Hello - I am in the process of a major bathroom remodel. The bathroom is almost exactly 10X10 and I am swapping the shower and toilet locations (they are currently in opposite corners of the room). Draining/Venting the shower will not be an issue as I can tap into the same 2 inch drain pipe. The harder part is the toilet drain. I can tap into where the 4 inch pipe goes down through the floor, but then I need to traverse aout 8 feet, then one elbo, and traverse another 6 feet to terminate at the new location of the toilet. My qyestion is, will this loner run cause issues. I know I want to minimize elbos (so I will only use one) but will the long run cause a problem. Is there a specific drop per foot of pipe I need to maintain? (i.e. for every 1 foot of travel, drop one inch, etc).

Thanks,
Rob

You really want a vertical drop from the toilet to drain pipe. I seriously doubt that you could run what would basically be a horizontal pipe without back up problems. I feel that you would have to move the main pipe itself to fit under the toilet. Even if you did it your way wouldn't you have to remove the floor and subfloor? That is just as much trouble as a major plumbing job. No offense, but this is a job you want a professional to do. If you don't know what your getting in to you can really screw it up.

Hi Rob,

The slope will be 1/4" to the foot. I would much rather see you use a DWV Sweep rather then a elbo. I assume you're picking up the toilet with a closet bend. I can see no major problems with the longer run if you have enough fall.
Regards, Tom

Yes - I will need to rip up the floor and subfloor (floor is alread up - it was old carpet - I will be tiling). Subfloor is also now up where the toilet and shower will be. At 1/4 inch per foot of travel, I should only need about 8 inches, which should be no problem since I have trusses between the floors and not floor joists. As for DWV Sweep 90 degree, I assume the advantage over an elbow is the radius is larger, correct?

As for going from the new toilet location directly down through the wall, that is impossible as the place I am moving the toilet to does not have a wall under it to hold a 4 inche waste pipe.

Thanks for the answers!
Rob

I seem to be missing something here - if you're running 14 feet of toilet drainpipe before you get to where you would like it to drain (and, I'm assuming, to vent) won't you be exceeding the "critical distance" for venting (which I think is 6 feet)? Or will the toilet have a separate vent pipe right near it that the shower used to use?

This problem depends on whether you are going to get a permit or not. The way you described that you were goint to do it will work with only one minor problem and that being that when your commode flushes it might make a little
Extra noise right at the end of the flush. I am sure that this way would not pass inspection. But who know except me and you and I am not going to tell.

Thanks for all the posts. I was going to ask about how far from a pee-trap (or toilet) a vent needs to be. I was considering venting at the end of the 14 foot run, however it now seems that this may not be too code. I certainly can vent within a foot of the toilet. As per the comment about the toilet being a bit louder at the end of the flush, is this a function of how far away the vent is from the toilet?

Thains!
Rob

Hi Rob,

The most distance allowed between trap and vent on a 4" line is 10 feet.
This means to stay within code the vent can be located anywhere in the 10 foot limit. You are 4 feet over that limit. However If the job will not be inspected I can foresee no difficulty overlooking those 4 feet. If you did pull a permit click on back and I'll give you instructions on cutting in a 4X2" wye on a 45 degree angle,( the 45 degree angle is so the vent won't be affected by the discharge) into the toilets drain line. I don't know what letmetellu meant by," when your commode flushes it might make a little
extra noise right at the end of the flush." There's always a little "rush" at the end of every flush. ( Sounds like a song title doesn't it?) Cheers, Tom

Hey Tom - thanks for the post. I just measured the circumference of the toilet waste line, and using simple trig, the outter diameter is less than 4 inches. In addition, the markings on the pipes say 3 inches - does this make sense. The house was built in 88, and I would imagine it must have been built to code (I am not the original owner by the way, so this is just an assumption). The bathroom on the other side of the wall also has the same 3 inche waste pipe for the toilet there. So I don't imagine I will be able to run a 4 inch waste pipe from the new toilet location like I originally thought. Do you see this as an issue? Do you think it would now be a bad idea to run that length of run before connecting to the "down spout"? You had mentioned in an earlier post that it was 1/4 inch drop per foot of travel. I'm surprised that number is so small. In your experience, that drop per foot does not result in the pipe getting clogged with solid waste? That is my major concern. I'd hate to have to snake the lines every week ;) As for helping me with inserting a y connection to vent the toilet, that would be much appreciated. I don't imagine I will pull permits, however I wouls still like to do the job legit, mostly to prove to myself that I can.

One more question - I am defintely comfortable with waste pipe work as well as sweating pipes, and have plummed in a new shower into existing cast iron preexisting waste lines in a previous house. I have no problems tearing up subfloors, after all, it's just nails and glue. So should I continue to be brave here, or am I being over confident in my abilities with a job like this?

Thanks tom!
Rob

OK Rob,

On a 3" drain the distance drops to 6 feet. Let's err on the side of caution. You say that there's no problem in installing a vent a foot or so downstream from the closet bend? Do the vent take off like this. Install a 3X2" wye on a 45 degree angle with the branch looking back at the closet bend, this means install the wye so that the wye will drain into the toilets drain and not the other way around. You may now pipe the 2" vent out the roof or up into the attic where it will revent back into the main roof vent. As far as being "over confident" don't sweat it. You sound like you have the experience and confidence to pull it off and I can walk you through any rough spots. Besides this will be great training in case you ever want to enter the trade. Your concerns about the ammount of fall are needless. The fall can be between 1/8" and 1/4" to the foot. Too little fall and the water won't carry the solids away. Too much fall and the water runs so fast it drops the solids. That's how it works. Regards, Tom

Thanks for all your help Tom - your description as to how to vent the toilet was exactly what I came up with in my trip to home depot that I just came back from. Should be a snap. And since I can fall 1/8 to 1/4 inch per foot, without worry, I should have no issue with the waste line. In fact, I think I'll go pull the rest of the sub floor in strategic points once I submit this post.

