My builder said not to seal my floors
Many builders do not recommend sealing stone or tile. Consider this: I have yet to meet a builder that seals stone. The only time stone is sealed is to change the appearance of a stone or at the request of the home owner. Thus, I get asked the question all the time if sealing is a good idea.
Sealing stone or tile grout is essential to maintaining the life of a stone and/or grout. From my experience with cleaning stone floors and tile grout, I have found that an unsealed floor does not come nearly as clean as a floor that was originally sealed. Sealed stone or grout restores 95-100% like new with a professional cleaning. While an unsealed surface restores only 80 to 95% like new with the same professional cleaning.
The reason is simple: Sealers keep stains, oils and dirt at the surface and do not allow deep penetration. Although our cleaning methods have come along way to reaching deep into the stone and tile grout to lift dirt. It is nearly impossible to get 100% of the deepest stains.
