I want to put some new concrete on top of an old patio. Is there anything that I should or shouldn’t do?
I’m not fond of capping existing concrete, but it can be done. Usually, the new concrete is at least three inches thick. I find anything less than that has problems. Get a mix with pea gravel in it rather than ½ inch or larger rock. To help with bonding to the old slab I also apply a concrete bonding agent to it before placing the new concrete. After that, pour and finish as usual.