Drilling and anchoring 2 post lifts

[3x9RT/SE]

Another question I have as I am coming closer to pulling the trigger on one is,what I have basically learned is they say you have to have minimun of 4'' 3000 psi.Because of my radiant floor heat in the concrete,I chose to go 6'' for the whole floor(retain the heat longer from the larger mass of concrete),and knowing that I would def be doing a 2 post lift,the area where the bases would be I dug it extra deep,so it's in the neighborhhod of 8,9'' or so,maybe even more.And I got measurements from a lift company who is since out of business to divert tubing away from that area.
My question is,are the 5'' x 3/4'' quick bolts standard for these types of lifts??And as the bolt when hit in is really not going deeper than 4'' or so,so how far do you drill?Keep going so you know for sure they won't bottom out?If your floor is only 4'',you would just about be going thru it.

 

[3x9RT/SE]

Also,tighten to certain torque,or tight as you can???I am in the HVAC field,and see first hand what 3/8'' and 1/2'' drop-ins or as we call "shields" can hold,ductwork,units,pipes,etc,from the ceiling!!!!Never mind a 3/4"thunder stud", "quick bolt".

 

[Vicious_Cycle]

The torque spec for my anchors was 150 ft-lbs. This spec was consistently stated several times throughout the documentation for my new lift. It caused me a great deal of grief... that number was not attainable; the anchors pulled out of the concrete before I got to 150. (when there is a socket over the nut and the anchor, you don't necessarily see the anchors pulling out!)

After making a mess, I spoke with an installer who said he never attempts to torque the anchors to the spec- he snugs them down real good with an impact until they are tight, then stops. They have to be checked periodically to ensure they haven't loosened with use.

 

[svtride]

When installing my Rotary 2-post (i did it my myself), I followed the instructions to the letter. I believe I drilled the 3/4" holes to the appropriate depth as stated for the Hilti fasteners supplied with the hoist. I too have in floor heat and had the concrete company make 4x4' pads under the posts 10" thick and not route any pex tubing in that area. What I made sure was to remove any and all drill dust after I met the required depth. It took several attempts to get all the dust out. Make sure the hole is clear of all debris. I was able to easily attain the 150 lb/ft torque as Rotary stated and still be well within the max stud stick-out height specified above the slab.

More than 2 years after the installation, I just recently re-torqued the nuts on those fasteners and was surprised that I was able to get up to 1 revolution on 1 of the 10 nuts before it hit 150ft/lbs. All the others took maybe 45-180 degrees to attain the 150ft/lbs. Stud stick out above the slab was still well within specified limits. I plan to recheck the torque every couple of years. Good Luck with your install.

 

[Perryk]

I have 4'x4'x8" thick footings under my posts. I scrapped the 5.5" anchors that were included with the lift and went with some 7.5" anchors. I drilled all the way through my 8" footings, hammered the anchor in leaving about 3/4" above the baseplate and torqued them down.

To get the dust out, I had a buddy holding the shop vac next to the bit while I drilled.

 

[Ign]

It's not uncommon to intentionally drill all the way thru the slab so that if you ever want to you can remove the equipment and pound the anchors down into the dirt, then fill the hole.

I don't recall if there was a torque spec stated on my Bendpak, but then again I chose to use epoxy rather than the mechanical "wings" on the anchors (which I removed). I snugged 'em until I felt it was sufficient, using a standard 1/2" drive ratchet.

General concrete has enough inconsistencies I don't see how you could ever hope to achieve a specific torque spec. I view it like snugging a castle-ated nut on a tie rod: get it sufficiently tight.

Don't worry about bottoming the anchor during install, provided it's deep enough. It will pull up as soon as you begin snugging it.

 

[mooman]

We install pallet rack in large distribution centers all over the country (hundreds of thousands of anchors each year). As a rule, we always drill through the concrete, in case the rack has to be removed, it's easier to pound the anchor down into the floor after the rack is removed.
Also, NEVER use an impact to tighten the anchors. They are not meant to be shocked by an impact wrench after they have been embedded into the concrete. We use both Hilti and Simpson anchors, both caution against the use of impacts.

