Page 4 - 2017-07-CFR Volume 106 - The Difference Between Dimensional and Planar Stability - July 2017

the substrate doesn’t have to be flat and level to in-
stall their products but it does. If it isn’t, as men-
tioned, the material can run off, be distorted, have
hollows beneath it, squeak, creak, flex, crack and
maybe do some things we haven’t thought of yet;
who knows.

Gluing unstable flooring direct to the substrate will
not hold it stable or flat; that is not the purpose of ad-
hesive. It’s laughable to hear someone say that
pressure sensitive adhesive once applied will make
the flooring material and substrate one unit. Not go-
ing to happen. If the material is unstable it’s going to
move and adhesive, nails, screws or bolting it aren’t
going to stop it. The stresses being relieved in the
material are going to react and nothing is going to
stop them. Sooner or later an unstable product will
manifest an inherent stress. It may be in days or
months but if its unstable it will happen.

Gaps from tile shrinking over a hot substrate

New plank laid over a shrunken plank. Shrunk over
1/8 inch
4 Commercial Flooring Report July 2017