# Drilling 2x10 for 3 inch pipe



## Bob Mariani (Dec 1, 2008)

Be sure to drill the hole in the middle of the joist and within 24" of the bearing point. Strap with a steel strap that is fastened with teco nails. Strapping with lumber will do little good. Simpson makes a good one about 18" long


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## 47_47 (Sep 11, 2007)

Just a question... Can you drill a hole for a 3" pipe (3½" OD) in a 2x10 (1½"x 9¼")? Wouldn't this exceed the 1/3 rule? Or will these Simpson straps maintain the strength of the joist? This is for my own info.


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## Ron6519 (Mar 28, 2007)

47_47 said:


> Just a question... Can you drill a hole for a 3" pipe (3½" OD) in a 2x10 (1½"x 9¼")? Wouldn't this exceed the 1/3 rule? Or will these Simpson straps maintain the strength of the joist? This is for my own info.


Another solution would be to box the path to the stack pipe. Cut the joists out, structurally box out the space and use joist hangers to reattach the cut members. You also avoid small pieces of pipes and a series of couplings.
Ron


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## ponch37300 (Nov 27, 2007)

How would you drill all the holes in the center if you need to have a slope for the drain? Just curious.


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## jaros bros. (Jan 16, 2009)

You're probably going to end up running your pipe underneath the joists.

Josh Jaros


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## Bob Mariani (Dec 1, 2008)

All good posts, but we need to know more.... What distance are you going through the joists? Yes 3 1/2" would be okay. Boxing would work for only a short distance. Anything longer than two joists and you should plan on running below the joists and making a soffit.


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## handyflyer (Jan 12, 2007)

The run is going to be 8 feet. Boxing out the run is not a practical option. The floor under bathroom is under our kitchen.


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## handyflyer (Jan 12, 2007)

Box out for that long of a run?? Is that allowed per code?? I don't know.


Ron6519 said:


> Another solution would be to box the path to the stack pipe. Cut the joists out, structurally box out the space and use joist hangers to reattach the cut members. You also avoid small pieces of pipes and a series of couplings.
> Ron


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## Bob Mariani (Dec 1, 2008)

no, you cannot box it. Run it below the joists. you need 1/8" per foot slope. You may have enough to drill it. Use Simpson straps to reinforce each joist. You also need a steel plate when the pipe is closer than 1 1/4" in.


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## jcalvin (Feb 6, 2008)

Won't fly by the man in NC. Remember the 1/3 rule. You could get by with one joist, but the slope is the show stopper. If your slope is 1/8 per foot, sounds like a lot to for a drain but I'm not a plumber, then at the end of the 8 foot run you will have to have a 1 inch drop. That will exceed the 1/3 rule. Besides, if your house is already finished, how are you going to put a non-coupled piece of pipe in that length. Sounds like boxing is your only alternitive.


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## Michael Thomas (Jan 27, 2008)

Real word, those holes rarely get drilled exactly where you plan them to go, either - mess up, then you have enlarge one or more holes to maintain slope... you _could_ sister the joists, but the modification needs to be engineered, when I researched this a while back (as the result of a similar situation at a home inspection) I found this discussion informative: http://www.iccsafe.org/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=10;t=001699 with regard to the problems this sort of joist boring can create for a builder, contractor or homeowner.


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## handyflyer (Jan 12, 2007)

Like that pic.


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## RippySkippy (Feb 9, 2007)

Michael Thomas said:


> Real word, those holes rarely get drilled exactly where you plan them to go, either - mess up, then you have enlarge one or more holes to maintain slope... you _could_ sister the joists, but the modification needs to be engineered, when I researched this a while back (as the result of a similar situation at a home inspection) I found this discussion informative: http://www.iccsafe.org/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=10;t=001699 with regard to the problems this sort of joist boring can create for a builder, contractor or homeowner.



Great read....thanks.


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