Plumbing Question With pic

Willc

Well-Known Member
Joined
Mar 31, 2005
Location
Shelby
I am relocating the door in the laundry room and
InkedIMG_20170701_135129_LI.jpg
raising the floor.I need to move the drain . To get proper pipe fall I want to locate the p trap six'ish feet from device with proper pitch running to the trap.
Will it work still? Code be damned before I jack hammer up slab.
 
why not just put the trap behind the wall like it is originally. then run your pipe directly into drain with proper fall


in theory it would work as long as your trap and pitch are right
 
because where I can run the 90 above the 45 coming out of the floor will put me at the height of sub floor.If I long sweep 90 to the P trap that should place the bottom of p trap on the slab giving me about 3 inches to get pitch between new drain box before it hits p trap.
I
 
The laundry box on the right is how it's supposed to be plumbed. Your blue line is not.
 
I'm no plumber but my understanding of physics and water flow is that a p trap only works effectively at the bottom of a (semi) direct vertical flow.
 
^^^ this, unless you get (make) a very deep p-trap, it will not be effective.
 
Ron said:
I'm no plumber but my understanding of physics and water flow is that a p trap only works effectively at the bottom of a (semi) direct vertical flow.
Click to expand...

This is a p trap, not a commode. P trap is just to prevent sewer gasses from coming back thru the piping.

If there's enough fall it should work. It won't be pretty or right but it would work.
 
awheelterd said:
This is a p trap, not a commode. P trap is just to prevent sewer gasses from coming back thru the piping.

If there's enough fall it should work. It won't be pretty or right but it would work.
Click to expand...

You still have to have enough downward force to overcome the gravitational rise. If you stretch the fall over the run you lose velocity to surface friction.
 
Washing machines drop a shitload of water all at once. That's why the code says there has to be an eighteen to forty-eight inch standpipe above the trap. It's so there's enough vertical column to clear the trap without having water standing in the pipe. Have the trap in the wall like it's supposed to be, then tie into the 3" line below the floor.

It's also going to need a vent to keep from sucking the trap dry.
 
The drawing shows the trap below the floor, and tying into the stack above the floor. Both of those are verboten. If the trap discharge is higher than the inlet, the entire lateral will stay full of water. The first time the machine cycles, it will fill the lateral pipe. When it gets to the rinse cycle, water won't flow down the pipe and it'll flood the room.
 
So if the laundry box is the higher end of the lateral pipe, and if you still need to find vertical room for the bend in the P trap, clearly it would be better to have the P trap at the laundry box end. That's obviously where it wants to be for proper function already.
No matter what, you're going to have to cut up that drain connection where it enters the slab, and it would be much better to make that a simple connection rather than having to package a P trap in that area. That's separate from the obvious functional problems of having the P trap in the wrong location.

That's my non-plumber point of view.
 
So this is just for laundry exhaust?
What is the pump rating on the washer? If it's not enough, get a secondary pump... and run it up and over through the ceiling over to the existing line.
People do this in basements all the time.
 
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