Recently, I have had several calls about restoring Slate Showers in master bathrooms. The story is the same: My Slate is 8 months old and is already turning white, why and what can be done? Or my slate is 5 years old and we are putting the house on the market.

There are two types of white that can be present in your shower, a third that encourages the white to appear sooner. 1) Efflorescence 2) Soap scum/Hard Water 3) Cleaning the shower with the wrong chemicals

Efflorescence. When water travels through stone or grout, the water evaporates and leaves salt behind. This salt may be a white powdery deposit on the slate or it can be a rock hard crystallized deposit in the grout lines. GOOD NEWS FIRST, the white powdery deposit can be removed and prevented with simple measures. However, (The BAD NEWS) the crystallized deposit in the grout lines may be nearly impossible to remove (We can usually get 80-98% of it gone). And that is not the bad news, the bad news is that this type of crystallized formation is a result of a crack in the grout line. Most likely, moisture is traveling down the cracks and pushing the salts up. If this is the case, I would recommend calling a tile installer to replace the stone floor in your shower.

Why replace? Under your slate tiles, the water has been trapped for a long time. Possibly causing mold, mildew and weakening the bond of the tiles to the floor. Additionally, even if we remove this crystallized salt, it will come back until the source is corrected. Side Note: I have seen the tiles actually have significant give/play when stepped on due to being over saturated with water. PREVENTION: Sealing the stone with a penetrating sealer help prevent water from traveling through the stone. Secondly, if you see your grout cracking, put some caulk in the gap that matches closely to your grout color. Or have it re-grouted before the moisture has time to create a problem.

By the way, it is common for grout to crack or separate from the tile’s edge. This can happen for so many different reasons and I do not want to get into them all on this blog entry. But I just wanted to note that it is something to watch for and catch before trapped moisture under floor is able to create problems.

Soap Scum/Hard Water: Most people are educated on hard water deposits and understand its effects. Soap Scum is the same. Soap is made up of calcium/talc or some other minerals that are not absorbed into water. Thus, water can not carry soap down the drain. It usually makes it half way out the shower and then attaches to the walls 3-4 feet up from the drain. Good NEWS: This can be professionally cleaned off and removed. PREVENTION: one can wipe the walls with a microfiber rag or sponge after each use (or use squeegee when possible). Once a week, use a Stone Cleaner and a microfiber rag.

Cleaning with wrong cleaners: Strong bathroom cleaners will attack and breakdown the sealer. Once the sealer is weakened, water has an opportunity to start causing problems. Thus, the more often people use these strong bathroom cleaners. This cycle is the most common reason why people have problems. PREVENTION: Seal stone properly, wipe shower daily, clean weekly with a stone cleaner, inspect grout for cracks. These easy to follow tips will keep your slate looking good longer. If you start to notice a problem, it may be time to have your slate resealed. Slate in a Master shower gets a ton of use and may need to be resealed more often. Especially if you have problems with hard water.

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.