How To Fill Void Under Concrete Slab

These need a method that supports but doesn t lift the slab.

How to fill void under concrete slab.

Once there voids are difficult to fill. Filling voids under concrete slabs can help ensure the slabs will not sink or settle into the voids and prevent the need to replace concrete slabs. Drill at least four holes through the slab at a point that s centered on the void beneath. There are several ways to fill material under a concrete slab and remove voids.

There are several conventional and alternative void filling materials which can be employed to achieve a similar effect. Connect a hose to a slabjacking pump then run the hose to the holes leading to the void. Smaller slabs such as walks can be packed with gravel or sand to fill voids but this is not practical for larger slabs such as driveways or patios. Slabjacking is as the name might suggest raising up all or part of a concrete slab.

A sand cement grout can be used to fill voids under concrete slabs. How to fill voids under a concrete slab step 1. Rather than using a mechanical jack as you might with a car soil and other material is used.