I’m buying a new home with glazed through-body porcelain tile in one of the bathrooms. I’m unclear about whether I need to seal the tile and grout or just the tile. Will it hurt the tile if I put sealer on it?
If the tile is glazed, there is no need (and no point) to seal it.
If the tile is unglazed and/or a full-body tile (i.e. the pattern goes throughout the tile and is not just on top) then sealing will help with reducing moisture absorption.
Here is one site (they sell tile, but it’s fairly informative) with more information.
http://www.builddirect.com/Porcelain-Tile/Ceramic-Tile-FAQ_6933.aspx#What is the difference between standard ceramic tiles and porcelain tiles?
Roddy
Just the grout.
Often grout sealer is applied to the entire surface and wiped before it dries. It is absorbed by the grout but wipes off a glazed surface. It will not harm a glazed tile but will leave ugly streaks that will take a few months to wear off if allowed to dry.
Sealer is a euphemism for these products, they should be called ‘temporary film that sort of reduces staining for a limited period of time’. You should reapply yearly. The add little to no water resistance, even when newly applied.