Proper way to add drain for a basement bathroom

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Old 10-20-09, 04:02 PM
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Proper way to add drain for a basement bathroom

Hello all,

I am planning on adding a bathroom to my basement. The location of the new bathroom is right above the stub of an old sink drain (3" pipe). Estimates from plumbers are in the $2k - $4k range.

There is an existing vent in the basement that I can tie into but it is about 10 feet away from the bathroom location. I have attached a diagram showing the exisitng drains (blue), existing vent(red) and my future handiwork(green).

Is my plan safe? I am sure something has to be wrong with it - I hope someone will point out what! :-)

Thanks!
 
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Old 10-20-09, 08:22 PM
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Overall, your plan is reasonable... but the devil is in the details.

I'm sure much of that $2-4K cost is for cutting, breaking, and digging the concrete.

You may also need to consider your vents. I'm not sure if you can wet vent the shower through the toilet. The shower may need it's own vent (at least up, but then can be back-vented into the other vents). But I'm far from a piping design expert, so wait until others chime in.

You also need to be careful what areas you use sanitary tees and wyes (having learned the hard way).

Good luck!
 
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Old 10-20-09, 09:00 PM
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Zorfdt,

Thanks for the info. I have never heard of 'sanitary' tees and wyes before. This will give me something to read up on tonight.

Some of the estimates I got came with the offer of cutting the price in half if I break up the concrete myself. I have no problem doing that, but I figure that if I'm gonna do the hard labor party myself I might as well try my hand at the whole thing:-).
 
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Old 10-21-09, 04:08 PM
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Bathroom Rough-In

Originally Posted by jasonk823 View Post
Hello all,

I am planning on adding a bathroom to my basement. The location of the new bathroom is right above the stub of an old sink drain (3" pipe). Estimates from plumbers are in the $2k - $4k range.

There is an existing vent in the basement that I can tie into but it is about 10 feet away from the bathroom location. I have attached a diagram showing the exisitng drains (blue), existing vent(red) and my future handiwork(green).

Is my plan safe? I am sure something has to be wrong with it - I hope someone will point out what! :-)

Thanks!
What I would do with your plan is to run a 3in. 45 or sweep at your tie-in, I would then add a 3x2in. wye, out of the 2in. branch I would add a 2in. wye, out of the end I would install my shower trap, out of the 2in.wye branch you would run a 2in. vent in the wall or an accessible location (since this is a flat vent it must have a clean-out above the floor)

To continue your line I would run the 3in. to the toilet area, run a 45 toward the toilet, add a 3x3x2 wye, out the end of the wye hook up your toilet, out of the 2in. branch pick up your sink, that will wet vent your toilet (the vent has to be run 2in. all the way to your tie-in) this layout should conform to the UPC, hope it helps.
 
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Old 10-27-09, 09:53 AM
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Originally Posted by shacko View Post
What I would do with your plan is to run a 3in. 45 or sweep at your tie-in, I would then add a 3x2in. wye, out of the 2in. branch I would add a 2in. wye, out of the end I would install my shower trap, out of the 2in.wye branch you would run a 2in. vent in the wall or an accessible location (since this is a flat vent it must have a clean-out above the floor)

To continue your line I would run the 3in. to the toilet area, run a 45 toward the toilet, add a 3x3x2 wye, out the end of the wye hook up your toilet, out of the 2in. branch pick up your sink, that will wet vent your toilet (the vent has to be run 2in. all the way to your tie-in) this layout should conform to the UPC, hope it helps.
Thanks for the great information. It's a lot to digest but I have been going over it and I THINK I have it all figured out now.

Basically, this is what I take away from it:

main drain -> branch -> shower -> vent in wall, with access
main drain -> branch -> toilet -> sink -> tie into existing vent

I appreciate the detailed instructions you gave - having the drain sizes will really help. I do have another question -

What is the minimum pitch of the drain? ie 3" every 1', etc? What about the minimum pitch for a vent? I will have to run across an expanse of ceiling between joists to get to my existing vent. I have about 10' of ceiling to cover and about 10" of joist height. Can that work?
 
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Old 10-27-09, 11:03 AM
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The minimum slope for the drain is 1/4" per ft. The vent is vertical of course, but can be level in spots if need be. The only thing it can't do is have any areas that run downhill between the drain and the roof outlet.
 
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Old 10-27-09, 02:16 PM
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Originally Posted by lefty View Post
The only thing it can't do is have any areas that run downhill between the drain and the roof outlet.
Ah, that makes sense - I guess you could get moisture buildup in there and eventually it could form a trap.

