If I have to jack hammer the floor

[AbitNutz]

If I don't have enough pad depth to make me happy, wouldn't it be smarter to saw out a 3'x3' section where each post would go. Then dig down about 12" to 18" inches; tie in as much rebar as possible and then attach "J" studs to the rebar and up through the pad and sit the posts on those?

That would get rid of any possibility of studs pulling out. I think if I were pouring a new floor, wouldn't that pretty much eliminate the studs from pulling out? After all, they're not being held by just the concrete, they'd be hooked through the rebar.

 

[wssix99]

If you are putting in a lift, the answer is definitely not!

The thickness required in the concrete is for bending of the floor when the lift is loaded and not for the weight it is carrying. (If you look at the lift from the side, the posts make a "T" with the concrete floor and its the legs of the "T" that go in to bending when the lift is loaded.)

If you don't have the depth in your slab for the lift, you can put in pads, but they'll need to be larger than 3'X3'. (Otherwise, they could tip right out of the floor.) I recall seeing pad specs in a Mohawk manual but haven't seen them for other manufacturers.

 

[AbitNutz]

I think I'll consult an engineer before I start believing that I know what I'm talking about. But what if instead of just cutting a 3x3 squares under the posts....what if I cut 3x whatever between the posts and connected them with rebar and concrete? In all honesty, that wouldn't be much more work.

 

[nehog]

As for size and technique, contact the lift maker. Meet their requirements and you'll be OK.

 

[DekeT]

I think I'll consult an engineer before I start believing that I know what I'm talking about. But what if instead of just cutting a 3x3 squares under the posts....what if I cut 3x whatever between the posts and connected them with rebar and concrete? In all honesty, that wouldn't be much more work.

That would help with bending between the posts but not with bending stresses at a right angle from the line of the posts. I think you would have to drill the slab and set rebar before you place the new concrete to achieve a good connection with the rest of the slab.

 

[Strouty]

Most lifts require 3 1/2" to 6 1/2" so unless you have just a topcoat you may be ok.

 

[wssix99]

+1 for contacting the manufacturer. Their engineers have set parameters for these things and their engineers should be free to you since you are purchasing their product.