 

[KCarGuy]

In the Lab at Work, They had to install a "Shake Table". Which is a very large Hydraulic Table that Weights several Tons. Its designed to test every style of delivery for packages.
It takes quite a beating, it can be on for 48 hours straight.
it was mounted using 12" SS threaded Rods, sunk into holes drilled into the concrete.
To set and hold the rods in place, a 2 piece Epoxy compound that comes in "Dual Tube" system called "Quake Proof Epoxy".
You squeese the Handle, It delivers the exact ratio of "A" and "B" to the tip. Squirt some down in the hole, then on 3/4 of the threaded rod and sink the rod (Make sure that it it straight). The Epoxy heats up and within a couple hours is hard, although waiting 24 hours is recommended. (do not get any on the top portion of the threads).
The "Shake Table" has been running 5 days a week for 12 years without any issues.
And I am sure it stresses the bolts way more than a Lift could.

 

[wssix99]

The slab thickness is key because only one half of the slab takes the twisting force of the lift attached to the concrete. (Depending on which way the column is twisting, either the top or the bottom is in compression - which is the force that the concrete will withstand.) With 6" of concrete, your slab should be around 50% stronger than a 4" slab. 3000 psi concrete is a common strength.

If you get deeper anchors to contact more of your 6" slab, they will resist pulling out more and you'll have an easier time developing the proper torque. (Just be sure the strength of the bolts you use meets the spec of the lift or matches what was provided.)

Torque is important - so you'll want to see what your fasteners or lift instructions say. When you torque a bolt, it physically stretches the bolt along its length and develops a greater friction force on the threads. (This force keeps the bolt from twisting back out.) Having the bolts properly torqued also gives you assurance that they won't pull out as the lift takes on a load. (If the anchors pull out due to the normal stretch of the bolt, then they will probably pull out as the lift takes on large loads.)

 

[bobadame]

I finally installed my Western lift this weekend. The installation manual called for 75 foot pounds on the 3/4" studs.

 

[Jack Olsen]

Why isn't it more common to add an epoxy adhesive to these bolts as a kind of insurance. For a lift, I can't see the downside. But maybe there's a reason?

 

[mikeceli]

Why isn't it more common to add an epoxy adhesive to these bolts as a kind of insurance. For a lift, I can't see the downside. But maybe there's a reason?

I was wondering the same thing.

 

[3x9RT/SE]

The slab thickness is key because only one half of the slab takes the twisting force of the lift attached to the concrete. (Depending on which way the column is twisting, either the top or the bottom is in compression - which is the force that the concrete will withstand.) With 6" of concrete, your slab should be around 50% stronger than a 4" slab. 3000 psi concrete is a common strength.

If you get deeper anchors to contact more of your 6" slab, they will resist pulling out more and you'll have an easier time developing the proper torque. (Just be sure the strength of the bolts you use meets the spec of the lift or matches what was provided.)

Torque is important - so you'll want to see what your fasteners or lift instructions say. When you torque a bolt, it physically stretches the bolt along its length and develops a greater friction force on the threads. (This force keeps the bolt from twisting back out.) Having the bolts properly torqued also gives you assurance that they won't pull out as the lift takes on a load. (If the anchors pull out due to the normal stretch of the bolt, then they will probably pull out as the lift takes on large loads.)

Wow!!!! from 4'' to 6'',increases strength that much?????Was I a nervous nelly,by going to 8-9'' where my lifts its,I mean going to!!!!!I plan on getting the longer 7'' bolts to!!!!!

 

[sberry]

Also as was pointed out,,, no impacting of anchor bolts.

 

[3x9RT/SE]

Also as was pointed out,,, no impacting of anchor bolts.

Absolutely not!!!!!

 

[cwlo]

Using epoxy with anchor bolts might be going into uncharted territory. I suppose its possible for the two systems to interfere with each other. For example, what if the cured epoxy prevents the anchor bolt from securing properly into the concrete. Or perhaps the uncured epoxy could allow the bolt to spin and not embed properly. Just thinking out loud.

Chris

 

[mad57]

Why isn't it more common to add an epoxy adhesive to these bolts as a kind of insurance. For a lift, I can't see the downside. But maybe there's a reason?

Guessing here maybe if you put it in and right away tightened to spec other wise wouldnt it not expand like it should if left to harden before you torque it? Also if you wanted to remove the bolt you could not tap it down.

 

[wssix99]

Wow!!!! from 4'' to 6'',increases strength that much?????Was I a nervous nelly,by going to 8-9'' where my lifts its,I mean going to!!!!!I plan on getting the longer 7'' bolts to!!!!!

