Lift Footings

[papa_smurf49319]

Building a 30x40x13, two 10x10 doors on eave side, one 10x10 on gable side. Plan on putting 10,000 pound two post hoist in center bay of eave side. Currently looking at Mohawk, bendpak, and rotary. Id love to get a Mohawk but heard they are pricey. Have a rotary at work and love it. Have a few questions on slab requirements. Told builder I need 6-1/2 inch thickness and 4,000 psi. I know this is a bit overkill, but better safe than sorry right? Rest of barn will be 4 inch. Question I have since I don't know which lift yet is footing placement and size? Any recommendations? Also is 13 foot sufficient height. I would go 14' but I don't want the barn to dwarf the house since it is in front and will be visible from road. I can get pics, sketches, similar build barn pics, if anybody is interested.

Thanks for the help

Cody

 

[James-W]

I am no concrete expert so I am only guessing here, but I would think that 6 1/2 inches of concrete for a 2 post 10,000 lift isn't an overkill. I am tempted to say it wouldn't hurt if it was a little thicker, but that is just my personal opinion and is not based on any concrete strength tables or facts.

 

[papa_smurf49319]

Also I am 6 foot tall, is 13 foot ceiling going to allow me to lift a truck or suv high enough and still be comfortable standing underneath?

 

[papa_smurf49319]

Most 10,000 pound hoist are calling for 4 - 1/4" and 3000 psi

 

[BluByU]

I put 6.5 inches down when I put in my Mohawk. I'm 6' 2" and I can lift my Silverado 2500HD and walk under no problem with 12' 6" ceiling height but I have only a few inches to spare to the ceiling.

 

[wssix99]

Have a few questions on slab requirements.

Told builder I need 6-1/2 inch thickness and 4,000 psi. I know this is a bit overkill, but better safe than sorry right?

Overkill - technically, yes. If you put reinforcing in a thicker slab, you need more steel to control the extra shrinkage stresses that will occur with a thicker slab. Adding the extra steel is where it really gets more expensive.

- If you aren't putting any reinforcing in early - no worries except that your saw cut control joints will be 10' apart and you'll want to make sure they stay the required distance from your lift posts.

- If you are putting in reinforcing, your saw cut control joints can be further apart. You'll still want to plan this with your concrete company well in advance, again to make sure your cuts are well clear of your posts.

Rest of barn will be 4 inch.

How are you going to separate the 4" and 6 1/2' sections? Will your lift section be the full pad? If so, you'll need an expansion joint between the two thicknesses.

Question I have since I don't know which lift yet is footing placement and size? Any recommendations?

This is the easy one. You do not want any footers for your lift. Putting them in will cause cracking in your slab and will cause the lift to be weaker. (This is why the lift instructions do not call for footers - footing pads are only used in a remodeling context and not for a new slab.) Flat, smooth slab is your strongest and most durable way to go.

Also is 13 foot sufficient height. I would go 14' but I don't want the barn to dwarf the house since it is in front and will be visible from road.

It depends on the lift. If your lift has a cross bar at the top, you won't be able to go much higher than that bar, anyway. Your limiting factor (because most will have the cross bar at the top) is probably your garage door, how low it will hang down from the ceiling and how it will interact with a load all the way at the top of your chosen lift.

 

[575cat]

4 inch and 10k is fine , too much thinking .

 

[1953mercury]

14' will make for better head room if you are considering loft space (which can clear up a lot of usable floor space). 1' on a building that size wouldn't make much difference. That said, 13' should give you plenty of room for your lift. Mike

 

[papa_smurf49319]

Ok looks like im going with the 10,000lb mohawk system 1. The hoist distributor recommend a 4ft x14ft rectangle pad 6 1/2" thick. How far back from the wall the front of vehicle will be facing should i have footing poured. I want room in front to be able to pull motor have toolbox etc, but i also wanna be able to have a crew cab long box pickup on the hoist and be able to shut and open overhead door. Ill have a 30ft bay to work with

Thanks

Cody

 

[wssix99]

Ok looks like im going with the 10,000lb mohawk system 1. The hoist distributor recommend a 4ft x14ft rectangle pad 6 1/2" thick.

They either:
- Don't know what they are talking about
- Don't understand your situation

There is no need to over think this. All you have to do is follow the Mohawk instructions. (They have engineers who figure this stuff out and I'm sure your distributor is not one of them.)

The instructions will tell you to do the pads for a remodel application, which is not your situation. If you read the Mohawk remodel instructions, you'll see that they will call for keying or pinning the pad into your slab. You could probably do this in a two step pour for your new slab, but it will be weaker than it would be if you just did a monolithic slab and will cause cracking in your main slab. (Stress cracks will form at the corners of the rectangle and radiate outwards at 45 degrees from the shrinkage stresses around those re-entrant corners.)

Best to follow the instructions that Mohawk gives for new slabs. Flat and uniform.

How far back from the wall the front of vehicle will be facing should i have footing poured. I want room in front to be able to pull motor have toolbox etc, but i also wanna be able to have a crew cab long box pickup on the hoist and be able to shut and open overhead door. Ill have a 30ft bay to work with

If you take the weight distribution (front-to-back) of all the vehicles you will put on the lift, you can figure out where the center of mass is for the vehicles. That should be even with the posts and you can then measure from there to figure out what your overhangs are for your various vehicles. (When I did this for my garage, I found that my front heavy truck had a very different position compared to my more balanced cars. The interference of my bed sticking in to the door opening turned out to be my limiting factor. As a result, my cars will stick more forward than I'd like - but I only have 25'. So, I expect you'll have an easier time with 30.)

 

[6768rogues]

I have a 9000 lb. 2 post lift and it required 4 inches of 3500# reinforced concrete. I had 5 inches of 4000# with #4 bars every 2 feet in both directions and fiber mesh, so I simply installed the lift.