drill 4" hole through rim joist???

Old 09-15-06, 10:50 AM
Thread Starter
Join Date: Mar 2006
Posts: 12
Upvotes: 0
Received 0 Upvotes on 0 Posts
drill 4" hole through rim joist???

In order to install a bath fan in a main floor bathroom with a finished floor above it, is it an acceptable practise to drill a 4" plus hole through a rim joist?? my regular joists appear to measure 7.5"x1.75" so I would assume the rim joist would be the same...

Old 09-15-06, 03:57 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 36,607
Upvotes: 0
Received 9 Upvotes on 8 Posts
Answered in another forum.. Cut a 4 1/4" hole or you won't be able to run the duct nor attach the flap outside.
Old 09-23-06, 07:58 PM
pgtek's Avatar
Join Date: Oct 2004
Location: north Carolina
Posts: 1,348
Received 1 Upvote on 1 Post
no no

you cant drill a 4 in hole in a 2x8
max would be 1 1/2
why not run between the joist and cut hole in outside wall
Old 09-23-06, 08:16 PM
Join Date: Mar 2005
Location: USA
Posts: 5,650
Received 1 Upvote on 1 Post
drill 4" hole through rim joist???

A rim joist is on the outside wall and does not span like an interior joist, except possibly over a small window.

There might be a problem with local terminology.

Old 10-09-06, 10:20 AM
Join Date: Dec 2005
Location: massachusetts
Posts: 66
Upvotes: 0
Received 0 Upvotes on 0 Posts
Verdict on the duct holes in a rim joist?

So can you drill larger holes in an exterior facing rim joist to you can run duct thru them?

Followup: what is a good article or website that shows about framing house structures and how loads a taken by various parts of the framing?
THanks all
Old 10-09-06, 02:25 PM
Join Date: Mar 2006
Location: Great Barrington MA
Posts: 496
Upvotes: 0
Received 0 Upvotes on 0 Posts
I have done that procedure dozens of times with the blessing of the inspectors. In fact I don't recall it even being mentioned. The way I usually end up doing it without the huge expensive hole saw is to trace the vent fixture and then going a little outside the lines to allow room for the flex ducting, I drill a series of 3/4" holes around the circle with a ship auger bit. Then I connect the dots with a sawzall.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: