Occasionally, concerns arise about notches or holes cut in Trus Joist® (TJ) products used in continuously supported applications such as rim.
Rim is not a structural member in the traditional sense, as it is generally not required to span a distance while supporting vertical load. The purpose of rim in conventional construction is to provide lateral stability and transfer vertical loads through the structure. For this general usage, sporadic holes and/or flange notches are not critical.
From a code standpoint, if the rim is in the proper location and properly connected, no other requirements are given to gauge performance. Dimension lumber band joists are often cut for wiring holes, air ducts, etc. The criteria for judging continuously supported TJ products should be similar to that used for continuously supported dimension lumber; i.e., occasional holes and notches have little impact on their function so long as there is not a large point load located above the hole.
Likewise, notches in the flanges of continuously supported TJI® rim joists are often permissible. Joist flanges resist bending stresses when a joist is spanning from one support to another. When joists are continuously supported the flanges can be cut with no impact because the joist is only transferring vertical loads.
For information specific to holes in TJ® Rim Board, TimberStrand® LSL, TimberStrand® LSL Rim Board, and TJI® rim joists see Guidelines for Notches in Rim Board TB-224.