I get this question all of the time.
The fact of the matter is that you can cut holes big enough in an I-joist big enough to put ductwork in.
Weyerhaeuser makes it easy with this simple chart.
Keep in mind though, if you need to make a hole that doesn’t fit the mold you can always call us at Parr Lumber. We have the ability to work with Weyerhaeuser’s engineers to come up with a solution for most situations.
For more information check out Weyerhaeuser.com