Well, there are several forces involved... On a 2 post lift - You can think of the lift post and the slab forming an upside down "T" if you look at it from the side. Looking at the "T" from the side, the post wants to twist left and right as the lift takes on a load. (There is less twisting if the center of gravity of the load is centered along the middle of the column. The further the load's center of gravity is out left or right, the more twisting and more strain there will be on the slab and anchor bolts.) At the base of the post twists:
- The slab acts as a beam and bends. The thicker the slab, the more resistance it has to this bending force. This is where the 6" slab will give you 50% more strength over the 4" slab.
- The post will pivot on its center at the slab and will press on one side of the plate and pull up on the other side of the plate. The anchor bolts don't do much on the pushing side but really earn their money on the pulling side. This is where the 6" contact in the slab (with longer bolts) will give you more resistance to a pull-out over shorter bolts.

The same forces are involved as the lift racks side-to-side between the posts, but the forces are much lower.

The deeper footing may not do as much for you, depending on how far it extends beyond the base plate of the lift. (The further it extends, the more it will help resist the bending force on the slab - the slab is really what is doing the work.) Depending on how the slab is constructed and how well the dirt under the slab is compacted, the deeper footing may help you withstand more settlement of the area the lift is in.


I'm not sure why we don't see epoxy anchors more, but in commercial construction, they are "the thing" and are very common.

 

[3x9RT/SE]

My entire garage floor was graded to 6'' depth,but the area that the 2 post lift were to be sitting,we took the bobcat,so a buckets width and basically scooped out a path clean accross from one side to the other.So it's not like I made a 2'x2' box but rather a whole swath deeper down to abaout 8,or 9'' thick now,who knows,might be deeper than that,we did'nt measure.I plan on getting the longer 7'' anchor bolts to use on whatever lift I go with.

 

[tatra]

i have used an impact on hundreds of anchours , find that it " seats " faster and no failures to date.......in all fairness this hasn't been on lifts and or such, mostly staionary equipment , tables and angle iron shelves for concrete steps attached to the buildings foundation.............usually burp the gun and finish off by hand...........

 

[Challenger lifts]

We recommend a screw pad height between 3 7/8” to 7 1/8”. No anchors should be installed within 8 inches of any crack, edge, or expansion joint. If these conditions cannot be met, a pad may be poured to accommodate a lift.

 

[Shadowdog500]

Mohawk is the only Company that i think gives detailed slab and install requirements, including slab cross section drawings. I think people should use these instructions for any lift. The anchors on my Mohawk lift were torqued to 85 ft.lb. I was told to retorque them at three months and one year.

Here are the instructions.
http://www.mohawklifts.com/library/manuals/Slab_Require_Recommend_11_07.pdf

Chris

 

[snorky18]

Why isn't it more common to add an epoxy adhesive to these bolts as a kind of insurance. For a lift, I can't see the downside. But maybe there's a reason?

I can think of 2 reasons I would shy away from that:
1. Adding any kind of liquid would lubricate the threads, which would invalidate the specified torque you should achive, since the lubrication would affect the torque required to achive a certain bolt tension.
2. What if you ever need to remove them?

That being said, I would consider using a small amount of blue threadlocker.

 

[snorky18]

Mohawk is the only Company that i think gives detailed slab and install requirements, including slab cross section drawings. I think people should use these instructions for any lift. The anchors on my Mohawk lift were torqued to 85 ft.lb. I was told to retorque them at three months and one year.

Here are the instructions.
http://www.mohawklifts.com/library/manuals/Slab_Require_Recommend_11_07.pdf

Chris

From the Mohawk instructions:
"NEW SLABS MUST BE 12" THICK MINIMUM !!"


Doesn't this seem a bit.... excessive? Does Mohawk sell concrete as well?

 

[swharris]

We recommend a screw pad height between 3 7/8” to 7 1/8”. No anchors should be installed within 8 inches of any crack, edge, or expansion joint. If these conditions cannot be met, a pad may be poured to accommodate a lift.

Good to see a rep from Challenger here. Been seriously looking at your asymmetrical two posts. I would really like to have the two post in ground, but it's a bit out of my price range. Can you give your impressions of let's say the CLFP9 and the EV1020? This will be for a home shop lifting light duty cars and trucks.

