Application
Garage floor settlement and polyjacking
Garage slabs are usually poured on backfill that settles over time, so it is common to see a floor dropping away from the walls or toward the overhead door. Where the slab is intact, polyurethane injection can fill voids and lift sections back into position.
Why it settles
- Settlement of backfill placed against the foundation
- Water entering at the overhead door and softening the sub-base
- Plumbing or drain leaks beneath the slab
- Undersized or missing sub-base under original pour
Often suitable
- Floors with a gap at the wall or a visible drop along a joint
- Hollow areas under the slab
- Approach slabs that have dropped at the door threshold
Usually not suitable
- Floors with active heaving or frost-related lifting
- Severely fractured slabs
- Settlement caused by structural foundation movement — that needs a structural assessment first
Risks, drainage and other considerations
- Check for plumbing or floor drains under the slab before drilling
- Stored items and vehicles need to be moved for access
- A structural engineer should be consulted if foundation walls show movement
- Return to use depends on product and site conditions
Lift or replace?
Lifting keeps the existing concrete, so it makes sense only when that concrete is worth keeping. If it is broken up, deteriorated or heaved, replacement is usually the better route. See lifting vs replacement and what affects cost.
Check before you ask
Use the free slab self-check, the area calculator or the photo checklist, then send the summary with your request. See also the visual guides.
Questions
Is a sinking garage floor a foundation problem?
Not necessarily. Garage floors are often independent of the foundation. But wall cracks or doors that stick can signal broader movement, which should be checked by a qualified professional.
Can the floor be lifted with things inside?
Contractors generally need the floor cleared for drilling and monitoring the lift.
Request an assessment
Other applications
Location guides: Calgary, Edmonton, Vancouver, Toronto, Ottawa, Mississauga and more.