Lifts

[Raizinman]

Remember that if you hide the connecting beam in the ceiling, you're assumably disabling the safety feature that keeps you from shoving the car into the roof. Most if not all lifts come with a safety bar across the top that stops the lift motor once the top of the car touches it.

This is true, but on mine, I installed a few mirrors on the ceiling above the lift. This way when I'm lifting a car, I can see the space between the car and ceiling. So far, I've never hit the ceiling.

 

[Raizinman]

Cutting a hole in the concrete and building some peirs inside your slab actually isn't as hard as you might think. You could get the few tools you need from a rental place(quickie saw, rotary hammer, shovel, wheel barrow) and pour them in yourself. Thats how I'd do it.

True, but if you know the type and strength of concrete in your garage you often can get by with a 4 foot by 4 foot 3/4" steel plate to go under the lift post. This will disperse the weight over a 48"x48" area instead of a 9"x9" area. Normally you can get by with this on a normal garage floor.

One other advantage I have found with having a lift in your garage is that during ice storms, tornados, and hail storms, you can get 4 cars in a 3 car garage (putting a car up on the lift and driving one underneath). Living in the midwest and tornado alley, I normally do this a few times a year.

 

[phucheneh]

Mirrors are definitely a good idea. Since you're not racking up multiple cars every day, I would imagine most people would be a little more cautious than someone like me that has learned to depend on that safety feature because of all the damn tall SUV's and such out there.

I'm a tall guy, so I always max the lift if I'm going to be walking under the car. And for those who don't know- it's a mechanical safety feature, so unless your lift is all kinds of messed up, yes, you should be able to depend on it. Just like the mechanical locks, which you should not disable. Stated because, well...lots of people disable them.

 

[Gillbot]

Personally, I wouldn't want two simple small concrete pads poured to support a lift that is going to be holding thousands of pounds over my head. I'd rather have a proper concrete pad designed to support and properly distribute the weight.

 

[SyndromeOCZ]

If your afraid of simple concrete pads holding thousands of pounds above your head then you better stay out of walmart buildings... 😉 😛

 

[Gillbot]

If your afraid of simple concrete pads holding thousands of pounds above your head then you better stay out of walmart buildings... 😉 😛

There's a HUGE difference in a building with multiple supports (or even a 4 post lift) and a two post lift with cantilever forces.

 

[Howard]

If your afraid of simple concrete pads holding thousands of pounds above your head then you better stay out of walmart buildings... 😉 😛

Columns for buildings are typically 8" to 10" square with 5/16" to 3/8" thick walls (or more if there is loading other than simple steel truss/deck), resting on steel pads with concrete above/below. The loads are also not as high as they would be for a two-post lift. Furthermore, you don't have a professional engineer signing off on garage installs.

 

[SyndromeOCZ]

There's a HUGE difference in a building with multiple supports (or even a 4 post lift) and a two post lift with cantilever forces.

Yeah the emoticons were supposed to indicate sarcasm. A typical walmart super center has a nearly 10'x10'x2'6" spot footing under each steel pillar(which are accurate to Howard's description). Each one of these spot footing contain 2 rebar mattes of #5 or larger(5/8" diameter) on about a 9" center. Though it should be considered that Walmart building are some of the most over engineered structures I've worked on, they even make bridges look stupid when you consider what is actually going on with the whole process.

That being said you could cut a 3'x3' spot out of your garage floor and dig down a good 2 or 3 feet. Throw in a 2 mats of rebar and put rebar dowels into the existing concrete. Drop some all=thread bolts into it aligned correctly to how you will mount the lift. Bolt the lift to the all-thread after 30 days of cure time.

 

[phucheneh]

I'm assuming 'cantilever forces' refers to off-center weight balance pulling up on the studs/nuts in the floor.

I really don't think there's too much of this on a centered, symmetrical lift with a properly supported car. The asymmetrical designs I mentioned are a bit of a different story.

Still, though, even with the latter design, the front wheel is forward of the posts. I would think having the weight of the engine and trans primarily on the front arms would be enough that you'd be still have decently distributed weight.

But I'm all for overdoing the footings. Better safe than sorry.