Thanks.

 

[Challenger lifts]

Good to see a rep from Challenger here. Been seriously looking at your asymmetrical two posts. I would really like to have the two post in ground, but it's a bit out of my price range. Can you give your impressions of let's say the CLFP9 and the EV1020? This will be for a home shop lifting light duty cars and trucks.

Thanks.

CLFP9 is a nice lift for the money – fits in short ceiling spaces and would work fine for light duty cars/trucks. It’s meant to be used as a symmetrical lift (vehicle’s center of gravity positioned between the columns) so with some vehicles you may run into tight space between an open door a lift post. If ceiling height is not an issue let us know at [email protected] and we’ll recommend a better solution. Inground (EV1020) eliminates the space and door clearance issue, but as you mention, will cost you more.

 

[swharris]

If ceiling height is not an issue let us know at [email protected] and we’ll recommend a better solution. Inground (EV1020) eliminates the space and door clearance issue, but as you mention, will cost you more.

This is new construction and I'll have about 15' at the peak. I will be lifting fairly tall vehicles(VW busses). Will I need extensions or can the cross over's be put on the floor?

 

[mrb]

i know this is how its done, but the thought of drop in anchor bolts (red heads) for a 2 post lift scares the **** out of me. If I were ever to install a lift, it would be sitting on footings with embedded zig-zag anchor bolts.

 

[wssix99]

i know this is how its done, but the thought of drop in anchor bolts (red heads) for a 2 post lift scares the **** out of me. If I were ever to install a lift, it would be sitting on footings with embedded zig-zag anchor bolts.

Think about what your garage floor supports without a lift... The entire weight of the car sits on four very small contact patches where the tires touch the concrete. When the car is on a lift, all the weight is on two large contact patches (created by the steel plates at the bottom of the lift legs) so the stress on the concrete slab ends up being just about the same as when the car is parked on the slab. No footing necessary!

The real stress on the slab comes when you put an unbalanced load on a two post lift. That "twists" the slab and is where the bolts do their work. If the load is perfectly balanced, the bolts aren't (theoretically) stressed at all. The better the bolt holes are drilled, the better contact the bolts have with the slab, and the stronger the bolts are - the more protection you have against unbalanced loads.

 

[mrb]

Think about what your garage floor supports without a lift... The entire weight of the car sits on four very small contact patches where the tires touch the concrete. When the car is on a lift, all the weight is on two large contact patches (created by the steel plates at the bottom of the lift legs) so the stress on the concrete slab ends up being just about the same as when the car is parked on the slab. No footing necessary!

The real stress on the slab comes when you put an unbalanced load on a two post lift. That "twists" the slab and is where the bolts do their work. If the load is perfectly balanced, the bolts aren't (theoretically) stressed at all. The better the bolt holes are drilled, the better contact the bolts have with the slab, and the stronger the bolts are - the more protection you have against unbalanced loads.

im not talking about the compressive force from the weight on the concrete, im taking about the forces on the bolts from all different directions. couple thousand pounds of car 6 feet in the air is going to put a tremendous load on those bolts in an earthquake (im in so cal)

 

[Shadowdog500]

From the Mohawk instructions:
"NEW SLABS MUST BE 12" THICK MINIMUM !!"


Doesn't this seem a bit.... excessive? Does Mohawk sell concrete as well?

The slab requirements shown are only 4.5" for my System-1.

The 12" thickness is for when you need to cut out and replacing the concrete directly around the columns on a concrete floor that is not sufficient for a lift.. They even show you the proper way to attach these new sections into the existing slab.

I seriously doubt that anybody would read that and think that the 12" thickness requirement were for an entire floor.

Chris

 

[59 wagon man]

just curious if the lift was going to collapse do you really think that epoxy or not the anchors won't rip out? think of the leverage that an 8' high column would exert on the anchor. the anchors basically just hold the columns from spreading . also i was told by the lift instaler i bought mine from to drill completely thru the slab. had a grand 9000 lb 2 post lift before my 4 post and it was never bolted down

 

[59 wagon man]

just curious if the lift was going to collapse do you really think that epoxy or the anchors won't rip out? think of the leverage that an 8' high column would exert on the anchor. the anchors basically just hold the columns from spreading . also i was told by the lift instaler i bought mine from to drill completely thru the slab. had a grand 9000 lb 2 post lift before my 4 post and it was never bolted down

 

[wssix99]

im not talking about the compressive force from the weight on the concrete, im taking about the forces on the bolts from all different directions. couple thousand pounds of car 6 feet in the air is going to put a tremendous load on those bolts in an earthquake (im in so cal)

Ah - The bolt sizing and specs from the manufacturer would be such to counteract any normal tipping force from the lift. If that force is magnified by an earthquake, the lift welds could brake or the concrete slab could crack from the bending, but a footing wouldn't help this much unless it was very large and tied in to the larger slab.

