Auto Lift Install Prep: A Site Survey Walkthrough on the Iowa-Nebraska Border

A service manager at a franchise dealership near the Iowa-Nebraska border called us in January with four bays to re-equip and a delivery date he couldn’t move. He’d already signed off on the equipment. What he hadn’t done was measure anything past the bay width, and that’s how a straightforward auto lift project becomes a three-week delay. We spent a morning with a tape, a laser, and a clipboard, and by lunch we’d found four problems that would have stopped the install cold. This article is that site survey, written out with the actual numbers, so any shop owner or service manager can run the same checklist before the truck shows up with a crate on it.

Measurement One: Real Ceiling Clearance, Not Nominal

The building was spec’d as 14-foot ceilings. The lowest obstruction in bay two was a 3-inch sprinkler main hanging at 12’1″ to the bottom of the pipe. In bay three, a run of conduit and a fluorescent fixture put the low point at 11’8″. That’s a huge difference when an overhead-style two-post crossbar sits around 12 feet and the vehicle still has to rise underneath it.

Here’s how we measure: laser from the finished floor to the underside of every obstruction across the entire footprint the columns and crossbar will occupy, plus three feet on either side for a technician’s head and a raised hood. Then we subtract nothing and add nothing — we write down the smallest number in the bay and design to it. In bay three we switched to a floorplate model, which routes hydraulic lines and the equalizer cable through a low channel at the floor instead of over the top. It cost us a small trip hazard in exchange for eight additional inches of usable rise, and for a bay doing daily oil, tires, and brake work that trade was obvious. The service manager’s original plan would have put a crossbar three inches into a sprinkler line, which is the kind of mistake that involves the fire marshal.

Measurement Two: Bay Width, Door Swing, and Drive-Through

Bay width measured 13’4″ wall to wall in the two end bays and 14’2″ between the interior columns of the building. Column-to-column spacing on the model he’d chosen was 11’6″ inside, with a 12’2″ overall footprint including baseplates. On paper it fits. In practice you also need room to open the vehicle’s doors while it’s raised, walk a transmission jack around the outside of a column, and get a rolling toolbox past without gouging a fender.

We chalked the footprint on the floor and had a tech pull a crew-cab pickup and a mid-size SUV onto the marks. The pickup’s mirrors cleared, but the driver’s door contacted the column arc at full swing on the near-wall bay. Shifting the whole footprint 9 inches toward the center of the building solved it and cost nothing, because we caught it before drilling. We also confirmed drive-through width — the clear space between the columns at the base — because this dealership drives vehicles straight through to a wash bay behind. A wide-drive-through configuration was the right call there even though it added modestly to the price. Layout mistakes in a dealership don’t just annoy one owner; they slow down four techs every single day for fifteen years.

Measurement Three: The Slab and What’s Buried In It

The building was 11 years old with documented 6″ slab at 4,000 PSI, and coring confirmed it — 5-7/8″ and 6″ at the two test spots. That’s excellent. But dealership floors are full of surprises: trench drains, radiant tubing, post-tension cable in newer commercial pours, and old inground lift casings that were abandoned in place rather than removed.

We ran a GPR scan on two of the four bays because the original drawings showed a floor drain line crossing at an angle nobody could account for. It was there, 4-1/2″ below the surface, running diagonally through what would have been the driver-side column footprint in bay four. Drilling an anchor into a drain line is a bad afternoon. We rotated that bay’s layout 18 inches and re-chalked. In bay one we found the abandoned casing of a single-post inground unit from the building’s previous life; we left it alone and simply placed the new columns clear of it. The general rule we give every shop: if a slab has any history at all, scan before you drill. It is cheap, non-destructive, and it is the single highest-value hour in the entire prep phase for any commercial auto lift installation.

Measurement Four: Power, and the 220V Question Everybody Asks

“Do I need 220V?” is easily the most common question we field, from home garages and dealerships alike. For nearly every 10,000 to 12,000 lb two-post with a single-phase power unit, the answer is yes — 208 to 230V, typically on a 20 to 30 amp circuit depending on motor size. Some smaller mid-rise and portable units run on 120V, but they’re slow and they work the motor hard. This dealership had three-phase 208V available at the panel, which is ideal: faster rise, cooler motor, longer life.

What they did not have was a disconnect within sight of each bay, or receptacles located where the power unit would actually sit. Two of the four planned positions put the power unit on the opposite column from the nearest outlet, which means either a long cord run across a walkway or an electrician’s visit. We wrote both into the prep list with a note: get the electrician in before install day, not during. We also flagged that the power unit needs to be on the column the techs will stand at, because reaching around a raised vehicle to hit the down handle is how people develop bad habits. Confirm rotation direction on three-phase before first lift, too — a motor spinning backward pumps nothing and gets blamed on the pump.

Measurement Five: Drains, Slope, and Shim Planning

Shop floors slope. This one sloped roughly 1/8″ per foot toward a center trench drain, which is good drainage design and a mild nuisance for column plumb. Across a 12-foot footprint that’s about 1-1/2″ of fall — meaning one column baseplate sits meaningfully lower than the other and must be shimmed to bring the column plumb.

We measure slope with a laser across each planned baseplate location and record it, so we bring the right steel shims instead of improvising. Manufacturers specify a maximum allowable shim stack, and if the slope exceeds it, the correct fix is grinding the high side or pouring a leveling pad — not stacking shims until it looks straight. We also plan the layout so no baseplate straddles the edge of a trench drain, because anchor pullout strength depends on having concrete in all directions around the hole. On this job, two of the four bays needed shims under 1/2″, one needed 3/4″, and one we oriented differently so the fall ran across the short axis instead of the long one. Ten minutes of laser work per bay produced a parts list and a plan. Skipping it produces an install crew standing around at 2 p.m. waiting on a hardware store run.

Building the Prep Punch List Before Delivery Day

By the end of the morning we had a one-page list per bay: obstruction low point, chosen configuration (overhead versus floorplate), footprint dimensions and offsets from the wall, core results, GPR findings, electrical work required, shim stack per baseplate, and vehicle mix. We handed it to the service manager, he handed the electrical items to his contractor, and delivery day was uneventful. Four bays went in over two and a half days with no re-drilling and no change orders.

What made it work wasn’t skill on install day. It was that every decision had already been made on paper with real numbers attached. We tell every customer the same thing: the prep phase is where projects succeed or fail. Ninety percent of the delays we see — and we’ve seen them at dealerships, independents, fleet shops, and farm buildings across Iowa and eastern Nebraska — trace back to a measurement nobody took. If you want the same survey done on your shop, we’ll come out, measure it, and put the numbers in writing. Call 800-674-9302 or email us. You may also want our articles on two-post lift concrete requirements and annual lift inspection requirements, both of which pair well with the planning stage of any auto lift project.