Trap hight vs. hight of connection to vent / drain??? (was sweating a 2" brass...)

[Steve]

I'm replacing kitchen cabinets. The old drain ran horizontaly about 2' through the back of some of the cabinets and T's into a vent going up and drain down. The new Cabs have slide out accesories that wont allow me to cut into the cabinets. I plan on dropping the new drain straight down (after a trap of course) through the base of the sink cabinet and the floor. A couple of turns and I'll tie into the same vent / drain as before but now it will be in the basement.

The drain will still be vented but the tie in will be 2 -3 feet below where it was.

MY QUESTION >>>>>

I may be missinterpreting the 1st sentence in the following response to an earlier post???

You cannot run a drain line down straight to the basement floor without a > vent running up through the roof. Most codes allow about 5 feet of > horizontal run from the sink trap before it has to split into the drain > going down and the vent going up. Which is why you have the current > arrangement. You would be better served by trying to work with the line > that you want to abandon as it probably has a vent running vertically > within the wall. > > If you don't want it to run through the cabinets, possibly you could drill > through the studs and fit the pipe in there.

The only problem I can see with what I want to do is that the connection to the vent / drain will be 2 - 3 feet lower than the hight of the trap under the sink..

So the drain line will be vented but does the tie in to the drain / vent line have to be at the same hight as the trap??? If so, could I just move the trap down to the basement and but it at the same level as the T into the drain / vent ???

Hope this make sense??

Thanks for any help.

Steve

Yes, where the horizontal line from the trap connects to the T in the wall, the vent goes up the wall and the water goes down. Is the relationship between the hight of the trap and the hight of the horizontal connection to the vent / drain line important? what I'm doing will drop the drain line down through the floor and connect to that same vented pipe. This will put the connection to the same vent / drain but will now be in the basement about 2 - 3 feet BELOW the trap thats under the sink..... Originally I was going to run horizontal through the wall and come out into the sink cabinet, but the stud I would have to cut through is doubled up

2x4's on the side of the kitchen window I'm also replacing. The original pipe T hugs these studs now. and the stud is already notched a bit to allow the current T to angle towards the old sink. I wasnt shure if I should cut out these 2x4's as nothing would be supporting the side of the window ????

Again, I guess it all comes down to: Is the relationship between the hight of the trap and the hight of the horizontal connection to the vent / drain line important?

What problems would it cause??

There is nothing else connected to the vent pipe above this connection, It goes straight to the roof.

Also, is the suggestion to use Mapp torch because of the brass or because of the 2" pipe? I am using propane now...

I got brass because thats all they had! HDepot = no 2" connectors Local hardware = no 2" anything closest plumbing supply only had a brass T / Y ?????

I redid the hot and cold lines last night and I'm going to tackle the drain as soon as I figure out which way to go Thanks for any help

Steve

[Wayne Whitney]

Consider modifying the affected slide out accessories to be less deep so that you can use the same piping layout as originally.

This won't work, the trap arm (pipe between the trap and the drain line) needs to be horizontal until it ties into a drain/vent with a sanitary tee.

You've spoken about the need to notch/drill wall studs, consider using these: . Also, if you do have to notch/drill wall studs, then it is better to do so for 1 1/2" pipe instead of 2" pipe. The drain has to be 2", but the trap arm and vent can be 1 1/2".

So one option is to run the trap arm straight into the wall, hitting a vertical drain/vent segment with a sanitary tee. The vent side goes up until it is forced to jog horizontally by your kitchen window; after jogging, you can tie into the existing vent. [Note: you are required to be at least 6" above the kitchen sink flood rim before the vent can turn horizontal.] The drain side can go down into the basement before jogging to tie into the existing drain. This way you only have to drill/notch studs for 1 1/2" pipe.

Cheers, Wayne

[Don Young]

At least some plumbing codes strictly forbid the use of "S" traps and drains thru the floor because of the high risk of siphoning the trap dry. Code compliance is for safety and satisfactory performance. It is even more important for non-professionals who may not recognize possible hazards.

Don Young