Plumber overdrilled studs in partition wall

[DIYorBust]

So, on this project the plumber installed a 2 inch cast iron vent horizontally in a 2x4 wall. I had specified, and several times told him to use 1.5 inch pipe for this vent, which serves 2 lavs and a bathtub. The plumber was ultimately fired from the job by the GC. However the studs are drilled or notched up to 80-90%.

The GC proposes that we repair the wall by attaching .5" plywood on both sides. The wall needed to be thickened anyway to align with fixtures, so it doesn't really cost me any space. My concern is whether the wall will be rigid and secure enough for tile to be installed on it. It is a partition wall only and is non load bearing.

I think I would be within my rights to demand they redo the vent in 1.5". However, this would cost the GC more money and delay the job, plus he has really helped me out on many other problems, and it's not a situation where I'm looking to make him do more work than needed just because I can.

What do you think, should I accept this work, or will it give me a headache down the road?

Thanks,

DIY

 

[JohnCT]

If the only point of the 1.5" vent was to reduce the hole size in the 2X4 studs, then I don't know what difference it makes at this point if you go back to 1.5" vent: the damage to the studs is done.

I'm not a structural engineer but my gut says the wall will be fine and plenty stable for tile with .5" plywood glued and screwed directly to both sides of the 2X4 studs.

John

 

[Sponsor]

 

[wwhitney]

To be clear, this is not a load bearing wall? And you have a 2-3/8" diameter pipe in it, but it going to be furred out to 4" deep anyway?

If the pipe is pretty well centered in the 2x4 stud depth-wise, and the holes are say, 2-1/2", then they make stud shoes for reinforcing the studs in that situation. The basic model Simpson SS1.5 would be fine. The HSS2-SDS1.5 is beefier but probably not needed.

If the holes are quite off center towards the side that is getting furred out, then you should still be able to use stud shoes, you may just need to furr out under the stud shoe 1/4" or 1/2". If the holes are quite off center the other way, the SS1.5 would still fit, although I'd be a bit concerned about the lack of strength on the far side. Or you'd likely have 1-1/4" in front of the pipe after furring, so you could install flatwise 2x4 studs connected to each regular stud, relieving the thickness where it crosses the pipe as needed.

Cheers, Wayne

 

[Jeff H Young]

Id be good with 1/2 ply both sides . not concerned at all

 

[hj]

I have done what he did and NEVER laminated plywood to the studs.

 

[Terry]

Only a few times did I ever use 1.5" cast iron no-hub. I did install lot's of 2"

 

[Jadnashua]

When the pipe is that close to the outer surface, they want you to provide a nailing plate...a saddle would be better as it's longer and would attach above and below the hole there.

 

[Jeff H Young]

Only a few times did I ever use 1.5" cast iron no-hub. I did install lot's of 2"

Right on Terry ! I missed it was commercial cast iron vent. Of cource we go all 2 inch. I have used 1 1/2" on resedential pretty sure its more expensive than 2 we dont use 1 1/2" almost ever.
In addition I agree with HJ about the plywood . but anything to keep the owner from whining. get it done itll be ok

 

[DIYorBust]

Wow thanks for all the responses. First to be clear, I am the property owner, not the contractor. But I want to be fair to the contractors, and not make them redo work that will be fine. The wall is clearly inadequate in it's current condition. Some studs were notched out to 80 or 90%, and they move easily. The project is residential. I discussed doing the vents in PVC and the drains in CI but the price difference was not that much and the plumber did not want to do it. The code in NYC only recently allows PVC in this type of building, and I believe the firestopping makes it a pain.

We are certain the wall is not bearing. It is a new partition wall with no new loads being added above. If it were load bearing, I would have the structural engineer supply a solution, but most likely it would not be possible to drill the entire wall even for 1.5" pipe.

To be clear, the point of changing to 1.5 inch CI pipe would be to replace the studs. My concern is that the wall will be tiled, and I don't want someone to bump the wall and have all the grout fall out.

Also I should say, plumber was not fired for only using 2" in this wall against my specs, he also made other errors, such as creating and island loop with no vent connection, installing zero cleanouts in the entire building(and cleanouts are needed), and being unable to arrive timely each day and complete the job. Plus many other errors.

@Terry Generally we are using 2 inch+ CI everywhere. Except here I specified 1.5 inch CI because it fits in a 2x4 wall without overdrilling the studs. The plumber did say 1.5" was more expensive, but in this case I supplied the material and it was not more expensive, in fact it was cheaper at my supplier. I will say, 1.5" CI is nice to work with, because it is lighter and more forgiving in tight spaces. However I think these benefits don't outweigh the convenience of having fewer types fittings and and pipes at the site, assuming the job can be done in 2 inch. But if you have to go horizontally in a 2x4 wall to vent less than 8 fixtures units, it seems like a decent option to go with the 1.5".

But based on the help I got here, I'll allow the plywood repair. I'll have the GC guarantee the repair will be rigid enough for tile, but if it's fine it's fine. No reason to make a big hassle.

 

[Jeff H Young]

Now Im flip flopping. First off Id put 1 1/2 if it was plastic and if code allows plstic thats the way Id do it. smaller pipe of cource easier to work with just like you said though easier not to throw more fittings into mix.
So the vent issue is least of worry or actually no worry . Thanks for comment on price differance Ill have to review that no question at times especialy resedential 1/1/2 can be easier to work with but I usually just trudge through no big.
Now you need adress the other code violations good luck on project hope its back on track.

