Install Maxjax on 3.5" concrete base

[riderosa]

I have read many of the previous posts on bolting down the MaxJax but they don't seem to give me the information I am looking for. I installed using Wejit inserts in my previous home and it worked great but my new home garage has only a 3.5" concrete thickness.

Do I have any other options other than to cut out slabs and re pour? Since my installation will be permanent does this open up some possibilities?

 

[matt_i]

My personal opinion is that epoxied anchors, when done correctly and all of the prep procedures are followed, are superior to wedge-style anchors. They get used on critical anchorage fasteners for industrial robot bases, jib cranes, and other heavy machinery which is also more or less permanently installed until its useable life is over.

To me the prep involves getting a bottle brush as deep as the hole is going to be, getting an compressed air blowgun with a thin nozzle as long as the hole is going to be, and sourcing Grade B7 threaded rod (approximating a Grade 5 bolt in tensile strength). Can buy that at McMaster Carr.

 

[GMCGarage]

From their website:
1. Concrete Specifications

The floor on which the lift is to be installed must be 4-inch minimum thickness concrete
Must have minimum comprehessive strength of 3,000 PSI
Must be installed on solid level concrete with no more than 3-degrees of slope


Thats all they have. If you cut out your slab, it does not say if you need to cut out 1'x1' or 10'x10', so I would assume they expect the slab to be all 4".

Not sure how big the slab needs to be. What if you only had a pad, and it was 5'x5' each side?

They are very good at not taking any responsibility for the anchors on down. Buyer beware, and make it stout when in doubt.

 

[riderosa]

Thanks for the feedback.

I am considering using 3/4" Red head wedge bolts. Using the baseplate as a drill guide I would drill a 3/4" hole about 3" deep into the concrete and assemble using a nut and thick washer on the threaded 3/4 " threaded stud that sticks out. It is pretty permanent but I don't plan on moving it.

The idea of pouring a pad over existing concrete is interesting!

 

[GMCGarage]

Thanks for the feedback.

I am considering using 3/4" Red head wedge bolts. Using the baseplate as a drill guide I would drill a 3/4" hole about 3" deep into the concrete and assemble using a nut and thick washer on the threaded 3/4 " threaded stud that sticks out. It is pretty permanent but I don't plan on moving it.

The idea of pouring a pad over existing concrete is interesting!

Looks like the requirements for that anchor is 6" min slab and 4.75" deep hole. Not sure how I would feel about reducing the requirements and my life depending on that.

 

[c4cruiser]

Before I started the install for my MaxJax, I decided to drill some test holes to make sure that the actual depth of the concrete floor matched the specs I was shown by the contractor. The plans called for a 4" minimum thickness using a minimum 3000psi mix. Turned out it was waaay wrong Every hole i drilled showed to be no thicker than 2.5".

So I decided (after reading a number of threads about hoist installations) to replace two sections of the garage floor and have two 4'x4'x12" slabs poured using a 5000psi mix. These slabs were tied into the existing floor with rebar and the new surface was smoothed out to be level.

That cost a fair amount of money to do, but I got a very solid surface. I used 7" long epoxy anchors. It took some work to prep the holes for these anchors, but I believe that they are stronger than needed. Guess I wanted to be safe...

For the OP, I would recommend pouring a new slab for the install. The 3.5" depth is not really enough and you should also check for any cracks in the current floor. MaxJax install instructions that came with my unit also mentioned to not install any anchors that would be within 6" of any cracks in the floor.

In some of the MaxJax threads, there are pics of what people did for their install.

 

[garagelogician]

I was looking at MaxJax for awhile, but my concrete varies in thickness and has some cracks. I do not want to go through the expense and work of pouring new pads, so I am opting for a 4 post lift. I am not willing to risk my life and well-being on concrete that does not meet spec.

 

[riderosa]

What about pouring a slab; say 4' x4' x 3.5" over the existing floor?

 

[petee_c]

I cut out two 3x4' sections of 3.75" garage floor and dug down to about 12" and repoured...

Added about $500 cost to the install.... (minimum charge for the 1 cu yard of concrete)

That was about 6 yrs ago....