A plumbing question

[JollyRoger]

I had to open up a wall to do some electrical work downstairs in my workshop, and had one of those "a ha!" moments as I discovered that the sewer line for the upstairs bathroom passed right through it, and there was a cold water line there as well, so I said to myself, gee, I could add a toilet right here without going to a lot of expense, and since it is the old workshop, I could use that old toilet I have out in the shed and all. I could build a little plywood box, install the commode on top of it, and have just enough room without having to cut a hole in the slab,and then run the vent up the outside wall to the roof. So my first question is, do I need to install a P-trap in the sewer line or does the internal plumbing in the commode handle all that? If I can just use a Y pipe from the commode to the sewer line, everything will fit into my little white trash plumbing box I want to sit the commode on.

[jplinville]

The commode has an internal P-trap, so another wouldn't be needed.

Two things I've learned from household plumbing...crap won't run uphill, and don't chew your fingernails.

[jplinville]

Also...make sure you have the line vented within 3 foot up line, or you will have issues with it clearing the drain line.

[JollyRoger]

Yes, I learned the three rules of plumbing at one time, the other one is "pay day is Friday" IIRC. Thanks for the info!

The pipe I am tapping into is coming down from the second floor, I'm assuming I can just tee into the line above the Y connection for the commode, install an elbow and run the vent pipe up the outside wall to the roofline .

[lutzTD]

first let me say Im not a plumber. If you cut into the line in the basement, what happens if the sewer line gets stopped? will a flush from above come gushing out the lower commode? Should there be some sort of backflow preventer?

[JollyRoger]

Originally Posted by lutzTD

first let me say Im not a plumber. If you cut into the line in the basement, what happens if the sewer line gets stopped? will a flush from above come gushing out the lower commode? Should there be some sort of backflow preventer?

Well, if it did it would be unpleasant, but this is going into my shop, so it would not be the total disaster that subjecting the Mrs to something like that would be. It's not going into a basement, here on the Gulf Coast, our houses are up on stilts because of the hurricanes, so living quarters are on the second floor, and anything you build or enclose on the first floor is done with the expectation that it could, or more likely will, all end up under six feet of water some day, so there is not much in the way of flooring or anything special that would get damaged since it is all designed to go under sea water for a week or so if need be, and the walls are designed (using washable wallboard as cover over styro sheeting insulation) so you can just remove them easily and then hose the place out when you need to get rid of the dead fish and alligator poop after the next 'cane comes around. Adding this is really just a convenience so I don't have to go running up a flight of stairs every time duty calls while I am puttering in the shop with the old 280E.

[lutzTD]

Originally Posted by JollyRoger

Well, if it did it would be unpleasant, but this is going into my shop, so it would not be the total disaster that subjecting the Mrs to something like that would be. It's not going into a basement, here on the Gulf Coast, our houses are up on stilts because of the hurricanes, so living quarters are on the second floor, and anything you build or enclose on the first floor is done with the expectation that it could, or more likely will, all end up under six feet of water some day, so there is not much in the way of flooring or anything special that would get damaged since it is all designed to go under sea water for a week or so if need be, and the walls are designed (using washable wallboard as cover over styro sheeting insulation) so you can just remove them easily and then hose the place out when you need to get rid of the dead fish and alligator poop after the next 'cane comes around. Adding this is really just a convenience so I don't have to go running up a flight of stairs every time duty calls while I am puttering in the shop with the old 280E.

cool, I had thought of buying a stilt house here in Tampa so I could get the free shop underneath. In the end I bought a slab house at higher elevation and Im building a detached garage.

[jplinville]

Originally Posted by JollyRoger

Yes, I learned the three rules of plumbing at one time, the other one is "pay day is Friday" IIRC. Thanks for the info!

The pipe I am tapping into is coming down from the second floor, I'm assuming I can just tee into the line above the Y connection for the commode, install an elbow and run the vent pipe up the outside wall to the roofline .

Or, if your basement is only partially underground, you can cut a hole in the side wall leading outside and vent it there...I just had my all of my sewage lines replaced a few months ago, and that's how we ended up venting.

[JollyRoger]

Originally Posted by jplinville

Or, if your basement is only partially underground, you can cut a hole in the side wall leading outside and vent it there...I just had my all of my sewage lines replaced a few months ago, and that's how we ended up venting.

That's the plan!

[kerry]

Yes, you can do that.

[Honus]

Consider getting a wall-mounted commode. Adds more money to your project, but might be a nice installation without the need for cutting into the floor.

[JollyRoger]

Never thought of that, thanks!