On Wednesday, 13 March 2019 20:49:27 UTC, Mathew Newton wrote:
Just taken delivery of a number of Celotex GA4000 PIR insulation boards and, as shown in the photo below, the 100mm boards in the foreground are extremely wrinkled one foil face, particularly when compared with the completely smooth 30mm and 12mm boards in the background:

http://www.newtonnet.co.uk/permanent/celotex.jpg

The 100mm boards also have an ever so slight bow to them; not enough to cause me an issue but I wondered if the bowing and wrinkles were the result of differential shrinkage within the core?

Any cause for concern?

slight wrinkling like that is immaterial


NT