Drilling Holes in Manufactured Floor I-joists - with Pictures

Good day

I had a pre-drywall walkthrough yesterday and was surprised at how much they drilled into the floor joists to accommodate a plumbing line.

Judging by the photos attached, would this weaken the joists?


Why not ask the manufacture if this is OK .


Thanks for the reply but I was hoping experts here could provide advice based on the pictures.

Photo 2 is not an issue as it’s not structural. As for photo 1, it looks ok since I joists are much different than dimensional lumber. But as others have already replied, every manufacturer has their own specs.

Here is a spec chart for the TJI 4000 joist.

The outer 1/3 is more critical than the middle third on TJI joist. But, it has been my experience that the TJI engineers can provide remedies for almost anything a contractor will do to these. I usually just called TJI and spoke with the engineer dept. Often I found that a TJI rep had already been on site and informed the contractor it needed repair or was ok (although their advice wasn’t always followed). Even the worst case I saw the fix wound up being a metal strap secured to the bottom of the TJI that extended past both sides of the hole. Best bet as suggested above, call the TJI engineers Engineered Wood Products Technical Support:1-888-453-8358

No issues Read up on TJI’s you will see a lot of them. Do not allow them to use fiberglass insulation in the rim joists.

Can you please expand on this? Is it because it’s a poor practice? What if they properly seal the poly?

Fiberglass batts are no longer recommended choice to be used at the rim space because it’s nearly impossible to install a proper vapor barrier there, and fiberglass batts will allow for a lot of air leakage. Without a vapor barrier at the rim space, you’ll have relatively warm, moist air passing through the fiberglass insulation and then condensing at the rim joist. This may create moisture problems in cold climates. If you spray foam or seal with rigid insulation and then add fiber glass ok… I will find frost and mold behind most engineered rim joist. When we first built with TJI we used fiber glass but we quickly learned the lesson always check behind fiber glass insulated rim joist especially under doors.