Key Takeaways
- Most two post lifts need at least 150 mm of 3,000 psi (C25) concrete, cured 28 days.
- Never anchor across cracks, expansion joints or within 150 mm of a slab edge.
- Use the anchor bolts supplied and torque them to the value in the manual.
- If the slab is thin, pour new footings under each column.
A lift is only as strong as the floor it is bolted to. Anchor bolts transfer the vehicle load, the column's overturning moment and every bump during service into the slab. Here is what the floor must provide.
Minimum specification
| Lift type | Minimum thickness | Minimum strength | Anchoring |
|---|---|---|---|
| Two post | 150 mm (6 in) | 3,000 psi / C25 | Required, every column |
| Four post (service) | 100–125 mm (4–5 in) | 3,000 psi / C25 | Recommended |
| Four post (parking, mobile) | 100 mm (4 in) | 3,000 psi / C25 | Not required |
| Scissor (surface) | 100–150 mm | 3,000 psi / C25 | As per manual |
Always follow the installation drawing supplied with your specific model; heavy-duty and 5–6 t lifts may require more.
Curing and condition
- Let new concrete cure for 28 days before anchoring.
- The floor should be level; small variations are corrected with shims under the base plate, but slopes are not acceptable.
- Keep anchors away from cracks, saw cuts and expansion joints, and at least 150 mm from any slab edge.
How to check an existing floor
- Drill a small test hole at each column position and measure the depth.
- Look for cracks, spalling and old repairs in the column footprint.
- If you are unsure of strength, ask a local engineer to core-test the slab.
When the slab is not good enough
Cut out and pour new reinforced footings under each column — typically 1,200 × 1,200 mm, 300 mm deep for a two post lift — and let them cure before installation.
Anchors and torque
Use the anchor bolts supplied with the lift, drill to the correct diameter and depth, blow the dust out of the hole and torque to the value in the manual. Re-check torque after the first week and then monthly as part of your lift safety inspection.
FAQ
How long after pouring concrete can I install a car lift?
Allow the full 28-day curing period before anchoring a lift. Early-age concrete has not reached design strength and anchors may pull out.
Can I install a lift on a floor with radiant heating?
Only if the heating pipes are mapped and fall outside every anchor location. Scan the slab before drilling.
