Support for removed load bearing wall

[masraum]

This is related to my HVAC thread.

We have a 1/2 bath upstairs that's built for hobbits. We want to move it across the hall. Between the two locations there was a wall that separated 2 rooms. The wall was removed. The waste pipe for a toilet needs to run from the location of the new bathroom, across to the existing bathroom. The joists for the second floor are 2x6" and run the direction that the plumbing needs to run. The issue is that where the wall was, there is what looks like a 4x6 beam in the floor. To run the waste pipe would mean drilling a large hole through that beam. THe wall under the beam was removed years ago. Where the wall was, as far as I can tell, there are two vertical 2x4s that are stacked and parallel to the walls. They support two horizontal 2x4s that run under the 4x6 and are air gapped by about 3/4".

I'm thinking that if we wanted to cut a hole through the 4x6 for the waste pipe of the toilet, we'd need to beef up the supports where the wall was. I actually plan to put the wall back to turn the existing single long room back into 2 rooms. I was thinking of having a "window" in that wall that would allow a TV to be set somewhat into the wall. The window wouldn't be completely open, there would be drywall on one side and the other side would allow the TV to sit into the wall. I'd be gaining the depth of the framing. I was thinking that I could easily add a 4x6 at the top of the wall with plenty of support under it so that cutting a hole through the existing 4x6 wouldn't be an issue.

Granted, no one's thoughts on this matter would be considered binding, but I'm wondering what the educated guesses of the board are.

existing wall with extra supports in yellow and proposed location of hole in yellow.


This shows the location of the old toilet (top) and new toilet (bottom) and path of the waste pipe (brown). The two vertical red lines are the path of the joists that support the second floor. The blue rectangle is the 4x6 beam that is in the ceiling and would require a hole for the waste pipe to pass through. Under or approximately under the red line on the right is the location of a wall that runs the length of the house downstairs (long central hall). Where the waste pipe jogs right at the old toilet is approx where it goes down inside an interior wall (right side long, vertical red line). And yes, where the blue rectangle stops is as far as it runs. To the right of the right side red line, I can see all of the way to the other side of the house through the floor.


Proposed change to wall and supports. (this is very informal, not to scale, and just spitballing at this point. We are just trying to determine how feasible this is before we schedule the plumber to come out and rough in the plumbing.

[908/930]

Could you just add two 45 deg fittings and go around that support? So exit the toilet at 45deg then one 45 to point back in line with the trusses and a 45 at the far side to get back to your main stack. Also you will need to vent that drain pipe. Is there enough height for your slope in the pipe?

[masraum]

Originally Posted by 908/930

Could you just add two 45 deg fittings and go around that support? So exit the toilet at 45deg then one 45 to point back in line with the trusses and a 45 at the far side to get back to your main stack. Also you will need to vent that drain pipe. Is there enough height for your slope in the pipe?

I'm not sure if I don't get what you're saying or you aren't understanding my drawings (hard to believe as impressive as they are)

This is the old toilet (left), new toilet (right) and path of waste pipe (brown) that needs to go through the 4x6 beam (yellow).




There's a vent out of the roof near the existing toilet. The plumber (we had someone come out to discuss the feasibility and rough estimate) said that he would put a vent in near the new toilet. It was special. I think it may have been an "air admitance valve"

[908/930]

That is what I was picturing, was just thinking that if there is a clear path right beside that beam you could just go around it. Another possibility would be supporting the joists and replacing that wood with a steel I beam with the clearance hole cut into it. I would trust the steel over the wood with a large hole in it. You are going to add a vent to that pipe? If you intend to fully support under the 4x6 with a wall that should be fine.

[look 171]

Hosw big is that span and how thick are the floor joist?

[908/930]

You mention 2x6 joist, something to consider is a 4" long elbow is about 8" to the bottom then add your slope.

[Crowbob]

If there's no concrete and rebar involved you should be OK.

[dad911]

Is there a reason you cannot just drop a new drain line through a different 1st floor wall?

[rwest]

Air admittance valve may not meet code in your area; might want to check first.

[masraum]

Originally Posted by 908/930

That is what I was picturing, was just thinking that if there is a clear path right beside that beam you could just go around it. Another possibility would be supporting the joists and replacing that wood with a steel I beam with the clearance hole cut into it. I would trust the steel over the wood with a large hole in it. You are going to add a vent to that pipe? If you intend to fully support under the 4x6 with a wall that should be fine.

the big beam is perpendicular to all of the floor joists. To go around it, I'd have to go through a joist twice.

Originally Posted by look 171

Hosw big is that span and how thick are the floor joist?

floor joists are 2x6 and the span is 9'

Originally Posted by 908/930

You mention 2x6 joist, something to consider is a 4" long elbow is about 8" to the bottom then add your slope.

