2 or 4 posts hoists(lifts)

**Jim T.** · October 26, 2003, 03:27 PM

Re: 2 or 4 posts hoists(lifts)

Jack I believe my ceiling height is about the same as yours and I have two Autolifters M6 four point lifts in my garage. I have enough room left over for a 69 Triumph and 69 BSA Rocket motorcycles to be included and I could get one more behind a car that would have to be moved to back a Vette out. I back my Vettes in on the lifts and did not change my garage door except in how high it raises, its a Vette only garage, so the door height coming up is not a problem being to low for other higher roofline cars. The 96 and 85 are lower in the front than the 68 and 70, so if they were up, I could raise the height of the garage door opening. The garage door comes to within a couple inches of the 68 and 70's front fenders. I place a folded old blanket across the fenders and hood just in case something could happen inside the garage door opener mechanicals. Just cheap and easy insurance for me. If you want my actual garage measurements I can easliy get them for you.

**Chuck S.** · October 26, 2003, 10:52 PM

Re: 2 or 4 posts hoists(lifts)

Jack, based on a recent post here on two post lifts, your nominal 4" thick floor slab will preclude the installation of a two post lift.

I forget who posted this, but they work for an architectural firm; their structural guy recommends 8"(?) thick slab with both rebar and mesh reinforcement...not the typical home garage slab. It might be worth checking the archives.

The two post lifts offers better access, but some prefer the four post for storing vehicles or portability.

**Don G.** · October 26, 2003, 11:53 PM

Re: 2 or 4 posts hoists(lifts)

I installed a standard 7000# 4 post Backyard Buddy in a 9'4" ceiling height. The garage door is 7' high. I had a local garage door company raise the tracks and install new coil springs. No modification of the garage door opening was required and the door fully opens and goes within 9" of the ceiling. The track modification including parts and labor was $350. I back the car on the lift and everything clears just find with room for a second Corvette in the lower position. I am very happy with the result.

**Jack J.** · October 27, 2003, 10:22 AM

Re: 2 or 4 posts hoists(lifts)

Thanks for your responses. I was hoping to use a 2 posts lift to remove the body and store it while I work on the frame, engine, drive train and etc. I guess I was wondering if anyone had botherd to cut into their existing 4" floor a 1'-2' square then excavate and reinforce for a deeper "footing" for the base of the post. Feasible? Safe? And what would be the MINIMUM outside dimension between posts either purchased or modified without creating an obstacle for the other vehicle parked in the other half of the garage? Thanks again.

**Gary Chesnut** · October 27, 2003, 10:37 AM

Re: 2 or 4 posts hoists(lifts)

Jack,

Am on my 2nd 2 post lift. 2 post installations use a 5 inch by 3/4 inch wedge anchor bolt and required a 5 inch floor thickness as a minimum with good rebar structure recommended on 12 inch centers. First 2 post lift was installed on 5 inch slab over 10 years and had no problems.

Try to find the cross beam locations, check your home builder on concerete contractor for a layout of the slab beams. Good luck,

Gary#5895
....

**John H.** · October 27, 2003, 03:15 PM

Re: 2 or 4 posts hoists(lifts)

Here's the "high-lift" conversion for a sectional garage door; the top of the horizontal track sections are 9" from the (12') ceiling. It uses an extra top section (not visible from the outside) to maintain the correct lift/pull geometry for the opener.

Attached Files

DoorLift.JPG (59.6 KB, 5 views)

**Jack J.** · October 27, 2003, 06:05 PM

Re: 2 or 4 posts hoists(lifts)

John, I guess I was hoping to hear from someone who has installed a 2 posts lift in their "standard size" attached residential garage without the inside post becoming an obstacle nightmare. The idea of using, as others have, a 2 posts lift to remove, store, and replace the body is very appealing versus a 4 posts lift's limited functionality. With my garage's 19.5' width, a 2 posts lift might not be practical but certainly useful for restoration. I was wondering if anyone has used a 4 posts lift to raise the car, strap the body overhead and then lower the chasis or am I "daydreaming"? I just want to share a remark made to me by a great owner/boss(since departed)back in the mid-sixties. After I had come up with a "suggestion", He said, "Jack, it's better to think wrong then not think at all". So I just want to pursue all and any options before I commit my resources. Thanks again and I welcome any and all comments.

**Chuck S.** · October 27, 2003, 08:54 PM

Re: 2 or 4 posts hoists(lifts)

Jack, on your question about anyone cutting into their garage floor, I would say from my engineering background that, yes, it's definitely feasible. Safe? Yes, if the new foundation piers were properly sized and designed...have any structural/civil engineers as friends?

