Settlement cracks

Over the years I have heard so many remedies regarding preventing settlement cracks in the sub-floor or concrete from damaging the tile floor to be installed over it.

The only logical means of preventing it - in my opinion - is to install a membrane between the crack and the tile above it. And then hope that the movement is not too great beneath that membrane. For excessive movement can disturb the membrane too! And I have seen that such cracks, if the direction should change and the crack close again - has the result of causing a floor to buckle in that area.

Rubberized matting is sold, or sheet vinyl, for instance, but a necessary component is luck too!