Getting ready for two post lift.

[cthulu]

I'm finally pulling the trigger on a lift.

Picking up the RTP9-9000 as it is the only ALI certified lift that works with a 10'6 ceiling.

http://www.revolutionlift.com/RTP9-9000-Pound-Capacity-Two-Post-Lift-P1C3.aspx

http://www.autolift.org/ali-directo...roductbrand=All&rateload=&searchsubmit=Search

Did a fair amount of research on this and 10ft ceilings aren't uncommon, so maybe this will help someone out.


Cutting two 4 foot by 4 foot holes in my 2.5in pad on Sunday then digging everything out 5 inches and some along the underside of the 2.5in pad. Then having a guy out to pour as soon as I finish.

How long does everyone think I should wait after the pour to install the lift? I've seen between 48 hours to 4 weeks listed as cure times.

How long has everyone else waited until they installed the lift?

 

[sleek98]

If it was me I would wait the full 28 days. Nothing more unsettling that standing under 5k pounds of car that is in fresh concrete....

 

[dave89iroc]

as long as you possibly can, the full 28+ days if at all possible

 

[rburke65]

I would not feel comfortable with the 4x4x5" pads especially tying it into a 2.5" floor. I would do a 12' long by 4' wide by 12" deep. Even that would be less than 2 yards of concrete. Just me but........ It just don't seem to be a lot of mass to me. IMO. Good luck. You will like your lift.

 

[Walter_TA]

I like the 4 x 12 better than two holes. Make the concrete at least 12 in deep. Concrete cures to 80% or so in the first week. I would say let it set for a min of two weeks. Keep the concrete wet for the first week. Get 4000 PSI concrete. Get a ton of rebar to use in the pour and run it under the existing concrete from one side to the other. So get an 8 foot length and run it two foot under the existing concrete on both sides. Use plastic on the bottom of the hole. The concrete will cure better. Did I say keep it wet the first week. That can add alot of strength.

 

[brownbagg]

as it is the only ALI certified lift that works with a 10'6 ceiling.

no, bend pak has one too. and by no means am I saying bend pak is better, no not me.

 

[brownbagg]

Cutting two 4 foot by 4 foot holes in my 2.5in pad on Sunday then digging everything out 5 inches and some along the underside of the 2.5in pad. Then having a guy out to pour as soon as I finish.

no, dont do that, go to the rotary site and follow what they says, me i would do ten feet by ten feet about five feet thick, you little four by four will tilt right over. Me, i would really put ten yards under it for counter weight, your slab not going bond with your little 2.5 slab

 

[cthulu]

Thanks guys, finish cutting it today. Pad will be 4ft by 14ft, digging down a foot and using rebar with a thick plastic sheet sitting above some packed gravel.

Speaking with lift manufacturers they say go 3k PSI so that's what we are pulling the trigger on as soon as we finish cutting it and pulling the old stuff out. So far a wet saw with a depth of 4in hasn't seemed to go all the way through..so it looks like the places I checked thickness were bad or I did it wrong (Drill until it pops through, measure drill)

Looking like the slab may be 4-5 inches afterall..and has rebar...likely didn't need to cut at all. Guess I should have drilled closer to the center.

 

[matt_i]

I would edge-dowel (iow drill holes into the thickness of) the existing slab, then put in rebars to make sure the two don't misalign on you in the future.

 

[Diesel Dan]

Looking like the slab may be 4-5 inches afterall..and has rebar...likely didn't need to cut at all. Guess I should have drilled closer to the center.

Is this where the age old saying of "measure twice cut once" applies?

 

[cthulu]

Good thing I cut the old slab, the concrete was poured so evenly that it was 2.5-3 on one side of the 4ftx15ft cut and 5 inches thick on the other side.

I have it dug down 13 inches and a 6 inch key all around the 4ftx15ft cut.

The old slab I cut into didn't have any vapor barrier or gravel down, it was just poured on top of the earth and they didn't do anything to hold the wiremesh up so parts of it aren't even in the concrete.

Planning on the new pour to meet the more stringent mohawk requirements below (12in of concrete, 6in key around existing slab)

http://www.mohawklifts.com/library/manuals/Slab_Require_Recommend_11_07.pdf

I tamp the **** out of the existing earth then the vapor barrier goes down first, followed by 2 inches of 3/4 washed gravel right?

Some people are saying to use sand, others are saying to avoid it and go with the 3/4 washed gravel.

 

[rburke65]

Just my opinion, but I would NOT use sand.

 

[Diesel Dan]

Depending on region, sand is a normal fill material with good results.

 

[cthulu]

Can't seem to find 3/4 cleaned rock anywhere, did find 5/8 crushed clean rock. I would imagine this would work well?

http://www.burienbark.com/products/rocks-gravel-sand/

 

[Diesel Dan]

Opps, wrong thread.