Thanks again! I'll be sure to drop a line here when I'm done (or when I get stuck, whichever comes sooner :D

Rob

Hey all - I thought of another question - how high should I put the closet flange. Should the top be level with where the new floor should be? For example, I will be adding 1/4 inch of backerboard and then tile on top of that (this, over the subfloor which is 5/8 plywood), so should the top of the closet flange be level with the expected top of the tile, or even higher.

Thanks,
Rob

When installing the piping, the toilet drain pipe should be sticking out at least 2 inches from the floor. After you pressure-test the system (or, if you plan on skipping the test, then immediately) cut the pipe flush with the subfloor and install the flange. (Source: Black and Decker "The Complete Guide to Home Plumbing")

The funny thing is, though, that the pictures seem to show the flange resting on the finished floor. Maybe the pipe actually ends lower than the finished floor, and the flange continues it for the last half-inch (or whatever); or maybe the book is wrong...

For now, you should definitely install the pipe sticking out 2" as mentioned above. Just double-check with speedball1 or labman before you do the final cut. Either way, my information should be enough to get you started (until you hear from them).

Palm,

"When installing the piping, the toilet drain pipe should be sticking out at least 2 inches from the floor. After you pressure-test the system (or, if you plan on skipping the test, then immediately) cut the pipe flush with the subfloor and install the flange. (Source: Black and Decker "The Complete Guide to Home Plumbing")
The funny thing is, though, that the pictures seem to show the flange resting on the finished floor. Maybe the pipe actually ends lower than the finished floor, and the flange continues it for the last half-inch (or whatever); or maybe the book is wrong."

Black and Decker advise you to recess the closet flange? Not any new construction I've ever worked in. When a plumber arrives to trim out a new job, (install the fixtures) we find a bath room that has a finished tile floor, a closet stub up, a vanity cabinet waiting for a lavatory and a tub already installed. We glue on a closet flange level with the finished floor and cut the stubup back even with the flange, set and hook up the toilet and install and hook up the lavatory. That's how it goes on the West Coast of Florida

Regards, Tom

So Tom, to confirm, the bottom of the toilet flange will be resting on the final tiled floor, correct. As opposed to the top of the flange being level with the top of the tile floor, correct?

However for me to proceed now, I just leave the pipe (the one glued into the closet bend below the subfloor) a few inches above the plywood surface and then trim later on (after the tile floor is complete and the flange glued on).

Thanks,
Rob

Hey Rob,

It doesn't make that much difference. Closet flanges have but one purpose. And that's to secure the bowl to the floor. Since the bowl has a 4" horn on the discharge of the bowl that extends below the floor line you will have no leaks from either installing the flange on the subfloor or the finished floor. We just install them on the finished floor. Regards, Tom

The problem is, they're not very clear. Unlike their book about home wiring, their book about home plumbing makes a big mistake: they seem to assume that even though they show how to plumb a bathroom/kitchen, most people will not actually do it, and are only reading that section to understand how their existing/future kitchen/bathroom works.

I say this because their instructions can often be very vague. For example, "Plumbing a Bathroom" is divided into sections: how to install the toilet drain, how to install the shower drain, etc. However, when they finish the toilet drain section, they say you should leave a stub-up, and later, a flange will be installed, and then they move on to the shower drain section. But in the end, they don't actually go back and tell you how to install the flange; they just move right along - if you check the section called "Installing a Toilet", that section shows scenario where you have the tiles and flange already installed. They don't actually tell you HOW to install the flange. (I know it's not difficult to figure out, but it's a bit unsettling when they leave you hanging like that.) And it's not the only case where the author does that.

Hey Tom - would I be making a big mistake if I used an existing 1.5 inch vent to vent the toilet the way you describe above? I can run a 2 inch up into there attic and then over about 10 feet to tie in with the main roof vent, but it would be so much easier to tie into the 1.5 inch vent that is running through the wall already to vent the toilet.

Thanks,
Rob

I have been following this post and actually made the first comment. Flange this, flange that. Venting, drain, slope. I said it than and I'll say it again, this is really a job for a professional. I've installed my own toilets and I am loathe to think that I can't figure out how to do things myself, but this application has too many variables. After all your work and a month later then the toilet backs up or leaks from the flange you will have to call a plumber. He will have to undo all you have done and than start again. Are you really willing to take that chance? I know that I wouldn't and I'm no sissy.
BTW, the whole concept of the flange is that it is secured to the subfloor, accepts the seal from the wax (don't even think about using that pretaped crap) and prevents the toilet from rocking. So the answer is that it should be flush with the finished floor. Even a 1/8 inch too high will set it rocking, break the seal and possibly crack the bowl.

Good morning Rob,
While we prefer a 2" vent a 1 1/2" vent's acceptable if a 2"" vent presents difficulties in installing. What fixture is the existing 1 1/2" vent servicing?
Cheers Tom