The grout can develop cracks owing to a number of reasons.
Joint Size and Inadequate Grout Filling
Joint size plays the determinant factor in selecting the type of grout required to fill the gaps between the tiles. If the tiles size is too wide say more than 1/8 inches then it have to be filled with sanded grout. The sand presence in the grout ensures that the grouting layer does not shrink and produce wide gaps or cracks after drying.
people generally use tiles on the walls of the bathroom. This means that if there is a drywall construction near the shower area then it is going to be covered with tiles.
The drywall does allow the moisture to escape and over the period due to constant usage the water gets locked in the walls destroying the entire construction, formation of mold, deep black patches on the floor etc. Effects of Installing Drywall There are many disadvantages of installing drywall beneath the tiles.