We discussed with the plumber putting the toilet on a small platform to raise it up high enough for the pipe to run within the space within the floor. Then we are going to drop the ceiling in one room by ~6" to ensure that there's enough space for the 1/4" to 1' drop.

Originally Posted by Crowbob

If there's no concrete and rebar involved you should be OK.

Nope, all wood.

Originally Posted by dad911

Is there a reason you cannot just drop a new drain line through a different 1st floor wall?

I'm pretty sure that would be a much bigger job. The reason that it works for the existing drain line is because it drops down under the stairs.

Originally Posted by rwest

Air admittance valve may not meet code in your area; might want to check first.

The plumber seems to think it is, but I'll confirm. If not, there's place for us to get a regular vent installed.

Thanks everyone.

[dad911]

In-wall tank can get the drain above the floor. Creative framing plus the additional pitch will get you over that beam. I've seen them used in concrete floor-condo construction to move toilets w/o moving floor drains/penetrations.

IMHO plumber is taking the easy way out with an AAV. We've used them in a basement, but on the second floor he should either cut in a new roof boot or tie into an existing vent. Minimally have him put the AAV in the accessible attic space and not a vent in the wall.

https://terrylove.com/forums/index.php?threads/toto-wall-hung-outlet-pipe-slope.69960/

[ben parrish]

The Studor Vent will work as the existing stack will stay in place. The AAV vent only opens when a vacuum happens but the drain line must also have a live vent to allow air to “push” ahead of the water. The toilet will not flush properly without a live vent.
How far is the new toilet from the old? If the drain line is 3”, you can go within 6’ and be within code...if a 4” drains line is installed, you are good up to 10’. Btw, the AAV valve mus not be buried in a wall and must be accessible for service and repair.

[ben parrish]

The 2x4’s with the “air gap” are not really that strong. To give the proper strength, sandwich a 3”4 strip of plywood between the 2x’s and glue and screw. This will give you a much sturdier support and a true beam.

[masraum]

Originally Posted by dad911

IMHO plumber is taking the easy way out with an AAV. We've used them in a basement, but on the second floor he should either cut in a new roof boot or tie into an existing vent. Minimally have him put the AAV in the accessible attic space and not a vent in the wall.

https://terrylove.com/forums/index.php?threads/toto-wall-hung-outlet-pipe-slope.69960/

I'll check out the other stuff that you're talking about.

We don't really want to have another perforation on the roof if we can get around it. It's on the front of the house and will be highly visible. Running the line around to the existing vent will also be a big run that'll likely be a pain in the rear. Yes, the AAV would be in accessible attic space.

Originally Posted by ben parrish

The Studor Vent will work as the existing stack will stay in place. The AAV vent only opens when a vacuum happens but the drain line must also have a live vent to allow air to “push” ahead of the water. The toilet will not flush properly without a live vent.
How far is the new toilet from the old? If the drain line is 3”, you can go within 6’ and be within code...if a 4” drains line is installed, you are good up to 10’. Btw, the AAV valve mus not be buried in a wall and must be accessible for service and repair.

Yes, there is a live vent at the existing toilet that I assume would stay in place, and yes, the line would be 3". I think the flange to flange distance between new and old toilets would be 18-19'.

Yep, the AAV would be in accessible attic space.

Originally Posted by ben parrish

The 2x4’s with the “air gap” are not really that strong. To give the proper strength, sandwich a 3”4 strip of plywood between the 2x’s and glue and screw. This will give you a much sturdier support and a true beam.

Yes, I was surprised to see the air gap in those 2x4s myself. I realized that our plan is to put the wall back in place, so I should be able to put a new reinforcement in that is sturdy, plus I'll have the wall there supporting the beam. I suspect the beam was added when the original wall was removed.

[javadog]

If you build a wall under the existing beam, there's no need to add another beam under it first.

Run the new toilet drain down through the new wall, not across the house.

[ben parrish]

You don’t need a new hole through the roof...if you have the wall opened, you can just run a new stack in the wall and through the top plate into the attic then tie into the stack that goes through the roof.

[masraum]

another view

[javadog]

You consider raising the ceiling in the existing bathroom? Wide dormer, with windows.

[masraum]

Originally Posted by javadog

You consider raising the ceiling in the existing bathroom? Wide dormer, with windows.

The ceiling in the existing bathroom is boards nailed to the underside of the beams that make up the roof framing. That bathroom is as tall as it can be without modifications to the roof of the house.

[island911]

A quick glance...

The top and bottom surfaces of the beam take the majority of the load.

A 2x6 will not likely be carrying a lot of load. I would use some steel nail-plates or similar to span the thin parts of the hole. That's it.