How do I fill voids in the ground under an existing concrete porch?

Answer by  hibpmgirl (2166)

You can use a tubed pump to insert concrete underneath the exsisting porch. The berst thing to do would be to hire a professional to do this for you. If not done carefully you could risk damaging the exsiting porch by over filling the voided areas which will lead to cracks when the under side dries.

Answer by  fiddlefaddle (883)

There are products to fill gaps. Try your local hardware store and ask for assistance on which filler is best.

Answer by  eyeguy (3760)

Cut or drill a 12 inch hole over the voids. Compose a mixtue of sand rocks as your filler. Once you have located your voids fill, then top with concrete.

Answer by  grandmaG (26)

Piers are needed under the slab, or the slab can be removed or replaced. The void should be filled with pressure grout in through the weak soil down to the solid ground.