Concrete leveling: what it can and cannot address

Can your existing slab be raised?

Slabjacking means placing material under an existing slab. The material may fill open space and help raise the concrete in a controlled way.

It may be considered for a driveway, walk, patio, pool deck, step, or garage slab. Only an on-site review can show if the slab can move safely and what lies below it.

What should you show the evaluator?

A crack alone does not tell the whole story. Show the low edge, nearby slabs, doors, curbs, drains, steps, and walking path.

• The slab is largely intact rather than crumbling into many pieces.
• One or more edges have dropped relative to an adjacent surface.
• The area can be reached with the proposed equipment and hoses.
• The owner can identify water flow, recent changes, and prior repairs.
• The desired finish and acceptable patch visibility are clear.

What will lifting the slab not prove?

A raised slab does not prove that weak soil, water flow, washout, or a leak has been fixed. ACI notes that slabjacking can level concrete without fixing poor soil below it.

If the slab keeps moving, more work may be needed. Heavy cracking, poor condition, or likely future movement can make replacement worth comparing.

What should a written proposal say?

The proposal should name the slab, work area, goal, material, drill points, patch plan, and items not included. It should also say how the lift will be watched.

Ask what the provider saw near drains and moving edges. Ask who protects nearby surfaces and what the warranty covers. A warranty does not mean the slab can never move again.