Install Prep Myths About Automotive Two Post Lifts, Busted by a Des Moines Metro Site Survey

An EV specialty shop in the Des Moines metro brought us in last year to survey two bays before they ordered a pair of automotive two post lifts for alignment and undercarriage work. The owner had read a dozen blog posts and arrived at the walkthrough with a list of confident assumptions. Almost every one of them was wrong — not because he wasn’t sharp, but because the internet is full of install advice written by people who have never held an anchor gun. We walked the slab, pulled out a tape and a rotary hammer, and by the end of the visit his plan had changed in four significant ways. Here are the myths we bust most often on site surveys, and what we actually measure instead.

Myth: “My Slab Is New, So the Concrete Is Fine”

New concrete is not automatically good concrete for anchoring a lift. What matters is thickness, compressive strength, cure time, and reinforcement — and a brand-new pour can fail on at least two of those. Most manufacturers want a minimum of four inches of 3,000 PSI concrete for a 10,000 lb unit, more for 12,000 lb and up, and they want it fully cured. Anchoring into a slab poured three weeks ago is a good way to spall the concrete around your bolt holes. We’ve seen it.

The EV shop’s building was two years old, which sounded reassuring. When we drilled a test hole we found just under four inches over vapor barrier, with the wire mesh sitting too high. That’s a common story in metal buildings where the interior slab was poured to a spec written for parked cars, not for point loads from a column. The fix wasn’t complicated — we cut out two pads, dug down, and poured proper footings at 3,500 PSI, roughly four feet square and eight inches deep at each column location. One day of work. The alternative was two lift columns slowly working loose under alignment loads, which is how a bay becomes a lawsuit. When we survey for automotive two post lifts, the drill comes out before anything else, and the customer gets a real number instead of a guess.

Myth: “Ceiling Height Is Just the Peak of the Roof”

Everyone measures to the highest point and stops. The number that actually governs your install is the lowest obstruction anywhere in the swing and rise envelope: the overhead door track, the door opener, a light fixture, a fire sprinkler head, a truss web, a heater, a conduit run. In the Des Moines metro shop, the peak was over sixteen feet — plenty. The overhead door track ran at eleven feet ten inches, directly across where column one wanted to go.

That single measurement changes your product choice. A clear-floor overhead unit needs its top beam to clear both the vehicle at full rise and every obstruction above it, and the beam itself typically sits between twelve and fourteen feet depending on the model. When you can’t get that, a baseplate unit is the answer — cables and hose route through a low floor channel instead of overhead. We had a lead from a shop with a hard 139-inch maximum height, and that number alone eliminated every overhead model on his list. It wasn’t a downgrade; it was the correct configuration for his building. Before you shop automotive two post lifts, walk your bay with a tape and write down every obstruction height, including where the door panel sits when it’s rolled up. That panel stack is the one people forget, and it’s usually the lowest thing in the bay.

Myth: “Bay Width Is the Only Layout Constraint”

Width matters, but depth and adjacency matter more than most people expect. A 10,000 lb two post column footprint is roughly twelve feet between columns, and you need swing room for the arms plus walking room outside the columns plus door-open clearance for the vehicle. Then you need to think about what’s next to it. One customer we quoted had a loft on the left side of his shop and a wall on the right — plenty of width on paper, but the loft cut his usable height on one side, so the lift had to shift off center.

For alignment work specifically, layout gets stricter. You need line of sight for targets, room to walk both sides of the vehicle with a wheel clamp in hand, and a level working plane. In the EV shop’s case we also had to plan for charging cable management and a battery service cart that needed to roll under the raised vehicle — which reinforced the clear-floor preference and forced a real conversation about where the compressor lines ran. Take twenty minutes and chalk the full footprint on your floor, then walk it with a wheel and a floor jack. If you bump something, you’ll bump it every day for the next fifteen years. This is the cheapest, most useful thing you can do before ordering. Related: our guide to planning bay layout for a lift install.

