Designing Kitchens and Bathrooms - Concrete countertop

I moved into a house with concrete countertops in the kitchen. I don't know if they were sealed. How can I seal or reseal the countertops? Do I need to wax or put down some sort of periodic coating? Nothing in this house was installed or fitted properly, so I suspect the countertops were not sealed.

To see if a clear sealer was applied in the past, test the surface by sprinkling either muriatic or phosphoric acid, which you can find at your local home improvement store, on the surface. The acid will bubble on contact. If it continues to bubble, it's likely that the surface is not sealed. If the acid does not bubble after initial contact, that is an indication that the surface is sealed.

Good luck!

I would not suggest the above test, if it is unsealed you could ruin the surface finish. Check with someone that does concrete tops, someone in your area should know.

actually the above test would work OK if you chose an inconspicous location to test it and only used the smallest amount (like using a small paint brush - like one you would use to paint a model plane with - and dabbing the smallest amount [one drop] on the surface). The reaction should be immediate and be ready to wipe it off immediately followed by wiping it down with water. I would use Muriatic as it will generate vigorous fizzing on an unprotected surface, but is not as strong (and damaging) as Phosphoric (plus muratic acid is good for cleaning concrete)