Help with bathroom reno: toilet drain routing

[Pardner]

I recently purchased a house that was being used as an office. Previous owner removed the bath tub, but assured me there was one there at one time. I am trying to do the majority of the work myself; not my fisrt bathroom but far from a professional.

My first project was to remove the drywall under the bathroom and inspect the existing plumping and to my horror, the floor joists in the second floor run perpendicular to the floor joists in the first floor (opposite of what I expected).

So, the bathroom is on the second floor, it is a 60"x74" with a toilet and a sink:
https://drive.google.com/file/d/0B3Vhk3HHFW2oWU1VbjBod0JWakk/view?usp=sharing

I would like to shift the sink and the toilet to make room for the tub:
https://drive.google.com/file/d/0B3Vhk3HHFW2ob1h6dHpzWWdXQUU/view?usp=sharing

Under the bathroom, there is a structural wall and 2x8 floor joist running North/South. The toilet drain runs along one of the floor joists, then snakes behind one of the split joists.:
https://drive.google.com/file/d/0B3Vhk3HHFW2oWkdfUWY0UmU4TGs/view?usp=sharing

So now if I shift the toilet over 32" to make room for the tub... I have nowhere to run the drain!
https://drive.google.com/file/d/0B3Vhk3HHFW2oQUV0WGtOZXltZEE/view?usp=sharing

I am guessing its not possible to run a 3" drain through a double top-plate structural wall, but I wanted to present that idea. I was planning on putting in another floor joists in the 25" gap. Run the toilet drain down through the structural wall (through the double top plate). Nailing a stup strap on either side of the top plate where the drain cuts through the top plate. Add stud directly under the new floor joist.

Now, I have not started cutting/hacking anything. Only the drywall in the 1st floor ceiling is down. I was hoping to get some opinions on how/where to run the toilet drain. Please don't answer "call a professional contractor/plumber/engineer" I wanted to get some opinions and educate myself before I talk to the pros.

Thank you very much for reading my post... more thanks for input!

 

[Terry]

So 30" for the tub, 30" for the toilet and that leaves you 14" for the lav.
When you sit on a toilet, you will have arms attached to your shoulders. Those arms have to go somewhere. That's why building code wants 15" to center to the next item. Normally with three fixtures, it would be a room at least 84 long, if not 90".
Even the old bathrooms in the 1920's gave you 84" to work with, and I thought those were tight.

 

[Sponsor]

 

[Terry]

I am guessing its not possible to run a 3" drain through a double top-plate structural wall, but I wanted to present that idea. I was planning on putting in another floor joists in the 25" gap. Run the toilet drain down through the structural wall (through the double top plate). Nailing a stup strap on either side of the top plate where the drain cuts through the top plate. Add stud directly under the new floor joist.

Adding a stud below the joist to carry the weight is a good idea. A 3" pipe is 3.5" OD, or close to that. Normally you wind up cutting the two plates for a 3", or drill it, which is kind of the same since the hole takes up the entire stud anyway.

 

[Pardner]

Adding a stud below the joist to carry the weight is a good idea. A 3" pipe is 3.5" OD, or close to that. Normally you wind up cutting the two plates for a 3", or drill it, which is kind of the same since the hole takes up the entire stud anyway.

So something like this: http://www.homeownersnetwork.com/wp-content/uploads/2013/10/R602.6-top-plate-notch.jpg
But a 3" drain will take up the entire plate. Strap on both sides and a new joint to help support the old 24" center joists.

Even the old bathrooms in the 1920's gave you 84" to work with, and I thought those were tight.

My last two apartments we 60x74... That's where I got the idea that I could do this layout rather than punch out a wall.

Thank you for your input. Pard

 

[Scott D (CA)]

In your predicament, I would suggest you have a GC who specializes in remodels (along with his plumber) come by and take a look. He can give you options that are code compliant.

 

[Dj2]

Tub 32"
toilet 30" (15" times 2)
So far you got 62"
How can you squeeze a sink into the remaining 12"? (A wall mounted corner sink without cabinet is 15"-16").

Yes, you can get a plumber, see what he suggests. And yes, you will need to do it to code.

 

[hj]

Your mistake is that you figured 14" to the tub drain, but NOT 30 inches for the tub itself.