How do I tap into my existing drain? After I pull up the concrete, do I just cut out a chunk of the existing drain equivilant in size to the PVC tie-in and attach it with those black rubber belts? I have seen them used before but always on vertical runs. No idea what they are called :-(

Is it OK to use those in a horizontal area that will be covered with concrete? Or is there a different way to do it in situations like this?

Thanks!
 
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Old 10-27-09, 05:48 PM
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That looks fine mostly. However, you might as well vent each individually up to the red. That is the right way to do it.

I'm doing something like this now in my basement but I have no venting above to tap. I have checked NY code and am actually allowed to vent my entire new bathroom branch to an air admittance valve, which I will be doing.

I started cutting into the concrete tonight. Considering you are right over your existing drain (like I am) unless you really are made of money you should do this yourself. I've never done it before but it's coming along as I expected it would based on what I've read, not terribly difficult really. I even went cheap and didn't rent a jackhammer, just a couple of picks and a 12 lb sledge hammer. That thing is a beast Harbor freight, $25.

"I have no problem doing that, but I figure that if I'm gonna do the hard labor party myself I might as well try my hand at the whole thing:-)."

ABSOLUTELY. The plumbing is the easy part, at least labor-wise. You do need the correct drainage, minimum pipe sizes, and some venting approach, but if you're going to bust the concrete by then you've read enough to do this yourself and the parts are quite cheap.

"do I just cut out a chunk of the existing drain equivilant in size to the PVC tie-in and attach it with those black rubber belts? I have seen them used before but always on vertical runs. No idea what they are called :-("

Funny you ask. I JUST posted a thread specifically asking this question. Like 10 minutes ago.

I am using 3" pipe for my toilet. That's standard. 2" for the shower and sink is what you use. Venting I believe is 2" to be safe but I'm not positive as my venting situation is a bit diff from yours.

When you cut into the concrete the dust from the scoring that you'll get with the saw is to be avoided. I bought a $27 respirator from home depot, it traps even lead and asbestos, apparently. I also had my shop vac right up against my circular saw as it was cutting sucking in concrete dust. I put a hepa filter in there (I bought a ridgid shop vac from home depot and hepa is its level 3 filter. Level 2 is rated to handle concrete dust, though, but level 1 is not). Opened my window and had a huge fan moving air outside and turned my furnace off. Maybe this is all overkill, but at the least do have some kind of a mask while doing this and it is very dusty without the shop vac sucking it in. I don't think you need to score very deeply at all. Once you can dig a bit of a hole and get under the concrete with the spike-chisel you can easily hollow out underneath the rest of the concrete and then when you smash it with the sledge it will cave in. Buy your chisels from lowes--the ones at harbor freight are a bit rinky dinky, but the harbor freight (if you have one locally) sledge is fine and much cheaper than at home depot or lowes.
 
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Old 11-10-09, 01:47 PM
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Well, I marked where my drains needed to be and I dug up my floor... only to find that the existing drain was positioned slightly different than I initially thought.

I made a revised layout of how I think my new drains should be. Any advice anyone can give will be appreciated!



FYI, this is a view looking down on the drains. I felt that was obvious by my wife is standing over my shoulder insisting that I clarify that point...

From what I have read elsewhere I think I can hook the new pvc drain up to the existing steel pipe with a fernco coupling.
 
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Old 11-10-09, 02:06 PM
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Your revision is almost exactly what I just did (finished last week). The difference for me is that the shower was just a little further up that 3" branch. I believe it's to code (in any case it passed) to wet vent the toilet in this matter and then i have an air admittance valve (you have a real vent, though, so you're fine) for my vanity sink, which is venting everything, then the shower's p-trap has to be within I think 4' of where the vanity's vent attaches to the branch.

Unfortunately I did it like I did instead of like you did for the shower, the end result being the concrete was busted all to hell with the bad approach I used. I wish I had put my drain where yours is for the shower instead of where it ended up being

For the coupling you need two fernco (most popular in home depot and lowes) or american valve (both companies make them, if not more) couplings. Get ones specifically for metal to plastic as most of the shielded (i.e. stainless steel band around the entire coupling) ones are. The all-rubber without shielding ones are a touch cheaper and probably ok, including underground, but the shielded are a bit more heavy duty, so why not. On the coupling it will say on it something like "For CI to CI, Plastic, Copper). These are supposed to be tightened to 60 lbs/inch. I even spent $10 on the torque wrench specifically for them and that ended up stripping one of them. I would say just hand tighten "pretty tight" with a screwdriver or something, you really don't need to go crazy.

I'm not a plumber, I have about as much experience in this as probably you plus 10 days or so, but this is what I've learned.

