by Margaret
(Cookeville, Tn)
Q. We just built a new garage. We sealed the concrete slab before any other building was done. The garage is now finished and the concrete floor looks awful...scratches (big and small). We initially used an oil based clear sealer. Can we now apply a tinted oil based sealer without removing the sealer that is already on the concrete floor? Would any oil based colored concrete sealer adhere to our previously sealed surface?
A. As long as you use the same type of concrete sealer (oil/solvent based) that you previously used, you don't have to remove the sealer already on the concrete floor. You can seal right over it with a tinted or clear sealer.
As a rule of thumb: solvent based concrete sealer can go over bare concrete or a concrete floor previously sealed with solvent based sealer, it cannot go over any surface previously sealed with water based concrete sealer.
Water based concrete sealer can go over bare concrete, and surfaces previously sealed with water based or solvent based sealers.