How To Pour Concrete on an Existing Concrete Slab

Measure the existing slab. Then measure, mark and cut two-by-fours with a circular saw to make forms that will go along the top edges of the existing concrete slab.

Drill pilot holes into the side edges of the existing concrete slab using a masonry bit. These holes will be used to affix the forms along the top border of the concrete slab.

Fasten 1-inch by 3-inch stakes to the two-by-four forms with a screw gun and stainless steel screws. Then fasten the stakes to the side edges into the pilot holes using a screw gun and cement screws.

Combine one part Portland cement with three parts sand in a wheelbarrow, moisten with a hose and mix together with garden hoe. Add gravel, if desired, to strengthen the concrete.

Pour concrete bonding agent onto the existing concrete slab while the new mixed mud is still wet. Immediately spread the newly mixed mud over the bonding agent.

Smooth the surface of the wet mud with a trowel and allow to cure for a period of 24 hours. After 24 hours has passed, remove the screw securing the forms with a screw gun, then tap the forms off the existing slab with a hammer.