Thoughts on this lift install? Good or bad?

[gh0st]

I bought my first house a few months ago and one of the big pluses was that it came with a lift installed. The lift is an ALM 7001a that has a big support to tie the two towers together. The previous owners installed it themselves and while they may have done everything correctly, I called a lift installation company out to inspect everything prior to the closing just to be sure. The guy said that the installation was more than adequate for the lift and that the lift itself was in fantastic shape. I always like to be super sure of things so I thought I'd ask you guys here since most of you seem to really know your stuff.

As for the installation what the previous owners told me is that since the existing floor pad wasn't perfectly level they decided to cut out sections and re-pour where the lift was going to sit. They cut the sections out only a few inches larger than the feet on the lift, dug down 12-18 inches and then dug out the sides underneath the existing pad a few inches so the pour looks like an upside-down T. Then they used 5k psi concrete.

So my question to you folks is: is that enough? The lift installation guy said it would be fine, but thought I'd run it by you as well.

 

[kd3pc]

not sure what you are hoping to gain, the "lift guy" is the expert and he has seen closeup your install....for us to speculate, seems irrelevant.

Is there some reason you do not value the inspection?

All that being said, with out pictures, speculation, on our part, is more like fortune telling...or remote viewing.

 

[gh0st]

not sure what you are hoping to gain, the "lift guy" is the expert and he has seen closeup your install....for us to speculate, seems irrelevant.

Is there some reason you do not value the inspection?

All that being said, with out pictures, speculation, on our part, is more like fortune telling...or remote viewing.

I value his opinion, but I like being reassured when I have a 3500lbs object above my head waiting to squash me. I uploaded pics shortly after I posted. You might not have seen them

 

[MG44]

My lift installers told me minimum 3 ft by 3 ft by 3ft to pour new concrete under posts.

 

[ltusler]

I would check the torque on the bolts, and some of them look like they are up too high.

 

[gh0st]

I would check the torque on the bolts, and some of them look like they are up too high.

The guy checked the torque on all the nuts and said they were good and they also went with slightly oversized bolts/nuts than most lifts which was a plus in his opinion

 

[C96]

I agree, the expert you had do the inspection should know if its worthy of safely operating as intended. The foundation below grade is the mystery here. All you have to go by is what the PO has told you. The only thing I can say and it’s hard to tell from the pictures, but the hold-down anchors look to be a little small in diameter. I would think ¾” diameter would be necessary, but I’m no expert. Also, a couple of them look to have pulled out a little judging from the amount of threads showing, possibly during the torque process.

I think it boils down to trusting the PO and the expert that made the inspection. As with anything, use caution and commonsense.

 

[Bob C]

IF, and only IF they let that concrete set 28 days before they drilled and lagged it. IF they did, then the repair is fine. Put it to use.

I say IF because of the excessive heights of the lag bolts. This would be a flag to me to have it redone due to wrong mix, weak mix, or lack of sufficient cure time before installation. IF concrete is of the same consistency and strength, it is unlikely the heights of the bolts would vary by more than a quarter to a half of an inch.

 

[Diesel Dan]

5K psi sounds like quickcrete bags to me.
The size of the aggregate in quickcrete is much smaller than what shows up in a concrete truck. Will it make a difference for this kind of application? I don't know.

As others have stated the bolts concern me with how far they stick out. You don't know if they are 6" or 12" bolts.

 

[coljar]

For me, the two things that would be a concern is: 1. Did they drill back in the existing concrete and install rebar? 2. How thick is the existing concrete? I suppose you could ask him about the rebar, but you can always drill 2 or 3 holes back a few feet and measure it if this is a concern of yours also.

 

[NCDave]

No disrespect to the guy who inspected the lift as he may be quite knowledgeable about the lift mechanism itself, but it appears he's a bit short on his structural engineering. The mechanics of it may be great, but that's not the whole story.

This install may work fine, as long as you don't put a lot of weight on it or get an off-center load going like a pickup truck. There's 2 considerations on the support of a 2 post lift - one is ability to support the weight, the other is the ability of the mount to resist overturning. Kinda like towing a trailer...it's one thing to pull it, another altogether to stop it.

Depending on the type soil you have in that location, a 12 by 12 (= 1 sq ft)may be adequate to keep it from sinking, but then it may not. In NC, our building codes "assume" a ground bearing of 2000 pounds per square foot (psf). If you put a 3500 lb vehicle on this lift, that's about what you would have on each post, as long as it was exactly in the center. But there are a lot of places in the state (and country) where the soil does not meet that requirement.

Overturning is a different matter. Besides supporting the load, the size of a pad determines it's resistance to overturning. As another commenter mentioned, a 3'x3'x1' pad is pretty much the minimum pad size for this type lift per the manufacturers. From the pictures the joints look like this one has wiggled a bit.

