QUESTION

My contractor is installing glass mosaic tile for our kitchen back splash. Our first set of tiles were destroyed because he used a dull blade for regular tile, instead of the recommended glass tile blade. Can you recommend a blade model and brand name that would do the best job of reducing the chipping of glass tiles? A what is the proper way to create an expansion joint for our kitchen back splash?

ANSWER

ANSWER - The proper way to cut glass tile is either with a continuous rim diamond blade either wet or dry.  Also you can cut glass tile with manual tile cutters.  The glass tile is first scored with a scoring wheel and then snapped.  After cutting the tile, the installer should use a rubbing stone to smooth the edges of the tile as it isn't uncommon to get some small chips or jagged edges.

Expansion joints is a type of movement joint.  All tiles should have a movement joint at transitions of planes and transitions to different materials; particularly at restraining edges.  For example, movement joints should be installed where the floor transitions to walls, and were one wall transitions into another wall; such as the vertical joints in a shower.

The movement joint should have a foam backer rod or backer tape at the bottom of the joint, and then filled with an ASTM C920 sealant e.g. silicone.  Some tiles are so thin, that it isn't practical to use a backer tape.   The sealant is designed to only have two point bonding between the adjacent edges of the tiles in order to fully perform as advertised.  Always follow the directions provided by the sealant manufacturer.