Expensive? You bet...we are talking pretty good-sized foundations because they won't have the rest of the floor to help react the overturning moment. A good design would probably pin the reinforcing steel of the foundation into the floor. Forget a 1' X 1' or 2' X 2' (maybe 2' X 2'if they are deep)...the base plate footprint of one leg I helped install was nearly 2' X 2'.

I'm wondering if you aren't overworking this two post lift idea as a way to remove and store your Corvette body. After many years of restoring a car, my body and dolly has changed garage bays several times. You will find that in a standard two car garage, a complete frame-off restoration will create extraordinary storage problems once all the pieces are apart.

You can forget about parking aother car in the garage; my experience is it can be done, but not much restoration work will happen. You have to do things like stand your frame on its side and lash it to the garage wall. You may have to free up a bedroom to store all your parts. A fixed two post lift with a body aboard may actually become an inflexible liability. As for cost, the lift expense will be considerably more than simply using the usual body lift techniques and a castered body dolly. JMHO.

**Kent K.** · October 27, 2003, 09:03 PM

Re: Garage floor slab recommendations

Further information received on floor structure since my last cautionary post indicates that, for a slab-on-grade condition, the concrete slab should be at least 6" thick with #4 rebar at 12" on center both directions. This prevents the slab from cracking under loads presented by 4 post lifts. With 2 post lifts, it is recommended the slab be 8" thick at the post locations with horizontal dimensions of 36" square depending upon your soil conditions and bearing capacity. The remaining slab may be 4" thick as usual. I havn't discussed structured (2 storey) floor slabs with our structural engineer as may be found up north. Whatever, it should be "Hell-for-stout" as one of my professors used to say.

Good Corvetting,
Kent #6201

**Jack J.** · October 28, 2003, 09:44 AM

Re: 2 or 4 posts hoists(lifts)

Thanks Chuck for your informative reply along with the others. I think that I have beat this "idea" to death and will move on to more practical matters such as building a body dolly of which I already have the wheels. I'm positive that I will be purchasing Noland's book soon so I can have some plans to work from as well as other valuable information regarding my "64". Thanks to all who took the time to reply.

**Gary Chesnut** · October 28, 2003, 10:16 AM

Re: 2 or 4 posts hoists(lifts)

You would need a minimum 10 1/2 foot ceiling, 11 foot is better, otherwise you can't stand up underneat the Corvette and the 2 post lift would have to have the cables and lines on the floor, not overhead. Most 2 posts with overhead lines and cables require a minimum of 12 foot clearance.

Have used a 2 post to remove and store a Corvette body while doing frame restoration and worked out good.

As pointed out in previous post if you cut slab, you would have to drill pier hole to rock or probably minimum of 6 foot with bell bottom (good civil foundation engineer would know exactly what's required for your soil, etc.).

Body dollies work well also. Good luck,

Gary #5895

**mike cobine** · October 28, 2003, 11:04 AM

Re: 2 or 4 posts hoists - other alternatives

Chuck is hitting the nail squarely on the head. While a lift is great, there are many alternatives to what you are trying to accomplish.

In one garage, I had a 12x6 inch wooden beam supported on 6x6 uprights the length of the garage (perpendicular to the cars). Ceiling was 10 to 14 ft slanted, and 12 ft at the beam. That had the chain hoist that lifted the body. The body was set on a dolly and placed anywhere in the garage as needed, or even outside when it wasn't needed.

Another was a 15 ft ceiling and had inline 24 inch triangulated wire beams with a pair of trolleys, a beam between, and a center trolley with hoist on it. Great flexiblity and hated to give that up.

The lift is good primarily for working under a car and recently for storing one car over the other. But as many can tell you, HAVE NO LEAKS from the one above. If you are in earthquake country, you have a potential for not one, but two disasters. And a lift is a big piece of equipment that gets in the way in a small garage.

A pit on the other hand provides the under car access, a storage area for engines and other parts, and does not take up floor space if you have a proper cover. My Nationwide home agent says that there is no insurance problem with a pit and has several clients with them. Yours may vary.

A pit will not fall on you, but a cheap or improperly installed lift will.

Figure to do it well, you need one car space for the body, one car space for the chassis, and at least one car space to spread parts. That doesn't fit the philosophy of crowding in next to the wife's car.

It all boils down to one thing - plan your garage in advance.

**Jack J.** · October 28, 2003, 04:10 PM

Re: 2 or 4 posts hoists - other alternatives

To all who responded, I was trying to justify the premature purchase of a lift as the ultimate tool in the restoration process. Good idea but not necessary and, with the dimensional restraints of my standard attached garage, obviously not practical. Again, back to plan A, Lift Body-Lower Onto Dolly. Thanks again for all the knowledgeable input. The 64 has been SITTING for 26 years so I guess I shouldn't rush into things.

2 or 4 posts hoists(lifts)

2 or 4 posts hoists(lifts)

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Debug Information