Canada Better Wood?
Must be good stuff. Not so fortunate south of you. During construction my house got rain for only a single day before it was under roof and the Georgia Pacific OSB flooring still swelled at the seams. Granted it was a drenching rain and work on the house paused for a few days thereafter. Eventually the contractor sanded it flat before flooring was put down.
Here is an excerpt from a company that sells engineered lumber processing chemicals. What they describe is exactly what I experienced:
IntroductIon
Many building material deficiencies are so common that builders have stopped
searching for solutions. Instead, they just manage around the poor product
performance. Case in point: wood swells when it gets wet. It’s a law of nature. For
instance, when OSB panels are used as subfloor and it rains during the construction
process, or the panels are otherwise exposed to moisture (a very common occurrence),
they typically swell when water wicks into the edges. This situation is so widespread
that it’s not uncommon for builders in wet climates to actually budget for subfloor
panel-edge seam sanding on every job. Builders in drier climates will sand only as
required. But in every case, the sanding is an added expense that runs at least a couple
hundred dollars, to say nothing of the nuisance of scheduling the sander—you can’t
sand OSB when it’s wet, for instance—and dealing with the annoying chips and dust.
