Sealants on Slate Tiles Outdoors

by Sheila Karlson
(Livermore, CA)

Question:
Our contractor told us that there is no need to seal slate tiles that will be installed on our front porch and patio. I have heard that it is wise to seal tiles with silicone which does not cause them to have that artificial sheen, but does protect the tile from staining. Should outdoor tile be sealed?

Answer:
It is always best practice to seal any slate tiles installed on an exterior installation, not only will it help with preventing staining, it will keep mildew in the winter from forming over the tiles & make them easier to clean, it also reduces the risk of efflorescence, a cloudy white film forming on the surface of the tiles.