One way to understand what a good marble installation looks like is to see a bad one. Unfortunately, there are many tile installations that are not done properly, and the end user doesn’t realize there are problems until some time has passed.
At the very beginning, the marble that is used has a direct bearing on the quality of the finished floor. There are grades of perfection in tiles that have to do with how exact the sizes match and how consistent they are to being perfectly square. If cheap tiles are bought at the beginning, the tile setter may not be totally at fault for a poor finished product.
The first concern before marble is delivered to a flooring job is the condition of the floor where it will be installed. Wood framed floors may have structural members that are not true and straight. It is difficult to compensate for severe imperfections in a mastic bed under marble tiles. A good installer will check to see if the floors are in an acceptable condition before beginning to lay marble tile and do not be surprised if the professional installer will say “I do not want to take this job”!
When the floors do not have problems that warrant any special preparation, the flooring contractor accepts that situation, which then makes him the responsible party for the finished product.
Before laying the first tile, the tile setter must determine how the pattern fits into the room. Nothing is more distracting in a square room as to have the margins different from one parallel wall to another. Tile should be laid out so that the width of the tile on one wall is the same across the way when all the tiles are in place.
As tiles are set, they are spaced equally apart from each other and the corners are lined to the same plane so that no corners are left to rise higher or sink lower than others do. Marble is traditionally set with a grout joint of 1/16th inch so that the tiles are very close together and any variation in height becomes very obvious.
A common installation problem with marble and other natural stone is referred to as “lippage.” This causes a trip hazard because tiles are not all flush. If this is a problem with your natural stone floor, a professional restorer can grind, hone, and polish the floor as needed to remedy the hazard.
After the mastic sets to hold tiles to the floor, there should be no noticeable difference in spacing between any of the tiles. If the tile setter did the job properly, there should be no mastic coming out in the grout joints. If it does, it has to be cleaned out to leave space for the grout.
Grout Application and Protection
On polished marble it is best and recommended to use unsanded grout to a 1/16 inch grout line. Using sanding grout on polished marble is not advisable since the sand in the grout can scratch the polished finish on the marble tile.
Marble contractor must ensure that great emphasis is placed on the final cleaning of the marble installation. If grout haze is left on the tile, it would make the entire job look undesirable and it will be difficult to remove from the marble installation.
After grout is applied and dries, the color should be uniform throughout the tile floor. The marble should be cleaned so there are no dull areas on the surface. Depending on the type of grout used, it may need to be sealed to complete the installation.
Protection of the finished floor is important if other trades must come through the area after its completion. People pulling, sliding, and rolling heavy items over the floor can make even a quality installation unsightly.
Thoroughly Examine Finished Job
A quality marble floor installation should be finished up before being turned over to the owner by buffing and applying a sealer to protect the finish. If mastic can be seen coming from through the grout or corners of the tiles are chipped, it is not a good marble installation.