Slab Jacking: Simple Guide for UK Homeowners
If you’ve noticed a sunken patio, uneven garage floor or cracks in your interior walls, slab jacking might be the fix you need. It’s a method that lifts a concrete slab back to its original level by pumping a cement‑based grout underneath. Unlike tearing out and repouring the slab, slab jacking is quick, cheap and causes minimal disruption.
When Should You Consider Slab Jacking?
Look out for these common signs: a dip in the driveway that collects water, a garage floor that feels soft under a car tyre, or new cracks appearing after heavy rain. If the foundation beneath the slab has settled, the grout will fill the voids and raise the surface. It’s especially useful for older homes where the ground has shifted over time.
Before you call anyone, do a simple test: place a straight board across the suspected low spot. If there’s a gap of more than a few millimetres, you probably have a settlement issue. In most cases, a professional will confirm the problem with a small probe or a laser level.
How the Slab Jacking Process Works
The crew starts by drilling small holes (about 1‑2 cm in diameter) into the concrete at regular intervals. A high‑pressure pump then injects a specially mixed grout through the holes. As the grout spreads, it fills any voids and pushes the slab upward. The holes are patched with a quick‑dry cement mix, leaving the surface smooth and ready for use within a day.
Because the grout expands as it sets, the lift is controlled and even. Most jobs finish in a few hours, and you can drive or walk on the slab almost immediately. The whole process is less invasive than demolition and usually costs between £15‑£30 per square metre, depending on access and the amount of lift required.
Choosing a reputable contractor is key. Ask for references, check if they’re insured for work on structural elements and confirm they use an approved grout mix. A good pro will also give you a clear estimate that includes drilling, material, labour and post‑work cleanup.
After the lift, keep an eye on the area for a few weeks. Small settlement can still happen in the surrounding soil, especially after heavy rain. If you notice the slab sinking again, it may indicate a larger drainage issue that needs fixing before another lift.
In short, slab jacking is a fast, affordable way to restore level concrete without the mess of a full replacement. If you spot uneven slabs or new cracks, get a professional assessment quickly – the longer you wait, the more the ground can shift and the costlier the repair becomes.
