Take the 2-minute tour ×
Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

I need to move a toilet to the other side of room approx. 6 ft I will have to drill a 3.5 in hole for the waste line in 5 floor joist on the second floor. Can I double them and still drill the 3.5 in hole and be in compliance?

share|improve this question

2 Answers 2

You need to box off that floor joist. You can remove an section of the joist in the way. You then build a box connecting the ends of the cut off joist to adjacent joists with perpendicular ties of the same dimensions of lumber. 2X10's for example. These ties transfer the load to the adjacent joists and give you an opening for plumbing or duct work.

share|improve this answer

Not unless they are 2x12 floor joists and it goes exactly through the center. The maximum permissible boring in a floor joist is limited to 1/3 of the height of the joist (with a 2" minimum). See IBC 2308.8.2.

Sistering the joists would not effect this restriction, as it is an issue of the structural integrity of the framing member - not an issue of the required lumber dimension for a given span.

share|improve this answer
    
That's what I figured, I was hoping by doubling them it would work, I couldn't find a solution to this in the building code –  Joe m Mar 23 at 23:20
    
You run the pipe somewhere else (possibly straight down in a plumbing chase), you put in a pair of support beams below, you rethink moving the toilet, you sell the house and start from scratch elsewhere... –  Ecnerwal Mar 24 at 0:57

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.