 

[Gillbot]

I'm assuming 'cantilever forces' refers to off-center weight balance pulling up on the studs/nuts in the floor.

I really don't think there's too much of this on a centered, symmetrical lift with a properly supported car. The asymmetrical designs I mentioned are a bit of a different story.

Still, though, even with the latter design, the front wheel is forward of the posts. I would think having the weight of the engine and trans primarily on the front arms would be enough that you'd be still have decently distributed weight.

But I'm all for overdoing the footings. Better safe than sorry.

Ever see a car fall off a two post after pulling the motor or trans out? I have. Sometimes when you are under there pulling, pushing or prying you can put out more force than one would expect.

 

[sjwaste]

Gill, how wide a footer would you suggest is appropriate? I don't have a budget to redo my entire garage slab, but I would like to err on the side of caution, especially since an asymmetrical lift is probably what I'd like so that it's easier to use the parking space.

 

[skyking]

I installed a used two post over at the neighbor's; he had poured that bay of his shop at 6" thick because he knew he wanted a lift.
I think a 2' by 6' by 1' thick footing under each post would be more than sufficient, if properly reinforced with bar. You can saw cut out the old concrete and excavate out the 8" of dirt/gravel yourself.

 

[Gillbot]

I installed a used two post over at the neighbor's; he had poured that bay of his shop at 6" thick because he knew he wanted a lift.
I think a 2' by 6' by 1' thick footing under each post would be more than sufficient, if properly reinforced with bar. You can saw cut out the old concrete and excavate out the 8" of dirt/gravel yourself.

I think that's what most people leave out, the rebar. If nothing ties it to the existing concrete, it's just a small pad and i've seen them tear out.

As for a suggestion, I'm not a structural engineer so I don't know what would be sufficient. I'd suggest asking someone who does mechanical contracting for their opinion.

 

[phucheneh]

I'm just being curious here- how do you tie the rebar into the existing floor? Just drill horizonal holes in it? If so, what then attaches the rebar to said floor? Some kind of epoxy?

I guess I've always been under the impression that new concrete poured against old concrete will have some kind of decent adhesion (not saying I was right). Also, if the hole is cut at a 90* angle, you'd think the new 'block' of concrete would be stuck between the old due to the parallel surfaces butting up against one another...I'm guessing this is an issue of tensile vs compressive strength? i.e. it's not that hard to pry up and break an otherwise solid piece of concrete?

 

[SyndromeOCZ]

If you don't drill and epoxy the rebar into the existing concrete, then the new area may lift or drop. On most commercial jobs I've done you are required to have a 3rd party inspector present at all times when you are epoxying rebar. But yet when working on bridges I've placed thousands of bars with epoxy with no inspectors.

 

[Gillbot]

I'm just being curious here- how do you tie the rebar into the existing floor? Just drill horizonal holes in it? If so, what then attaches the rebar to said floor? Some kind of epoxy?

I guess I've always been under the impression that new concrete poured against old concrete will have some kind of decent adhesion (not saying I was right). Also, if the hole is cut at a 90* angle, you'd think the new 'block' of concrete would be stuck between the old due to the parallel surfaces butting up against one another...I'm guessing this is an issue of tensile vs compressive strength? i.e. it's not that hard to pry up and break an otherwise solid piece of concrete?

I'm not sure of the mechanics of it, but I sure as hell wouldn't want thousands of pounds supported over my head on two simple "blocks" of concrete with basic friction holding them in a hole. i would want them tied into the existing concrete in some way or at least have the pad large enough to be self supporting of the lift. Some people insist that flaring out the bottom will make the pad like an anchor and it won't pull through the floor but if the area under settles or anything, that much leverage I would think could readily break the existing floor at some point.

This alone is the reason I decided to skip a 2 post and opt to look for a 4 post even with the disadvantages of the 4 post. I would rather re-pour the entire floor or make the pad large enough that it could support the lift easily on it's own (like the entire length of the car). Since i'm not a structural engineer, I don't know what it would exactly require.

 

[leper84]

Remember that if you hide the connecting beam in the ceiling, you're assumably disabling the safety feature that keeps you from shoving the car into the roof. Most if not all lifts come with a safety bar across the top that stops the lift motor once the top of the car touches it.

