Shrinkage and Laminate Seam Tightness

As a wood-based product, laminate changes dimension in response to variations in ambient moisture. This can create gaps at joints or seams. April 4, 2011

Seams with laminate on straight walls and curved walls are tight in the shop. At the job sight with the heat on, the laminate seams are opening up almost 1/8". What are techniques used to prevent this? We use spray applied contact cement and hand rollers. Are there other adhesives, techniques, or methods for us to try?

Forum Responses
(Adhesives Forum)
From contributor B:
No, laminate is made of paper, a wood product. It changes dimension with changes in humidity, simple as that.

From Gene Wengert, forum technical advisor:
I agree with Contributor B. Let me add that changes in humidity (the humidity will drop from 100% RH to about 20% RH when heating air 30 degrees F. This is equivalent to changing the wood by 25% MC to 5% MC) cause changes in MC and then changes in MC causes changes in size. As a rough rule of thumb, a 20% RH change results in about 1% size change. Do you know your shop RH or the MC of the wood when it left your shop? Do you know the heated location's RH? Radio Shack has a small, digital RH measuring unit for $25 which works very well for determining the RH in these sorts of situations.

From contributor S:
I have had moderate success using carpenters glue on the seams and contact for the rest of the sheet. On commercial counters, etc. you leave about a 1/2 inch on both sides of seam with no contact cement then just before applying laminate put the glue on. Someone should invent an expansion joint for laminates.