done this when the concrete was poured, but you know how when you move into a new shop, you really don't know where you want anything until it's all in there.

 

[brownbagg]

I would also epoxy rebar into existing slab too. for tilting purpose

 

[Danglerb]

I spoke with my concrete contractor about it when I had my slab poured and we agreed that when I do get my lift and know EXACTLY where I want it, it would be a good idea to cut out 2' squares, dig down about 24", insert rebar reinforcements, set lift anchorbolts in a template board, and refill holes with reinforced concrete, building "lift footers" to compensate for my 4" slab. I could've done this when the concrete was poured, but you know how when you move into a new shop, you really don't know where you want anything until it's all in there.

When looking at site prep on several brands of lift the FAQ says don't put bolts in the cement.