I'm pretty conservative on this topic (after having a vehicle fall on me a few years back) so if it were me, I'd move the lift, jack hammer out that 12x12 and put in a 3x3 (x12" thick) doweled with #4 rebar into the adjacent concrete floor, if the floor is thick enough. If it's not, go a little deeper with the 3x3, say 18" to get more overturning moment. Cut the excavated hole as cleanly as possible, no fill in. 5000 psi concrete (bag mix is fine, just follow the instructions on water content).

And use bigger bolts (sized by the hole in the lift base plates), preferably cast into the concrete (12" deep) as anchor bolts. If not, then Simpson StrongTie Concrete Screws, at least 6" long. No wedge or sleeve anchors (probably what you have there now). But that's just me. I hate hospitals, especially looking at the ceilings.....

Me: 6 yrs on-the-job structural engineering (in my younger days), licensed General Contractor 29 yrs, car nut for life.

 

[Bob C]

No disrespect to the guy who inspected the lift as he may be quite knowledgeable about the lift mechanism itself, but it appears he's a bit short on his structural engineering. The mechanics of it may be great, but that's not the whole story.

This install may work fine, as long as you don't put a lot of weight on it or get an off-center load going like a pickup truck. There's 2 considerations on the support of a 2 post lift - one is ability to support the weight, the other is the ability of the mount to resist overturning. Kinda like towing a trailer...it's one thing to pull it, another altogether to stop it.

Depending on the type soil you have in that location, a 12 by 12 (= 1 sq ft)may be adequate to keep it from sinking, but then it may not. In NC, our building codes "assume" a ground bearing of 2000 pounds per square foot (psf). If you put a 3500 lb vehicle on this lift, that's about what you would have on each post, as long as it was exactly in the center. But there are a lot of places in the state (and country) where the soil does not meet that requirement.

Overturning is a different matter. Besides supporting the load, the size of a pad determines it's resistance to overturning. As another commenter mentioned, a 3'x3'x1' pad is pretty much the minimum pad size for this type lift per the manufacturers. From the pictures the joints look like this one has wiggled a bit.

I'm pretty conservative on this topic (after having a vehicle fall on me a few years back) so if it were me, I'd move the lift, jack hammer out that 12x12 and put in a 3x3 (x12" thick) doweled with #4 rebar into the adjacent concrete floor, if the floor is thick enough. If it's not, go a little deeper with the 3x3, say 18" to get more overturning moment. Cut the excavated hole as cleanly as possible, no fill in. 5000 psi concrete (bag mix is fine, just follow the instructions on water content).

And use bigger bolts (sized by the hole in the lift base plates), preferably cast into the concrete (12" deep) as anchor bolts. If not, then Simpson StrongTie Concrete Screws, at least 6" long. No wedge or sleeve anchors (probably what you have there now). But that's just me. I hate hospitals, especially looking at the ceilings.....

Me: 6 yrs on-the-job structural engineering (in my younger days), licensed General Contractor 29 yrs, car nut for life.

I agree with most of what you stated. There is no need to size over 3/4 by 6" wedge anchors as the lift companies supply. Also I see no need to "cast" them in the concrete. ReBar? I'm ok either way. I would use fiber and key the slab under the existing concrete. I've installed lifts for thirty years and when installed properly, they work as designed. I understand your caution. I had a two post lift slice a ford pickup in half 29 years ago. (The reason that happened was due to me trusting what the customer told me). Companies like Rotary, Bend Pak, Challenger, etc have researched what anchors will keep the lift secure for its lifespan. There is always security in overkill, nothing wrong with that.

 

[gh0st]

Thank you all for the responses. This is exactly what I was looking for.

I'll keep an eye on the newly poured pads and use it as is for the next few months while I look into having the pads re-poured. Luckily the only thing that will be going up on this lift will be an old NA miata, so it wont really be stress tested in terms of weight

 

[cyamaha2007]

The rafter ties look like they have been moved to vault the ceiling. They look pretty high to me.

 

[Strouty]

My major concerns would be the fact that they used sakrete and that the anchors are very close to the edge of the pour.

I am not concerned about the sakrete itself, but more of how they mixed it. If they added too much water, it reduces the strength.

The anchors being so close to the edge is a big problem. If they are 6" anchors, you have lost almost half the strength they would normally have. Anchors in concrete grab at the bottom of the anchor and would pull on an area shaped like an upside down cone. At the edge of the slab, you lose a lot of that cone.

Will it work, probably, would it work forever, probably not, could you guess when it will fail, no way, when it does fail will it cause damage or injuries, that is the risk you take.

 

[gh0st]

The rafter ties look like they have been moved to vault the ceiling. They look pretty high to me.

The roof on that side of the garage has been re-done since those pictures were taken. An additional ridge beam and columns were put in place as per the town inspector

 

[marinusdees]

Any vehicle weighs more than 3500 lbs. Use it and don't worry, no load will "crash" down. It will slowly settle. It will not kill you. If you are worried, buy a life insurance policy and be sure it does not rider out a hoist crash.