Two post slab requirements

[CamarosRus]

I dont know how to properly use the web sites search function to locate
past threads discussing slab thickness, cutting my 4" concrete installing rebar and studs for two post install.........

 

[mrgm]

what lift is it?
here is kind of a start. they will be almost identical depending on model
http://www.mohawklifts.com/consumer/library/Slab_Req-Reco_2-2010.pdf

 

[Randy in Maine]

My Bendpak 10K pound 2 post lift requires 4" of 3000 PSI concrete. I am going a bit heavier with 6" of 4000 PSI concrete since this was new construction. No radiant floor heat will be installed 4' all around the area of the posts.

 

[synik]

Most 10k 2 post lift, require at least 4" slab with rebar. Then to be drilled and anchor bolts would be installed AFTER your pour the concrete (once cured 30 days recommended by most lift manufacture).

Check my sig, I went with 4x4 feet and 8 inch deep for my 2 post lift area, with two layers of rebar. Went overboard with twice the requirement.

Make sure you drill and have rebar tied into your existing slab with concrete epoxy.

 

[CamarosRus]

I was told by contractor who built (above) shop that slab was 4" thick, but I have no other reliable details.

How can I have tested or otherwise evaluate the psi of my slab.

Wanting to find out ASAP if my slab will be OK for 10K two post (and four post) or
if in fact I need to bring in concrete cutters and go through entire process of building up
floor.

Thanks for the education

 

[mrgm]

I would ask him if he could pass you to the concrete guys who did the pour, they would have the info you need.

 

[CamarosRus]

General ccontractor who framed and finished my shop told me cement guy had passed away !!!!!! so no one that really knows my concrete history.

For some reason I have a 30 x 46' one piece slab (NO relief cuts or expansion joints) with no cracks ????????

 

[SiGmA_X]

OP, IF your 4" floor is 3000psi (I imagine it is just that) and HAS rebar, you're ok. If it does NOT have rebar, or doesn't have much, you need to pour a lift slab for a 2 post. My floor (rented shop) was like this. We cut out 15x4 and poured 9" of 4500psi, with, shoot, 180ft of 5/8" bar I believe. Many manufactures suggest two 4x4x6" pads, I would without a doubt do a connected slab, and I would do 8-12" deep. Look at the Mohawk PDF, they are the best out there. I had a mechanical engineer give me the go ahead to do lesser, by his calcs a 6" floor would have been more than enough, but he also is the lets do more type of guy. My friends got tired of digging around the ~9" point.

Let someone else chime in, as I have minimal knowledge about this stuff, but if you have a crack free slab that big.. Its pretty fair to guess you have a bit of bar in there...

 

[CamarosRus]

Without cutting my crack free slab how can i tell anything about its makeup??

Guess i should just plan on cutting digging rebar etc etc

Where can i find thread on placement suggestions in my 30 x 45 shop with 22 foot door on one end.
Also want one or more four post for storage
Should i put two post dead center by door or off to one side
So many possabilities so many ideas

 

[LegacyIndustrial]

Chuck:

This is not my expertise. However, we often do core samples in the epoxy business.
See if you can rent a drill and bit intended for this and have the core examined by a pro.

 

[SiGmA_X]

Legacy, I don't think that will show what actually matters - the amount of rebar in the concrete. I'm sure its a 3000psi slab, people don't pour lower psi slabs much/ever.

Chuck, rebar wise, I think the only way to find out is to talk to the builder... Placement wise, that's all up to you man! Do you have a floor plan of your shop? Where are your benches? Where do you park cars? I'd put the 2 post in a bay, you only need about 4ft on either side of the vehicle, my hoist post is about 30" away from the wall. Forward clearance is more tricky, if you have built in benches. Its all up to the length of the vehicle you rack in this case, and the type of hoist you buy.

 

[Rentawrench]

Find someone with a Good metal detector( Underground pipe utillity contractor )and sweep the floor with to trace the rebar location.

Then like Legacy said core drill an area under the work bench so it will not show , an have the core tested for the psi rating. Do this first an you might find the floor has a fiber renforcement .

The 4 post needs very little an looking at your Great shop any where you want to place it would be fine.

 

[SiGmA_X]

Rentawrench, you think a good metal detector will do it? I thought about that option but it doesn't show bar size. I suppose it'd be at least 1/2" and if its every 12" it should be fine regardless prolly.

 

[RaceDeck1]

If that slab was built to code, you should have not issue. In one of our shops I have the 10,000 lb Benpak and it was installed on a 4" slab, its been there for almost 8 years with no issue.

 

[CamarosRus]

My shop and slab was permitted and inspected in King County WA State
I'll check with the county on what concrete specs should have been.

Dont know how much pro concrete cutting costs but Im soon
To find out

 

[RaceDeck1]

That is a good idea, I would just Google what your County Code is for concrete and all related.