Joist Badly notched - need suggestions

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Slugger740

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Well, I am renovating my master bathroom, but next door to the master bath is a hallway bathroom (toilet, sink, tub). After opening the ceiling I have found some pretty extreme notching of the joist directly under the hall bath toilet (5" x 5" notch in a 2x10). There is also a 2" drain line about 9" away. The notch is from the original construction of the house.

There is absolutely no room to move the toilet in any direction that would help.
As you can see from the photos, the centerline of the toilet flange is approx 1.25" past the side of the notched joist.
There are metal reinforcers available (https://joistrepair.com/) but they are not designed to handle a notch this big.

I thought about chopping out a section of the joist and boxing off the toilet area with cross supports to the joists on either side, but the joist to the master bath side has been notched pretty well itself for vent/drain line (another item that can't move). Because of this, I will be sistering a 2x8 to the side of that joist for added strength, but I'm not sure transferring more load to this joist is a good idea.

My remaining thought is to leave the joist as it is, but add a new joist halfway into the next bay (further under the toilet). I should mention that the DWV line crosses through 2 bays before it turns so there is no bend in the DWV line in the next bay. The plan would be to use one of the metal reinforcement plates from JoistRepair to reinforce the 3" DWV hole in the new joist. The issue I have is the nearby 2" drain line. Will this hole compromise structure?

Thanks
Roger

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Slugger740

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I should add that the joists span is 12' and the notch for the toilet is about 3' from the end of the joist.
 

wwhitney

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Since your span is only 12', I'd check the allowable span tables in the IRC (you need to find a species and grade stamp on the joists) to see if a 2x8 is actually sufficient for this particular span.


If so, you could install a joistrepair 2x8 notch reinforcer around your notch and likely have an adequate repair. [A ripped 2x10 may be a worse grade that it was originally, but otherwise your 2x10 notched 5" deep is at least as strong as a 2x8 notched 3" deep.] But if the 3" WC drain is going through other joists in the still enclosed ceiling area, you should put hole reinforcers on those, since the prescriptive limit on hole size in a 2x10 is less than the OD of a 3" Sch 40 pipe.

On the joist where you show a possible 2x8 reinforcement, is that joist doubled for some other reason? If not, it's likely a reinforcement for the notch. The 2x8 alongside would be fine, or another notch reinforcer, or possibly nothing. [E.g. if a 2x8 is adequate for the span, it could be notched 7.25" / 6 to leave 6" of joist depth, and you have over 6" of joist depth at the notch. It's a bit more complicated than that, but the joist is also doubled, so doing nothing is within the ballpark.]

But if it is doubled due to some additional load on that joist, then the notch is more of a problem.

Cheers, Wayne
 

Slugger740

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Since your span is only 12', I'd check the allowable span tables in the IRC (you need to find a species and grade stamp on the joists) to see if a 2x8 is actually sufficient for this particular span.


If so, you could install a joistrepair 2x8 notch reinforcer around your notch and likely have an adequate repair. [A ripped 2x10 may be a worse grade that it was originally, but otherwise your 2x10 notched 5" deep is at least as strong as a 2x8 notched 3" deep.] But if the 3" WC drain is going through other joists in the still enclosed ceiling area, you should put hole reinforcers on those, since the prescriptive limit on hole size in a 2x10 is less than the OD of a 3" Sch 40 pipe.

On the joist where you show a possible 2x8 reinforcement, is that joist doubled for some other reason? If not, it's likely a reinforcement for the notch. The 2x8 alongside would be fine, or another notch reinforcer, or possibly nothing. [E.g. if a 2x8 is adequate for the span, it could be notched 7.25" / 6 to leave 6" of joist depth, and you have over 6" of joist depth at the notch. It's a bit more complicated than that, but the joist is also doubled, so doing nothing is within the ballpark.]

But if it is doubled due to some additional load on that joist, then the notch is more of a problem.

Cheers, Wayne
Hi Wayne,
Sorry for the slow response but got buried in regular work.

Your thought about the 2x8 schedule for the deeply notched joist is a really good one. I will definitely check it out to see if it will work. And yes, I will be using the reinforcers wherever the 3" pipes go through joists. I think I'm in for about $500 worth of reinforcers at this point. But it's cheap insurance compared to structural failures down the road.

On the doubled joist, it is supporting a wall of the bathroom, but it is not a structural wall as there is no wall below it and the attic joists run all the way out to the outer wall. So I think you are right that they doubled it because of the notch. Is odd they didn't do that with the one with the even bigger notch (but no accounting for logic when houses are being built). But it has survived 30 years without failing so far.

I will sister it with the 2x8 anyway as it will also provide a fastening point for the edge of my new subfloor above. I'm perfectly fine with over engineering something.


One question: I'm not moving that toilet where the deep notch is (it's actually in a different bathroom than the one I am renovating). It obviously passed inspection when the house was built 30 years ago... so, is it likely the inspector will flag it and force a repair (assuming I haven't already done so)?

many thanks
Roger
 
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