How do I add more support to this vertical main drain pipe?

[Mini Me]

The perforated brace support you see there is loose and ineffective. It is nailed on both sides to a joist that sits under that bottom wall plate. The pipe seems to rest on the piece of wood that is under the toilet tee and on a 4" flexible coupling installed downstairs see the second picture.

There is also a rather light shim that you can spot at the left side of the pipe where the pipe meets the bottom plate. I looked at that coupling and I am not sure if it compressed or not (seems to be a little bit, I can access it from time to time to check what it looks like (currently "dressed" by shelves that go up on both sides).


However, since I am doing work around the upper part which you can see in the first two pictures I am considering adding more or better support there. Ideally I should use a riser clamp, but as of now the pipe is already protruding out of the bottom plate of that wall at the bottom part, like 1/8" (you can see how the builder had to cut the wall plate to allow the pipe to align downstairs). Luckily I will have to add a two layers of drywall or cement board there when I close the wall, and I can do a cutout in the first layer at the bottom side to compensate for that.

Adding a riser clamp there will aggravate the misalignment problem with 1/8 or more. Toward the upper part the situation is better the pipe is now aligning with the studs and it correctly gets enclosed in the wall. Ideally I need a riser clamp that I can anchor on the studs somewhere above the venting tee that you see at the work lamp level. The other option would be to reinforce under the floor (replace the copper perforated strap or add some clamp there).

What hardware can be used for this? The problem gets more complicated if you consider that zinc or other metal to copper could lead to corrosion caused by different metals contact. Rubber could be used at the contact points.

I am considering something like below but I need recommendations on what materials to use for strapping (blue lines) I will have to add support for subfloor near the wall (orange filled in in the sketch) so I could strap to that and then add one more 2x4 under the toilet drain

 

[Reach4]

For your copper tee, how about a wooden prop, about 30 degree off of the vertical on the left pushing mostly up. On the right, a block on the right side of the tee, with shims for fine tuning, to provided a counter force that pushes left to prevent the tee from deflecting right.

 

[Sponsor]

 

[GReynolds929]

Replace the copper drain while you have it open and accessible. You will have to do it eventually, be best to do it now. What is with the wierd small flexible pipe vent getup?

 

[Mini Me]

For your copper tee, how about a wooden prop, about 30 degree off of the vertical on the left pushing mostly up. On the right, a block on the right side of the tee, with shims for fine tuning, to provided a counter force that pushes left to prevent the tee from deflecting right.

Yeah I am considering a similar idea, I just realized that the entire thing is also supported by the horizontal copper pipe that vents the sink and the shower drain (they both converge in that small pipe that you see its elbow to the left of the toilet drain


Something like in the picture below
The studs are 4.5" (2x5 nominal) and the pipe is 3" copper, so that leaves me exactly that much space to add a supporting 2x4 behind it. If I add that then the entire thing is going to be supported to the left by the horizontal pipe entering the stud to the left
and to the right and left by supplementary clamps like this

https://www.amazon.ca/Soimuk-Clamps-Stainless-Cushioned-Conduit/dp/B0CXSV5HHQ?th=1

The biggest challenge will be to secure the left side of that horizontal 2x4 as it goes behind a vent pipe (the tee you see to the left of the work lamp in the first picture. I do not have access from the left side of the stud to the left.

That part of the pipe that goes into the stud to the left is resting on the bottom of the hole so it plays a role in supporting the vertical pipe. Adding the horizontal 2x4 will reinforce the entire assembly and I can clamp there 2 or three of these rubber clamps I am buying from Amazon (linked above)

 

[Mini Me]

Replace the copper drain while you have it open and accessible. You will have to do it eventually, be best to do it now. What is with the wierd small flexible pipe vent getup?

That is a vent that comes from downstairs (older project I posted about here 4y ago) -I just could not find anything that fits behind that 3" pipe there and does not require me to cut the studs excessively (there is a kitchen on the the other side and I want that wall to be as solid as possible. The components used might not be the most standard one but everything is dry about the toilet drain level. The vertical smaller copper pipe used to vent a sink that was downstairs right below and which was removed so I reused the plumbing to reconnect the vent for downstairs
I already have a built is medicine cabinet in that wall that is removing like two studs there so I did not want to weaken the entire thing by drilling something that would accommodate 1.5" ABS piping so I just used some irrigation fittings , the flex pipe you see there I think it was intended for a washing machine (don't remember the exact purpose)

 

[Mini Me]

Replace the copper drain while you have it open and accessible. You will have to do it eventually, be best to do it now. What is with the wierd small flexible pipe vent getup?

why do you think I will have to replace it ? It is intact and in good shape
And If I do it what would you recommend ? transition to PVC using a flex coupling right there in that box ?

 

[wwhitney]

1) Figure out how to support the copper stack above the tee at the top of the picture (the one behind the work light).

2) Remove the copper stack between the tee where the water closet drain connects up to and including the tee where the vent connects. Remove also the vent riser to the left of it, as well as the crazy small diameter vent tube running behind the stack.

3) Inspect the remaining copper used for drainage for any pitting or degradation or other signs it will fail within your time horizon (i.e. sooner than you'd have to open up this wall again anyway). Replace as appropriate. Copper used for venting I expect is less like to degrade.

4) Add a new tee at the top of the picture for connecting the ABS vent on the right to the stack, with the side inlet pointed to the right. Rebuild the stack between the two tees. Reconnect the ABS vent.

4) Do not use any rubber couplings that not fully shielded. If you can see any of the rubber from the side (as opposed to the thickness of the rubber, visible at the ends), it's not the proper type of fitting to use above ground.

Cheers, Wayne