I wonder if any manufacturer rates their to post lifts for earthquakes? (I'd expect this wouldn't be a problem at all for 4 posters.)

 

[3x9RT/SE]

just curious if the lift was going to collapse do you really think that epoxy or the anchors won't rip out? think of the leverage that an 8' high column would exert on the anchor. the anchors basically just hold the columns from spreading . also i was told by the lift instaler i bought mine from to drill completely thru the slab. had a grand 9000 lb 2 post lift before my 4 post and it was never bolted down

WHAT ?????? Never bolted down????

 

[nehog]

I wonder how many properly documented cases there are of mounting/bolt failures for two post lifts? I, myself, am not aware of any, through I'm aware of some lift failures (mostly cheap, overloaded, imported lifts), but not mounting failures.

BTW, my Rotary lift came with all hardware and very detailed instructions (like described for Mohawk lifts above) which I simply followed exactly.

 

[Vicegrip]

I wonder how many properly documented cases there are of mounting/bolt failures for two post lifts? I, myself, am not aware of any, through I'm aware of some lift failures (mostly cheap, overloaded, imported lifts), but not mounting failures.

BTW, my Rotary lift came with all hardware and very detailed instructions (like described for Mohawk lifts above) which I simply followed exactly.

I just finished installing a rotary 2 post in a com shop. Very detailed instructions. I only install to the instruction to the letter. I don't need the legal issues of going "off label". I drill through as well. In addition to making them go away when you remove the equipment if you damage a wedge anchor during install you can drive it though and install another one.

I used to do a lot of work in health clubs that had very large washing machines. They generated a lot of vibration and power that seemed to be just right for pulling bolts out of slabs. I used wedge anchors along with epoxy in well cleaned dust free holes to counter this. It worked very well. Never had a pullout or non torque on an epoxied anchor in a proper hole. The epoxy did not change install as to torque as the thread portion of the anchor was not wetted. Non vibration conditions "dry" installed wedge anchors work well in good concrete when installed correctly. I would think that a 2 post lift is a non vibration condition.

 

[brownbagg]

properly the reason you dont see more epoxy bolts are: they are easy to put in wrong, hole too big, hole not cleaned out, hole has moisture, it not going hole. Out of ten bolts installed, one will fail. so the other method is the fail safe due to bad installment procedures.

 

[Vicegrip]

Just to be clear on my post above I install per dry bolt methods with the addition of epoxy in high vibration conditions. The bolt would have been a good bolt dry.

There are epoxy based bolting systems that are approved by some of the life makers such as Rotary for example. 9 of 10 go well one hole is egged out after drilling next to some rebar and the wedge anchor does not torque to spec. Hammer it through and install an approved use epoxy bolt. This in not a glued in wedge bolt. It is an anchor designed for the method.

 

[ponchopower]

properly the reason you dont see more epoxy bolts are: they are easy to put in wrong, hole too big, hole not cleaned out, hole has moisture, it not going hole. Out of ten bolts installed, one will fail. so the other method is the fail safe due to bad installment procedures.

I would totally disagree with this post, and question the "out of ten bolts installed, one will fail" statement strongly. Frankly, there are too many misconceptions about the epoxy based anchors and this statement reflects those.

Many epoxy compounds can be used in holes with water in them in commercial areas. Holes drilled too large or not cleaned out will have even a greater negative effect on wedge anchors than epoxy. Wedge anchors being "fail safe" couldn't be further from the truth.

What epoxy based solutions can be is more expensive, and a little less convenient in that once you open a tube of the two-part epoxy you don't have long to use it. No capping it for later. And the epoxy isn't cheap. And if you use any tools with it like a scraper, you'd better plan on throwing them away when you're done. But, they are stronger - period.