Apr 07, 2017/Videos

Guidelines for Marble Shower Restoration (Part 1)

The following guidelines refer to “average” situations. This means there is no way to establish beforehand what the exact sequence of the various steps will be. It will depend on the type of stone, the contingency of the situation: i.e. the depth of the etch patterns, etc.

General Considerations

A shower stall is a very demanding environment from a maintenance point of view, and if everything was not done properly either when selecting the stone and/or when installing it according to precise and very narrow guidelines, there are going to be problems that will inevitably lead to installation failures.

Does it make sense to specify certain types of limestone or slate of sandstone for a shower enclosure that will literally crumble under the action of warm water hitting their surfaces? Could a situation like that ever be solved with the application of a stone sealer or some other “magic potion” in a bottle?


Yet, these situations do occur. And how about when the installation of stone tiles (even the right ones) is delegated to an unqualified setter who makes mistakes that will undoubtedly lead to failures that will eventually require the ripping out of the whole stall? These are not rare occurrences.

So, before we go into the analysis of the actual restoration of the surface of the stones lining the stall of a shower, let’s see how the stall should be installed to begin with.

The sheeting behind the tiles should be waterproof cement-board-not green board.

The plumber prepares the pan of the shower by laying down the proper sheeting of vinyl, and making sure that the “weep” holes are not clogged in the process of mudding and setting. Then, the floor must be installed and properly grouted, prior to the installation of the walls, making sure that proper color-matching caulk is thoroughly applied around the drain. The same color-matching caulk will be used to seal the walls where they meet with the floor and with each other. All the tiles (floor and walls) must be installed leaving 1/16” grout gaps (particular attention must be paid when grouting).

We’re not talking about your regular wall and floor here: tiled shower stalls- whether ceramic or natural stone- represent a very delicate and demanding environment because of the heavy-duty nature of their use. There is quite a difference in use between the walls of the bathroom outside the stall, and the same walls inside it. The sand-less grout must be kept on the thick side and painstakingly pushed deep between the tiles using a flexible blade plastic putty knife, rather than your regular grout floater. Tile and caulk are vital components of the installation of a shower stall. “Butt-joint” installation is simply put, plain disgraceful and there should be precise standards by which to hold the installation contractor accountable for any future installation failure die to a butt-joint installation. The grout applied to tiles butt-jointed to one another will only fill the “V” groove created by the bevel of the tiles coming together, but it’ll have no root and it won’t last long under the action of the hot water and steam that a shower stall will be submitted to, and the extra scrubbing that its proper cleaning will require.

Why is this information important to the stone restoration contractor?

Because if, by any chance, water finds its way behind the tiles and, by gravity down under the floor tiles and maybe the “weep” holes are somehow clogged, all sorts of unsolvable problems develop, like excessive mildew, spalling of certain marbles and granites, efflorescence with some other stones, rusting of iron mineral-rich rocks, and so on. In a nutshell, should this happen, it’s actually a failure of the initial installation- the only solution would be to rip out the whole shower enclosure and start anew.

The stone restoration contractor must be able to detect and recognize these sorts of problems in order to understand whether or not his professional interventions would be of any use. In most of these cases, unless the stone restoration contractor is also an installer, or is connected with a reputable tile setter, there’s not much that he or she can do other than break the bad news! A good pre-qualification of the prospective customer over the telephone, asking the right questions should generate enough red flags to make the stone restorer realize that his visit will not represent the opportunity for an estimate, but will most likely be a full-fledged consultation to find out what the real problem is. Consequently, the request for an appropriate consultation fee will be legitimate and in order.

Assuming that everything checks out and the request for restoration services is legitimate and based on the right grounds, let’s see what the procedure is going to be. However, before we go into that, one “curious” and not-so-rare situation must be taken in consideration: the shower stall could possibly just be in need of a good clean. Many customers neglect their stone or do not use the correct products to remove certain issues such as soap film and mineral deposits. A good cleaning will only be necessary in this case.

Let’s look now at the actual restoration; but keep in mind that when restoring a marble shower stall; you will have to deal with encumbrances such as faucets, stoppers, shower heads, soap-holders, etc.

It is important to let the customer know at the time of the estimate (in writing) that the areas immediately near those obstacles will not be restored as properly as the rest, unless they are removed before the commencement of the job. In the case of small soap-holders (typically made of marble tiles cut in half at 45 degrees), it will be technically impossible to restore them, because the overlapping of the steps necessary to complete the job will not be possible.

End of Part 1

For more detailed information and step by step instruction, purchase our Natural Stone Maintenance Book or consider attending one of our Stone Restoration Training Classes in Wilson, NC.

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