Tying Into A Waste Stack

[DIYDave]

I want to move my W/D to a different location in my basement. I want to move it about 4 feet to the right of a waste stack coming from a 1/2 bath above on the main floor. Its all newer plumbing done about 5 years ago (the upper 1/2 bath). I have seen several different ideas online but would like to know the best way to do it. Also during the 3-4 foot distance from the washer to the stack, can I angle the pvc pipe downward after the trap?

Thanks in Advance

Dave in Ohio

 

[Zanne]

I don't know about the tying in-- I think if you could supply pictures to show what the current setup is and maybe mark where you want to move stuff, it might help.

As for the downward slope after the trap-- are you talking about the pvc pipe for the washing machine?

Here is a diagram of a washing machine hookup:

From what I understand, the vent pipe must start at or before the drop/decline of the waste pipe. The slope has to allow gravity to pull the water down while allowing air to go up. So I think with a 2" diameter pipe you can have 5' to 6' of horizontal run before it needs to be vented with the pipe declining at 1/4" per foot.

If I'm wrong, someone please correct me.

 

[DIYDave]

I couldnt figure out how to get a picture in last night. Can I set it up just as the diagram above shows? DO I need a vent? I see some diagrams where they have tied into the stack at two different spots.

 

[DIYDave]

The downward slope I was referring t would be behind the trap leading towards the stack, this would be about 4 feet pvc pipe.

 

[Zanne]

What difficulty are you having with the picture you want to post? Maybe we can help you get it posted.

To answer one question: Yes. You DO need the vent. The reason for the vent is to allow the air pressure to remain balanced to prevent a vacuum from forming.

I believe you can set it up in a similar way as the diagram I posted. I just don't know what the stack you want to tie into looks like though. I'm not an expert so I'm hoping that one of the experts can weigh in.

As someone else described in another post, if you take a straw and put it in a glass of water water, then hold on to the top of the straw (creating a seal) you can lift it up and the water will stay inside the straw. This is what happens when you don't have a vent. When you take your finger off of the top of the straw, the water drops out because it now has air to allow it to flow. The pipes work in a similar manner.

I believe that after the trap, you need to have a downward slope of 1/4" per foot toward the stack. Less slope than that would make it harder for the water to travel and more than that would make it so the water level would be too high in the pipe and would create a seal that prevents air from coming up. Basically the slope cannot exceed the diameter of the pipe before the vent.

Please ignore that the person who labeled the first image put waist instead of waste. LOL.