I know at least the drive through two posts should have a cable going across the top bar set up on some pulleys. Car goes too high, stretches the cable, cable hooked up to the motor and creates an open to shut it off.

You should be able to remount all of that lower down as long as you get the cable length/tension down.

 

[sjwaste]

Well shit, this project has the potential to be a little beyond my budget. I'm personally not willing to risk safety on a DIY in an area where I'm not an expert, so I'd probably call someone in to do the concrete and it sounds like this would tack on another $500-1000.

I'm going to find a contractor in the area that installs lifts, maybe get a rec from one of the local garages. I'll try and get an all-in estimate and post back with what they think is necessary. I'm sure I can't afford it, but I won't know unless I ask 🙂

 

[exdeath]

Get a house with a 10" everywhere post tension raft slab and never worry about it again.

 

[JCH13]

Get a house with a 10" everywhere post tension raft slab and never worry about it again.

:awe:

 

[Gillbot]

Well shit, this project has the potential to be a little beyond my budget. I'm personally not willing to risk safety on a DIY in an area where I'm not an expert, so I'd probably call someone in to do the concrete and it sounds like this would tack on another $500-1000.

I'm going to find a contractor in the area that installs lifts, maybe get a rec from one of the local garages. I'll try and get an all-in estimate and post back with what they think is necessary. I'm sure I can't afford it, but I won't know unless I ask 🙂

Exactly why I decided to skip the 2 post in lieu of a 4. I was just too nervous of the slab and since a 4 can basically be free standing on it's own, that's a safer/better option for me.

 

[sjwaste]

Exactly why I decided to skip the 2 post in lieu of a 4. I was just too nervous of the slab and since a 4 can basically be free standing on it's own, that's a safer/better option for me.

Do all 4 posts lift under the wheels? That's my biggest hangup. I feel like every other project on our cars, I'm pulling the wheels off. A 4 post that could lift at other points would be a winner for me.

 

[funks]

Check out the ATLAS KWIKBAY - as soon as my townhouse is finished, will be buying one. You may want to go with a 2-post though if you have the ceiling height to do it (and can probably get proper concrete pads re-poured). But for us mere mortals, the following is great..

Reasons why I like it..

1) No problems with Concrete
2) Works reasonably well for both suspension, and exhaust, and engine work. Center section is open and you can use it to drop your clutch, or other type of work.
3) Price is relatively good
4) 110v (says it needs up to 30 amps though)
5) Fairly portable, can move it out of the way
6) Locks look beefy

http://www.youtube.com/watch?v=uUvC-H2p-SM

Here's the Bimmer Forums review..

http://www.bimmerfest.com/forums/showthread.php?t=616105

 

[franksta]

I've been doing TONS of reading about lifts. I designed my garage around having a 4-post in it later. Garage build thread.

Things to consider when deciding:
- Available space. It sounds like you've got enough room. Any manufacturer worth buying from will have the specifications on their website.

- Power requirements. Some pumps run on 120V and others are 240V and perhaps draw more than the 15A or 20A that is typically available in a garage.

- Concrete strength. Again, check the manufactures data for pertinent information. The 2-post I was looking at required a minimum thickness and strength, both thicker and stronger than what a typical garage would have.

- Lifting capacity. Heavy duty stuff usually costs more. Even the light duty stuff should be enough for your Supra. Check the rated capacity vs the vehicles you intend to lift now and in the future.

- Style. 2-post vs 4-post vs scissor vs portable vs something else is a pretty hot topic on some of the other forums I've read. I won't try to sell you either way but like anything else they all have benefits and drawbacks.

- Budget. Always a factor isn't it?


And to make sure the internet doesn't stop due to lack of pics:

My wife's car on her dad's 4-post. I think he traded a motor or transmission for it. And yes his garage is nearly identical to mine.

 

[Gillbot]

Do all 4 posts lift under the wheels? That's my biggest hangup. I feel like every other project on our cars, I'm pulling the wheels off. A 4 post that could lift at other points would be a winner for me.

I've never seen one that doesn't lift under the wheels, but many of them have extra jacks so you can lift the car off the platform and do work also.