Myth: “Power Is Just an Outlet”

Power units on automotive two post lifts commonly come in 208-230V single phase or three phase configurations, and they are not interchangeable after the fact without buying a new power unit. That’s a several-hundred-dollar mistake made at the order screen. Confirm what your panel actually delivers, what amperage you have available, and whether the circuit is dedicated. A shared circuit that also runs a compressor will nuisance-trip and shorten motor life.

The EV shop had three phase available — most EV service outfits do, because their chargers demand it — but the panel was on the far wall and running conduit was a separate contractor and a separate two-week lead time. We flagged it during the survey so the electrical was done before the freight truck arrived. That sequencing is the whole point of a site survey. We’ve had installs where the lift sat on a pallet for three weeks because nobody ordered the disconnect. Also plan where the power unit lives: it mounts to a column, and the disconnect should be within reach but not where an arm sweeps it. Add a drip pan under the reservoir if you’re doing fluid work in that bay. Small details, but they’re the ones that determine whether the install day goes smoothly or turns into three trips.

Myth: “Any Contractor Can Anchor It”

Technically anybody with a hammer drill can set anchors. Doing it right means torquing to the manufacturer’s spec, verifying anchor embedment depth, checking column plumb in two planes, shimming correctly, setting the safety locks so both columns engage simultaneously, bleeding the hydraulics fully, and cycling the unit under load. Then it means documenting it, because ALI-certified equipment and your insurance carrier both care about a proper commissioning record.

The mistake we correct most often is columns that were set plumb to the floor rather than plumb to true vertical. If the slab has a drainage slope — and most shop floors do, intentionally — a column set square to the slope leans. Under load, that lean puts the carriage rollers into a bind and wears one side of the column. We’ve replaced slider blocks on units less than three years old for exactly this reason. Shims exist for a reason and they’re not optional. The same goes for cable equalization: if the two carriages aren’t synchronized within spec, the lift will rack a vehicle slightly, which for alignment work is a direct accuracy problem. When we install automotive two post lifts we cycle them at least a dozen times under load before we call it done, and we hand over the torque log. See also our article on annual lift inspection requirements.

Myth: “Site Surveys Are Just a Sales Visit”

We get this one a lot, usually from people who’ve been burned by a vendor who showed up, quoted high, and left. A real survey produces a document: slab thickness at each column location, obstruction heights, available power, proposed footprint with dimensions, any concrete remediation needed, and a freight and rigging plan for getting a 2,000 lb column through your door. If you don’t get that, you got a sales visit.

For the Des Moines metro EV shop, the survey changed the order in four ways: baseplate instead of overhead because of the door track, two footing cut-outs instead of direct anchoring, a three phase power unit with new conduit, and low-profile arm kits because half their vehicle mix sits low with heavy battery packs and tight rocker clearance. If they’d ordered off a website in March, three of those four would have been wrong and the install would have stalled. The survey cost them an afternoon. It’s also worth saying that survey findings sometimes push a customer toward a different category entirely — a couple of times a year we tell somebody a four post or a mid-rise scissor is the better answer for their building. We’d rather sell you the right thing once.

What We Actually Check, in Order

Here’s the sequence, so you can pre-check most of it yourself. First, drill test holes at both proposed column locations and record actual thickness and whether we hit mesh, rebar, post-tension cable, or radiant heat tubing. Radiant tubing in the floor is a hard stop in the wrong spot, and we’ve found it in more Iowa shops than you’d expect. Second, measure every overhead obstruction across the whole bay. Third, tape the footprint and check arm swing, door clearance, and walking paths. Fourth, verify voltage, phase, amperage, and disconnect location.

Fifth, check floor slope and note where shims will be needed. Sixth, confirm the delivery path: door width, turning radius, and whether you have a forklift or need us to bring rigging. Several customers have told us mid-conversation that they have a forklift on site, which simplifies the whole day. Seventh, review the vehicle mix and match capacity and arm configuration to it — for most passenger-vehicle and light-truck shops 10,000 lb is right, stepping to 12,000 lb for three-quarter-ton and heavier. Get those seven items settled and the rest of choosing between automotive two post lifts is straightforward shopping. Get them wrong and you’ll be paying somebody to fix concrete around an installed column, which is the most expensive way to learn any of this. Call us at 800-674-9302 and we’ll walk your bay first.