 

[wwhitney]

Ah, I missed a couple key details in your OP, the 80-90% (making stud shoes not a good option) and the plywood on both sides, sorry about that.

Not sure what to think of the double plywood. I would think it is still worth reinforcing each stud beforehand. The best way would depend on the conditions, a picture would help. Could be anywhere from replacing the studs (intalling new predrilled studs at the same time as the pipe segment) to attaching metal reinforcement on each side of the side on each stud.

Cheers, Wayne

 

[DIYorBust]

Now Im flip flopping. First off Id put 1 1/2 if it was plastic and if code allows plstic thats the way Id do it. smaller pipe of cource easier to work with just like you said though easier not to throw more fittings into mix.
So the vent issue is least of worry or actually no worry . Thanks for comment on price differance Ill have to review that no question at times especialy resedential 1/1/2 can be easier to work with but I usually just trudge through no big.
Now you need adress the other code violations good luck on project hope its back on track.

Thanks man! The plastic vents would be cheaper and easier, but not significantly for this short run. I think the the problems come with installing fire collars where they go through the apts, and dealing with potential inspection issues around that. I think the violations will be pretty easy to fix as the GC is bringing another plumber. What I'm seeing though, is inspectors are focused on one or two issues, usually around gas or other safety requirements, probably won't fail the inspection because there's no cleanout. But then what do I do if I need a cleanout later? Inspection is important obviously, but there are some practical requirements too.

 

[DIYorBust]

Ah, I missed a couple key details in your OP, the 80-90% (making stud shoes not a good option) and the plywood on both sides, sorry about that.

Not sure what to think of the double plywood. I would think it is still worth reinforcing each stud beforehand. The best way would depend on the conditions, a picture would help. Could be anywhere from replacing the studs (intalling new predrilled studs at the same time as the pipe segment) to attaching metal reinforcement on each side of the side on each stud.

Cheers, Wayne

Do yo think putting an angle iron on the notch side would do the job? If we install new predrilled studs, probably we should replace the pipe with 1.5".

 

[Jeff H Young]

Thanks man! The plastic vents would be cheaper and easier, but not significantly for this short run. I think the the problems come with installing fire collars where they go through the apts, and dealing with potential inspection issues around that. I think the violations will be pretty easy to fix as the GC is bringing another plumber. What I'm seeing though, is inspectors are focused on one or two issues, usually around gas or other safety requirements, probably won't fail the inspection because there's no cleanout. But then what do I do if I need a cleanout later? Inspection is important obviously, but there are some practical requirements too.

Mostly our plumbing codes are minimum requirements . sometimes a clean out is unsightly but many times its pure laziness to adhere. of cource we have cleanouts that dont get used for 50 years as well.

 

[wwhitney]

But then what do I do if I need a cleanout later?

If you have the pipes well documented, then you know where you want the cleanout to be. So you cut out a rectangle of drywall, center to center on the studs, of sufficient height. Then you cut out the right height of cast iron, at least temporarily supporting the upper portion, and add the tee fitting and two no hubs. Then you patch the drywall.

Do yo think putting an angle iron on the notch side would do the job? If we install new predrilled studs, probably we should replace the pipe with 1.5".

Now that I look at it again, the HSS2-SDS1.5 might be enough on its own, if the notch is only 2-1/2" high. An alternative:

If every damaged stud is notched, then you should be able to slip out the pipe by disconnecting some no-hub couplings. Then you can cut some 36" lengths of stud as scabs, predrill each scab dead center at 2-1/2", and reinstall the pipe with the scabs interleaved with the studs. Then use (12) 3" structural screws (e.g. Simpson SDS screws) to attach each scab to its stud, half above and half below the pipe.

Or for belt and suspenders, scabs and HSS2-2-SDS3 for double studs. Which uses (12) SDS screws, so I think you'd only need (6) - (8) more above and below the HSS2-2.

Cheers, Wayne

 

[DIYorBust]

I could add a cleanout when the time comes, but I think it's reasonable to have at least one cleanout in a 60 foot stack.

I'll see what you're saying wayne, and it sounds like it's possible to make a repair, so I'll mention this idea to the GC, but probably leave it up to him to select the repair method as long as he guarantees the performance of the wall. Thank you.

 

[DIYorBust]

Here is a sample of the type of work I am describing. We have 3 such walls. Repairs have begun on the far wall.

 

[wwhitney]

That's some definite butchery.

In the foreground, the ones that aren't notched, I think the HSS2-SDS1.5 alone would suffice. You could consider scabbing the notcheds studs with a piece from bottom plate to mid height blocking, notching it on the opposite side, and then using the HSS2-2-SDS3.

Let us know what solution you end up with.

Cheers, Wayne

 

[Terry H]

It’s important no doubt but if it isn’t on a load bearing wall it makes it not so bad. Often times there is no way around it and you just center them up the best that you can.

On things like LVLs and things that are really important to the structure they have rules like no more than 10% notching and it has to be in the center. So for a 18” LVL you can only get just under 2 inches. Now I’m not fluent with that portion of the code but have had to deal with it.

I think you’ll be fine.

 

[Jeff H Young]

Saw your picture . Ok not great but non bearing . forget about it