Question
We have a project where the Norbord TallWall sheathing was used on modular construction and was allowed to get wet. The contractor is taking moisture content readings and would like to know what the maximum moisture content should be before he can close the walls back up.
Tim Hardy, Colchester, VT
Answer
Thank you for the e-mail and question Tim. I think the APA (The Engineered Wood Assoc) document here is probably the best way to address the contractor’s question. I will say that at it is very difficult to get moisture readings from OSB panels because of the layup and some readers only give you the highest content it passed through. The best way I have heard of for taking moisture readings in OSB is to take about 6 or 8 readings spaced about evenly throughout the panel and take an average of the readings.
Keep in mind that TallWall is an OSB panel that happens to be either 9′ or 10′ long so he should treat TallWall the same way he would any other OSB panel. Of course the more time drying the better and the house wrap will breathe as well.