Make sure you turn as gently as possible around bends, like for a 2" you can get long sweep 90 degree elbows. I didn't see those for the 3" but you could make one out of two 22 degree ones. When you hook the 3" into the main branch you can use a "combination tee" or a 3x3x3 wye like I have here with an additional 45 degree elbow into it, making a longer sweep; you won't be able to use a standard tee fitting with the short-sweeping 90' degree built in. Basically picture yourself as some water or an auger and if you need to clean them out how angles cannot be too harsh.

 
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Old 11-10-09, 02:49 PM
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Originally Posted by jasonk823 View Post
Well, I marked where my drains needed to be and I dug up my floor... only to find that the existing drain was positioned slightly different than I initially thought.

I made a revised layout of how I think my new drains should be. Any advice anyone can give will be appreciated!



FYI, this is a view looking down on the drains. I felt that was obvious by my wife is standing over my shoulder insisting that I clarify that point...

From what I have read elsewhere I think I can hook the new pvc drain up to the existing steel pipe with a fernco coupling.
1: You can use a Fernco coupling, but it should be a shielded type, that is one with a metal band covering the whole coupling, not one with two hose clamps on each end.

2: Your illustration shows a sanitary tee before the toilet, thats a no-no, you have to use a wye or a combine fitting in that location.

3: Where you are picking up your shower you have to delete the tee also, come off your 2in. line with long sweep ell or 45s to line up in the direction of the shower, then add a wye and 1/8 bend (or the fittings that will work), out of the branch of the wye you will run your vent, out of the front of the wye you will pick up your shower trap.

You should be getting closer to a final design, luck.
 
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Old 11-12-09, 07:18 PM
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shacko - thanks for all your advice! I do think I am getting closer. Here is what I have now - I think I integrated all the items you mentioned:



Hopefully I've got it right this time and I can put it all together soon.

Skoorb - thanks for posting the image. It is helpful to see a final design all laid out like that. You really cut up a lot of concrete. I ended up renting a jackhammer and, using a circular saw w/diamond blade, was able to just cut out the areas where my pipe is going. It was a LOT more work but I think I'll be thanking myself when it comes time to lay the new concrete!
 
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Old 11-12-09, 08:33 PM
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Originally Posted by jasonk823 View Post
shacko - thanks for all your advice! I do think I am getting closer. Here is what I have now - I think I integrated all the items you mentioned:



Hopefully I've got it right this time and I can put it all together soon.

Skoorb - thanks for posting the image. It is helpful to see a final design all laid out like that. You really cut up a lot of concrete. I ended up renting a jackhammer and, using a circular saw w/diamond blade, was able to just cut out the areas where my pipe is going. It was a LOT more work but I think I'll be thanking myself when it comes time to lay the new concrete!
Yeah, I frankly blame that on the stanley and black and deck books, both of which say it can be done with a masonry blade. this is simply terrible advice, it cannot be done; they are useless. Diamond blade plus sledge or better yet the approach you used, then I would have had only a few bags of concrete and framed on existing, older concrete instead of the ridiculous new patch I have.
 
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Old 11-13-09, 03:30 PM
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Skoorb,

Have you figured out how much concrete ur gonna need to fill in the space you removed? I know when I did mine I used a sledge also and had a ton of concrete to replace. If it's a lot (i think I used like 46 bags) I would recommend using a mixer. I bought one of the electric ones that you buy @ HD or Lowe's and it worked great. I could have probably rented one but I'm the type that buys everything and uses it later. I started by trying to mix it in a wheel barrel and dump it but man that was a TON of work. Letting the mixer do the work saved me hours and about 3 days worth of back pain.
 
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Old 11-14-09, 05:04 AM
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Originally Posted by shane21 View Post
Skoorb,

Have you figured out how much concrete ur gonna need to fill in the space you removed? I know when I did mine I used a sledge also and had a ton of concrete to replace. If it's a lot (i think I used like 46 bags) I would recommend using a mixer. I bought one of the electric ones that you buy @ HD or Lowe's and it worked great. I could have probably rented one but I'm the type that buys everything and uses it later. I started by trying to mix it in a wheel barrel and dump it but man that was a TON of work. Letting the mixer do the work saved me hours and about 3 days worth of back pain.
Wow, Shane, I feel better about my only 17 bags It was 80lb bags, I mixed it all with a friend using the plastic sheet method, which I think beats a wheelbarrow (although I've never tried any other method). If I was going to have done it myself I was going to rent a mixer. Home Depot had two sizes of them, the smaller for $45. I have read very positive reviews about the $150 mixer from harbor freight, too, actually. I poured it six days ago, it went well except I waited way too long for the final troweling finish so the surface is a bit of a mess, but that will be covered up.

