Prepare the cracked.
Repairing large cracks in concrete porch.
Cracks in a concrete porch less than three eights of an inch wide can be easily repaired.
The first part of repairing the cement slab is to seal any cracks to prevent them from spreading up into the new layer of concrete that you will use to level the surface.
This helps the repair material to key into the crack creating a mechanical bond in addition to the chemical bond between the patch material and the concrete.
Wet the surface and apply a concrete bonding agent.
Pack a small amount of anchoring cement.
A shop vacuum is also helpful for completely removing dirt dust and loose debris.
How to repair wide concrete cracks.
You will need a tube of vinyl concrete patching material a wet rag a soft bristle brush and a wire brush.
Instead for cracks up to 1 2 inch wide and 1 4 inch deep you should use a polymer based sanded acrylic latex filler that you inject into the crack with a caulking gun and smooth over with a putty knife.
Concrete cracks cannot be patched with concrete since concrete contains aggregate rock pieces that are too large to fit in cracks.
This last option works best to fill large cracks or chipped edges while the other products are suitable for cracks in concrete that are inch wide or narrower.
Clean out the debris with a stiff fiber or wire brush.
After hurricane harvey took out a big tree in my driveway and caused some serious cracks i made a time lapse video of fixing them this is not a how too t.