My builder just finished our condo and during our final walkthrough he recommended sealing our ceramic tiles in the bathrooms and kitchen backsplash and also sealing our granite countertops. Any comments or recommendations? Do builders usually seal these while building? Do most people do this or even know to do it?

Most big box stores or anywhere that tile products are sold will carry a spray grout sealer. Some you spray and walk away, others you spray, let sit and then wipe dry. If you make the purchase I would rather deal with a tile store, as I am not a big fan of the working knowledge of Big Box employees.
Should your builder have sealed his work, in my opinion yes, but it may have not been in his contract, odd as that would seem. Or maybe he was cheap or just plain lazy.
Can't answer your last query, that would be anyone's guess.

This message has been edited. Last edited by: CommonwealthSparky,

Some builders subcontract the tile portion etc. out to others. The subcontractor may or may not have sealed the floor, to be on the safe side the builder recommended re sealing it. Either way, I think the builder is good for mentioning it, you can't over seal it.

Hi
My friend works for a tile distributor and they recommend Porus Plus for stone and marble.

Good Luck!