Joists that are spaced too far apart will allow for deflection in the plywood subfloor, thus allowing the finish floor tile to bend–which it does not want to do. Even though concrete seems like the perfect substrate for tile, it too has its own problems. Also avoid sand and acidic liquids, since they can burn into the marble surface and possibly cause hairline cracks. Make sure to trace furrows in the mortar with the notched edge, as this will help the tile adhere to the subfloor.

DonÂ’t apply too much, and do your best to direct it down into the grooves, and off the surface of the marble pieces. At the same time, you want to get as much grout out as possible so that it will be easier to remove the tile itself. While you should use some force, you donÂ’t want to get carried away and hit the marble too hard,Â… As you do this make sure that you maintain a shallow angle with the chisel, as you do not want to accidentally drive it down and damage the subfloor beneath.

You will then want to allow the adhesive to thoroughly dry over the course of the next 24 hours.

In this test, floor tiles are run through a machine that exerts load on an unsupported 1-inch square area. If the crack is located in one area, extending across only a single tile, this is probably the case.

Chances are good that this concrete, if it is a few years old, has a long crack or two running through it. When concrete substrate cracks, this is transmitted to the tile above in the form of a reflective crack. Any rises or depressions in this surface will act like bubbles of weakness beneath the tile and may lead to further cracking down the line.

This will show you what it will look like ?no your floor and will let you gauge how closely the colors match up.

This may not be necessary, but seal does have a subtle effect on this materials sheen and surface gloss.

Start by taking the tip of your nail press, and placing it against the center of the tile.

That will create an invisible barrier over the tile so that adhesive and mortar will not damage or stain it. Applying a coat to the entire installation will help to create a sense of uniformity in the room.



Source: www.tiletoria.co.za/news/7-reasons-floor-tiles-crack/
genaMarble
Joists that are spaced too far apart will allow for deflection in the plywood subfloor, thus allowing the finish floor tile to bend–which it does not want to do. Even though concrete seems like the perfect substrate for tile, it too has its own problems. Also...