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Saw somewhere on their site 4" is min pad depth for HD9.
What do you guys have? Less than 4"?
Looks like one of my posts will be on 3.5" concrete depth +/- 0.25".
I wouldn't worry with any 4 post lift, unless you plan on bolting it down at the post with the thinner concrete. Personally I have mine floating and it has been fine for 5+ years. Plus I'm in a Mattamy house so I'm sure my slab is thin LOL, but I never checked.
I wouldn't worry with any 4 post lift, unless you plan on bolting it down at the post with the thinner concrete. Personally I have mine floating and it has been fine for 5+ years. Plus I'm in a Mattamy house so I'm sure my slab is thin LOL, but I never checked.
No intention on bolting as I don't think it's required. Pretty sure mine is Mattamy from 1985 and the pad depth varies throughout the garage.
No intention on bolting as I don't think it's required. Pretty sure mine is Mattamy from 1985 and the pad depth varies throughout the garage.
You can calculate your load per sq inch by using the size of each base plate plus the lift and car weight. Your base plates should be 10" x 12" on the HD9, for a total of 480 sq inches of contact. Add up your total weight and divide by 480 to get your load per sq inch. IIRC mine is about 15lbs per square inch, and I have huge crack that runs under two posts (was there before the lift).
Keep it simple. I park my 5500lb SUV in my garage on 4 tires with a total area of maybe 80 sq inches . My lift has 4 10x10 inch pads for a total of 400 sq inches. I am not worried a bit. If I was really **** I could lift the lift and squirt some PL under the corner pads so the weight is evenly distributed due to any concrete surface irregularities
You can calculate your load per sq inch by using the size of each base plate plus the lift and car weight. Your base plates should be 10" x 12" on the HD9, for a total of 480 sq inches of contact. Add up your total weight and divide by 480 to get your load per sq inch. IIRC mine is about 15lbs per square inch, and I have huge crack that runs under two posts (was there before the lift).
Your assuming 100% of the base plate is making even contact with the floor. I highly doubt that. To the OP. I wouldn't worry about it. It will be fine. Don't forget there is ground under that concrete. It's not floating. I hope. Mine has been fine for 13 years. Subdivision home.
Your assuming 100% of the base plate is making even contact with the floor. I highly doubt that. To the OP. I wouldn't worry about it. It will be fine. Don't forget there is ground under that concrete. It's not floating. I hope. Mine has been fine for 13 years. Subdivision home.
When I installed mine I used a straight edge to find the optimum location on the pad and then marked those spots for the installers. But yes unless your concrete is ultra flat these calculations are just a guide, not exact.
If I did it all over again I would put a thin sheet of PVC or something (with small grooves for drainage) under the feet to keep water from getting trapped and rusting the underside.
My DirectLift is not bolted down. In fact, it's sitting on top of Racedeck tiles too. Zero issues and I've had my 4Runner which is a lot heavier on it as well as the car.
Your car sat on the floor with its 4 tire contact patches and did not break the concrete. The 4-post lift won't be any different.
Agree that in bolting it down a little thicker concrete would be nice if you have any expectations of the bolts holding the post steady should there be any events while using that could rock or tilt the lift (such as the platform coming down on an angle), but if left floating, your existing floor should be just fine. Lift posts have to be 100% plumb.
Be sure that your garage floor is level.
Installed a Bendpak about 5 years ago and didn't think to check (4" from back to front)
Had a pro do the installation so he was able to elevate the one end. Rendered the ramps useless as the pitch was too great. Had to make my own to load my cars.
Have a rear door on the garage so was able to use them on the other end.
I should have done a bit more homework, although it all worked out in the end.
Be sure that your garage floor is level.
Installed a Bendpak about 5 years ago and didn't think to check (4" from back to front)
Had a pro do the installation so he was able to elevate the one end. Rendered the ramps useless as the pitch was too great. Had to make my own to load my cars.
Have a rear door on the garage so was able to use them on the other end.
I should have done a bit more homework, although it all worked out in the end.
Don't all garage floors have a slope? Drainage? Mine has a fair bit. My Rotary Evolution lift has adjustment for this built in to its design. Probably about 4".
I would assume all lifts would have a certain degree of adjustment for level. In my case the floor grade exceeded the max adjustment requiring the plates beneath the front posts. Just wanted the original poster to be aware (which I was not) before getting his lift.
Keep it simple. I park my 5500lb SUV in my garage on 4 tires with a total area of maybe 80 sq inches . My lift has 4 10x10 inch pads for a total of 400 sq inches. I am not worried a bit. If I was really **** I could lift the lift and squirt some PL under the corner pads so the weight is evenly distributed due to any concrete surface irregularities
Interesting way to look at it. What is PL?
Originally Posted by Greg981
Your assuming 100% of the base plate is making even contact with the floor. I highly doubt that. To the OP. I wouldn't worry about it. It will be fine. Don't forget there is ground under that concrete. It's not floating. I hope. Mine has been fine for 13 years. Subdivision home.
This is likely true in my garage. I haven't gone over the floor area where the posts will land to check for imperfections. I do know parts of the pad have lost it's smooth surface. Even if smooth, may not be level. Will explore that further. Funny you say that, an engineer I was speaking with about truss modifications mentioned the same thing. You may get spider cracks but lift won't fail. Apparently my pad has good mesh underneath and is in good shape for the age.
Originally Posted by XYXXXY
I would assume all lifts would have a certain degree of adjustment for level. In my case the floor grade exceeded the max adjustment requiring the plates beneath the front posts. Just wanted the original poster to be aware (which I was not) before getting his lift.
I didn't think the HD9 had room for adjustment on the posts, believe they are solid fixed posts. IIRC the manual says 3 degrees of slope is acceptable.
03-29-2018, 03:19 PM
BendPak Lift - Concrete Pad
