Slabjacking Made Simple: How to Lift Sunken Floors

If you’ve walked into a room and noticed a dip in the floor, you’re probably looking at a slabjacking job. Slabjacking is the cheap, quick way to lift a concrete slab back to level without tearing out the whole floor. It’s a favorite for homeowners who want to avoid big demolition costs.

What Exactly Is Slabjacking?

Slabjacking, also called mudjacking, involves drilling small holes in the concrete and pumping a cement‑based mixture underneath. The pressure pushes the slab up, filling the void that caused the dip. The result is a flat, stable surface that’s ready for flooring, furniture, or just walking on.

When Should You Choose Slabjacking?

Not every floor problem needs slabjacking. It works best for these situations:

• Minor to moderate dips (typically up to 2‑3 inches).
• Cracks that are more cosmetic than structural.
• Homes with a stable foundation but settled soil under the slab.
• Projects where you want to keep the existing flooring in place.

If the slab is severely cracked, water‑logged, or the foundation itself is unstable, you’ll need a more extensive repair.

The Slabjacking Process in Plain Terms

Here’s what a typical job looks like:

1. Assessment: A pro checks the dip, measures depth, and decides how much material is needed.
2. Drill holes: Small (about 1‑2 inches) holes are made at regular intervals across the low spot.
3. Mix and pump: A lightweight cement slurry is pumped under pressure through the holes.
4. Lift: The slurry fills the void and raises the slab. The professional monitors the level in real time.
5. Seal: Once level, the holes are patched with a quick‑setting concrete mix.

The whole process usually takes a few hours, and the floor is ready for use the same day.

Cost and DIY Considerations

Professional slabjacking runs about $5‑$12 per square foot, depending on location and depth. That’s far cheaper than tearing out and replacing a slab.

If you’re handy, a DIY kit is available for smaller jobs. You’ll need a drill, a pump, and the right mix. DIY savings can be significant, but you also risk uneven lifts or missed voids. A mis‑lift can cause new cracks, so weigh your skill level carefully.

Tips to Get a Successful Lift

• Check drainage – water pooling around the slab can cause future settling.
• Ask the contractor to provide a “lift plan” showing where holes will go.
• After the lift, keep the floor dry for at least 24‑48 hours before installing heavy items.
• Consider a sealant on the concrete surface to protect against moisture.

Following these steps helps the slab stay level and avoids repeat work.

Common Mistakes to Avoid

Don’t skip the inspection. A hidden foundation issue will keep resurfacing no matter how many times you mudjack. Also, avoid using cheap, low‑grade mix – it can crack and lose strength over time.

Finally, don’t rush the curing time. Even though the floor feels solid right away, the material continues to set for a few days. Heavy loads too early can sink the slab back down.

Slabjacking is a practical fix for many uneven‑floor problems. Whether you hire a pro or try it yourself, understanding the basics ensures a smooth, level surface that lasts.