DWV Layout - Please Review

**sjsmithjr** · 12-12-2005, 02:13 PM

Budget overuns on a house my wife and I are renovating are making it neccesary for me to do something I haven't done in a looong time - install a dwv system. Heck, even when I was doing it it was under the watchfull eye of a master!

The major code where I'm at is the Southern Building Code. Hopefully the attached image of my poorly drawn isometric drawing is understandable. The drawing can also be viewed by following this link DWV Layout

Although you can't tell it from the isometric, the wyes on the horizontal are on their side.

Thanks in advance.

-Sam

**Terry** · 12-12-2005, 02:44 PM

That would work with the UPC code.

**dubldare** · 12-12-2005, 04:52 PM

Before I could fully comprehend it, a wise plumber told me... "Go to your vent first."

Piping in this way will eliminate the unwashed, flat water closet vent.

**FloridaOrange** · 12-13-2005, 02:55 AM

I was taught that if you can, head for the water closet first. Doing it that way usually a bathroom can be plumbed and vented off of the lavatory only (as long as the wc isn't flushing past the shower of course).

**Cass** · 12-13-2005, 04:16 AM

No message

hj · 12-13-2005, 05:07 AM

All the previous comments are correct. My only addition is that what you call a "Y" is probably a combination Y-1/8 bend from the way they are drawn.

**sjsmithjr** · 12-13-2005, 11:32 AM

Thanks to everyone for their comments and suggestions. Of course, I liked Terry's "that would work" best!

What dubldare is suggesting makes sense, and I'll change the way I plumb the drain at the water closet.

I've run drains the way FloridaOrange suggests; somewhere along the way I picked up the idea that individual drain runs to the horizontal work better in the long run. Follow up comments on the merits of either approach would be appreciated.

Finally, my drawing must be as bad as I thought. I wasn't planning on using combo wyes on the horizontal. Instead, I was going to rotate the long sweep 90s 45 degrees.

Again, thanks to everyone.

-Sam

**FloridaOrange** · 12-13-2005, 11:47 AM

Wish you well on your project. I'm in S.Florida, everything is run as shallow as we can, most times backventing wc's (or showers) isn't real practical. I was just indicating the way I would have approached it but anyway that keeps your fixtures vented will work.

**sjsmithjr** · 12-14-2005, 09:40 AM

You're absolutely correct, FloridaOrange. If I had limited altitude or were building slab on grade I'd definately take your approach. Guess I'll head over to the house now to see what cost overuns, I mean problems, the carpenters have found today.

Thanks again to everyone.

-Sam

hj · 12-15-2005, 05:32 AM

Finally, my drawing must be as bad as I thought. I wasn't planning on using combo wyes on the horizontal. Instead, I was going to rotate the long sweep 90s 45 degrees.

In that case the lines to the long sweeps should have been horizontal rather than on a slope. In any case, I will try to arrange my systems so as much as possible connects to a single point. Which in your case would mean the toilet would go into a sanitary tee with a left hand inlet. The shower would go into that, which means it would not need its own vent, and the lavatory would arm over to the toilet's vent, so it would not need a vent either.

**sjsmithjr** · 12-15-2005, 06:42 AM

Thanks guys. I believe the consensus is that my bathroom dwv layout should look more like the attached drawing. Much simplier and easier to install!

-Sam

**dubldare** · 12-15-2005, 07:58 PM

As long as no offsetting of trap arms beyond the 90 degrees shown, and maintaining adequate trap arm distances, you'll be fine in the situation shown.