Was your hole similar to mine in that the cracks just went haywire or did you have a very long trench to do?
 
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Old 11-14-09, 03:33 PM
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Originally Posted by jasonk823 View Post
shacko - thanks for all your advice! I do think I am getting closer. Here is what I have now - I think I integrated all the items you mentioned:



Hopefully I've got it right this time and I can put it all together soon.

Skoorb - thanks for posting the image. It is helpful to see a final design all laid out like that. You really cut up a lot of concrete. I ended up renting a jackhammer and, using a circular saw w/diamond blade, was able to just cut out the areas where my pipe is going. It was a LOT more work but I think I'll be thanking myself when it comes time to lay the new concrete!
You missed were I said to move the wye for the shower facing the shower and running your vent out of the branch, the idea is to have the shower wash the vent connection.
 
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Old 11-14-09, 10:11 PM
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I had my plan all laid out (thanks shacko) and was ready to start installing the drain. Just to make sure all my bases were covered I had a plumber come out for a quick consultation. He liked my plan but advised me to dig out a bit more of my existing drain to make the tie-in easier.

I went ahead and did that... and discovered that the underside of the drain was completely gone about a foot from where I was going to tie into it. So I kept digging up more and more of the drain, and it the underside kept being completly corroded away. Finally, after about 10 feet of no drain underside, the corrosion stopped.

Once I hade the entire 10 feet dug out I could clearly see that the drain was graded slightly in the wrong direction. My guess is that water and who knows what else was just sitting in that drain since for the last 60 years, slowly destroying it.

Now of course I am paranoid about the condition of the rest of the drains in the basement. I'm gonna have a guy come out with a drain camera and check them all out for me.

The only consoling thing in all of this is the fact that even if I had hired a pro to begin with the same problems would have occurred. It is nice to know that I am not the one that screwed it up!
 
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Old 11-15-09, 06:33 AM
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Originally Posted by jasonk823 View Post
I had my plan all laid out (thanks shacko) and was ready to start installing the drain. Just to make sure all my bases were covered I had a plumber come out for a quick consultation. He liked my plan but advised me to dig out a bit more of my existing drain to make the tie-in easier.

I went ahead and did that... and discovered that the underside of the drain was completely gone about a foot from where I was going to tie into it. So I kept digging up more and more of the drain, and it the underside kept being completly corroded away. Finally, after about 10 feet of no drain underside, the corrosion stopped.

Once I hade the entire 10 feet dug out I could clearly see that the drain was graded slightly in the wrong direction. My guess is that water and who knows what else was just sitting in that drain since for the last 60 years, slowly destroying it.

Now of course I am paranoid about the condition of the rest of the drains in the basement. I'm gonna have a guy come out with a drain camera and check them all out for me.

The only consoling thing in all of this is the fact that even if I had hired a pro to begin with the same problems would have occurred. It is nice to know that I am not the one that screwed it up!
Yikes, good call on having a guy come out.I would have thought it a waste of money but his idea alone has brought you to crucial knowledge about that drain. Once you replace it you'll have all new siny PVC and it should never corrode
 
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Old 11-15-09, 01:45 PM
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I hope you put a level on the part of the pipe that wasn't corroded to be sure that it has fall on it?
 
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Old 11-15-09, 11:40 PM
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Upon closer inspection the remaining existing pipe that is not corroded is clogged to all hell. i had a plumber take a look at it and he reccomends unearthing the rest of the pipe until I get to the junction with the rest of the plumbing system. all the other drains in the house appear to work fine; this drain i am currently working on was only ever used for a kitchen sink and kind of stands on it's own far away from the other stacks in the house.

the thinking is that since I've already got about 1/3 of it up I might as well pull it all up and replace it with pvc. one thing is for sure - i will be hiring some laborers for this!

i am leaving in a couple days for a nice long vacation. this whole mess will have to wait until i get back. good riddance to the stress, even if it is just temporary!
 
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Old 01-12-10, 02:55 PM
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We ended up unearthing ALL of the pipe under the slab - about 30 - 40 linear feet. It was almost all corroded out. Thankfully the pipe coming into the house was in fine condition. We had a pro come in and completely replace all of it. I sleep much better at night knowing that I should never had drainage issues!

On suprising thing we found is that our incoming sewer is at the rear of the house. We have a very large yard and behind us is another house with a large yard. I am still trying to find a sewer map but I am assuming there is an easement back there somehwere. I hope it is not underneath the new deck & patio we just built.

Thank you everyone for your advice. I wish the project had gone better so that I could have used it:-)
 
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