I've been working on the layout for a bathroom in my basement and I'm trying to figure out how to connect a new drain and vent for a tub/shower. Hoping someone can help...

Rough-ins for the sink, vent, and toilet already exist but it looks like the builder did not leave a rough in for the tub/shower. I did some pounding on the slab to be sure but could not find any hollow spots or a skimmed over trap.

Here are some pictures of what exists and what I hope the layout to be.

<table style="width:auto;"><tr><td><a href="http://picasaweb.google.com/lh/photo/0Are3stqg8giCM9MDjM3uA?feat=embedwebsite"><img src="http://lh5.ggpht.com/_lb5T2vSlNM4/TNHGo1H05QI/AAAAAAAABNc/nW-XICiGIHk/s400/bathroom.jpg" height="366" width="400" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/maxfletcher/PlumbingPics?feat=embedwebsite">plumbing pics</a></td></tr></table>

Here is a picture of what currently exists and some help from massplumber2008 on how to hook up the sink...

<table style="width:auto;"><tr><td><a href="http://picasaweb.google.com/lh/photo/zFAg653pSkZuKj8UVcnBEQ?feat=embedwebsite"><img src="http://lh3.ggpht.com/_lb5T2vSlNM4/TMhFPH5iXhI/AAAAAAAABNA/4pibwrYrZIQ/s400/attachment.jpg" height="294" width="400" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/maxfletcher/PlumbingPics?feat=embedwebsite">plumbing pics</a></td></tr></table>

Hi again...

Your pics. Didn't post. Please repost and I'll see if I can draw something up for you.

Mark

Here is a link to the pics:

http://picasaweb.google.com/maxfletcher/PlumbingPics?feat=directlink

Thanks,
Max

Hi Max...

Sorry, lost you in the shuffle!

If I remember correctly wet venting is allowed in your area. Here, you should just need to cut into the lavatory (sink) drain and run a pipe over to the tub. You'll use the 2" lavatory drain/vent to wet vent the tub...

In my picture below I drew up what I think might be underground in GREEN. I drew up what I think you need to do in YELLOW.

I'd break out the concrete by what I'm calling the sink drain and connect into that drain with a wye fitting... run to a PTRAP directly under the tub waste assembly.

Back to you, now...

Mark

Mark, thanks so much, this is really helpful. You are exactly right with the location of the existing pipes. I just need to make one small change to fit a door in the bathroom and that is to move the tub/shower to the other side of the cleanout. With the tub/shower on the other side of the main line would I still tie into the sink drain/vent as wet vent? Or should I tie into the main line and use a horizontal branch arm vent to tie into the vertical vent?

Here is an overhead drawing of my proposed layout:

<table style="width:auto;"><tr><td><a href="http://picasaweb.google.com/lh/photo/0Are3stqg8giCM9MDjM3uA?feat=embedwebsite"><img src="http://lh5.ggpht.com/_lb5T2vSlNM4/TNHGo1H05QI/AAAAAAAABNc/nW-XICiGIHk/s288/bathroom.jpg" height="263" width="288" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/maxfletcher/PlumbingPics?feat=embedwebsite">plumbing pics</a></td></tr></table>

Hey Max...


You asked, "With the tub/shower on the other side of the main line would I still tie into the sink drain/vent as wet vent? Or should I tie into the main line and use a horizontal branch arm vent to tie into the vertical vent?"...

Great question... ;)

In this case your drain line (from sink drain/vent) would probably run into the main drain and you are also probably too far for a wet vent anyway at that point so you will probably be better off connecting into the main drain with a wye fitting and piping this up as drawn below.

I'd pipe it all up 2" underground. I'd install 2" test tees (cleanouts) right out of the ground on all pipes coming out of the ground (can make accessible through access panels to adhere strictly to code). I'd use a 2" long sweep elbow out of the ground at the tub vent, install the test tee and then reduce to 1.5" pipe to the other vents.

The vent wye fitting needs to roll above the center line of the 2" drain pipe going to the tub waste....can be just above or rotated straight over the top of the drain...depends on depth of pipes...don't want the vent pipe up in the concrete floor, right?

Pipe a 2" long sweep elbow for the tub drain and install a 2" PTRAP and reduce to 1.5" to pick up the tub waste and overflow assembly.

Pitch the vent pipe 1/8" t0 1/4" from the vent stack back toward the drain.

Hang the pipe every 3-4 feet.

Be sure to pay attention to orientation of the vent fittings... rain water from the roof must FLOW with the fittings to the drain.

Check the drawing below. Let me know what questions you have...

Mark

PS: By the way, you'll want to flip the tub (and therefore the plumbing below) so you can have access to the drain pipes from the hall (?) now and in the future. Leave a 12" square box out in the floor so you can connect the trap and the tub waste.