I never worried about manufactured wood and shrinkage until recently. I was just called out to look at a 3 year old project that had issues with the glu-lam beams and shrinkage which caused the fire sprinkler line to leak where it penetrated a masonry wall. A very large 72” deep glu-lam beam in the gym shrank about ¾” total in depth after construction. Glu-lams will suck up moisture and grow after fabrication before or during construction (I have pictures of the beam exposed probably 3 months before the building was fully enclosed and heated) and then shrink as the moisture level reaches equilibrium. See attached link for good information.
http://www.rosboro.com/pdfs/EWS-Y260.pdf
Peder Golberg
Portland, Oregon