Two post lift opinions

[rockfla]

Well, here goes...gas now thrown on the fire


Dean333
I am an industrial fastener sales/VP, I started in the tool and fastener business in 1984 selling power tools, accessories and concrete anchors and cutting tools. I have been in this business for at least 35 years selling to every type of concrete, general, mechanical, HVAC, Marine contractor, ship fitter, fabricator, machinist, loggers/timber/land clearing and welding contractor imaginable. I have been to several concrete anchor seminars, classes and sales classes etc etc over the years for several manufacturer engineers of anchors, concrete screws, powder actuated pins, loads, clips, diamond blades, core bore bits, more than you can shake a stick at. I know the lift manufactures say 6" of concrete min required etc etc and many here have posted about making concrete foundations 12" deep etc, etc. My concrete floor is 5". My two post lift is a 9000lb lift anchored with no less than 6 (if not 8, I'd have to look again) wedge anchors per post and I am another 1-1/8 deeper than you will be SO I am a little bit higher in strength rating (i figured close to maybe 8000), which is what the majority of installers use. When properly installing a 3/4 wedge anchor, a minimum set depth is 3-3/8" MINIMUM (and in actuality, you're only as strong as your concrete) so, IF you used 3-3/4" embedment in 2000 psi concrete that anchor will have a tensile strength of 7120lbs and slightly more since you would be going another 3/8 of an inch deeper. NOW remember that is with ONE anchor, your lift will be anchored by at least 6 anchors so you can spread that load over 6 anchor points, THEN, keep in mind your spreading the load of your lift between TWO Post SO that load is being supported by a of 12 anchoring points of 7120lb.....The concrete at the maximum is only rated at 2000psi.....Maybe more, depending on your areas build requirements??? IF it's 4000lb concrete you can jump your tensile to 14,740Lbs of tensile strength. I used 4-1/2 embedment depth, plus the thickness of the base of my post, plus nut, washer AND the pull to tighten factor for my anchors. I know I will never have a vehicle close to 9000Lbs on my lift NOR would I put that much on it anyway. I am a firm believer OF 75% of whatever I am using is rated for....WHY push it? The most I figure I will ever have is 5000Lbs for what I do or for my needs. I have lifted my 39 Mercury 4 door (at the 4 "X" brace points of the frame), my wife's 2018 Lincoln MKX and parents 2011 Lincoln MKX, Jeeps, Honda's, my 2017 F-150 ALL with NO hesitation of my safety NOR any indication of any problems or safety concerns!!! I deal with this issue and an council/help contractors every single day solve anchoring issues for A/C units, safety lines for workers, light poles, guard rails, scaffolds, you name it where safety and lives depend on proper installation AND believe me, IF i didn't have confidence in what I posted MY keester would NOT be under that lift!! NOR would I be in this business for as long as I have been or have the trust and reputation of my customer most for the past 25 years, a few for my full 35+ years.



NOW, I wanted to use what is called a"Drop-In" anchor as opposed to a wedge anchor for my lift 1) because its a threaded wedge insert style anchor and you use a regular hex head cap screw to anchor down the lift and 2) because IF you moved or needed to move the lift you just unbolt it and move it and you don't have threaded studs sticking up out of the floor that you have to cut off if you move it. 3) With the right length bolt you have a constant force pushing the wedge of the insert down and putting moe anchoring force to the insert!!! Those are only 3-3/16" long thus 3-3/16 minimum embedment BUT they give you a 8280lb of tinsile strength, minimum in 2000lb concrete BUT the installer I used did not want to use them SO I went with the wedge anchors....which also tells you what faith I have in what I print!!!


Now IF you were pouring or starting from scratch, I would say pour 6" of concrete OR yea, bite the bullet and make your 12" foundation with rebar and anchor bolts and all that added "insurance" BUT the reality is....it is a safety factor X3 endevor, which I am not saying is wrong or bad.....but what I have printed here ALSO has a "safety" factor built in as well SO.....If it were me and I had the room at my duplex for a lift, I would not hesitate to put it in.


JMO and For the "What its worth" department.


Rockfla