I'd like to bore a 8" hole through 2"x12" rim joist. The hole will be used for a downdraft kitchen vent. Is that 8" hole size ok and up to code?
There are guidelines for boring holes and notches in regular joist, however, are there any guidelines or codes for drilling holes in rim or band joists?
I have never seen an issue with cutting through a band joist. HVAC guys will gut a whole section with reckless abandon, so it seems. If you are not cutting into the joists, you will be fine. I never had an inspector cite a band joist not being cut properly.
It might be wise to make the hole so there are at least 2 joists at least on one side of the cut. The band joists are to stabilize the end of the joists.
I would make the hole larger than 8" for an 8" duct. 8 1/4" minimum. All this assumes the band joist is fully supported by a foundation wall and is not spanning over an area as in going from pier to pier...
