[jtb587]

I am planning to install a washing machine in my basement. The only catch is that the basement is below my sewer line. I have 1950's era cast iron drain pipes.

I want to use a grey water pump to pump up into the sewer line. I plan to run PVC from the pump discharge to the cast iron. What is the best way to tie these two pipes together?

 

[carpdad]

The washing machine is a pump so that you may not need another pump. Also, don't know if this is legal now, but I've seen (NJ) old setups where there was no trap but a one way valve at slight angle so that the gate closes when not used.
Otherwise, support the cast iron pipe. Use cast iron pipe chain cutter, then slip in 4x4x2 wye and join with nohub coupler. This is if pipe youre cutting is horizontal. Vertical pipe, use sanitary tee. You may need vent on the pump housing.

 

[rjniles]

How far above the floor is the drain line to sewer or septic? Show us a picture.

 

[jtb587]

Sorry for the delay in response.

The drain line is about 6 feet off of the basement floor. I know some washing machines will pump this high but as far as I know (correct me if I am wrong) against code.

I have been looking at pumps that could do it and I think that is the route to take. I am still researching plumbing code to make sure I make the tie in correctly. My plan currently is to take a PVC Tee and use no hub clamps to attach it into the system. As far as P-traps, check valves, and vents what is required to make this work?

 

[TheEplumber]

What I do in my area is to use a laundry sink plumbed to a small pump basin. The washer discharges to the sink. Then the pump lifts it to the 3" or 4" building drain.

Use a wye- not a tee- to tie the pump line in. The wye should be on it's back so the pressure line inters the top of the gravity line.

Your pump needs a check valve and a full port gate/ball valve as close as possible to it
https://www.libertypumps.com/Products/Category/SubCategory/Product/?p=19&s=8&c=15

 

[rjniles]

You really need to show a picture of the existing drain layout. You best bet mat to install a laundry sink next to the washer and drain into that. Then us a pump to drain the sink. You will need a trap and the drain must be vented.

 

[jtb587]

Here are pictures of my current drain line.

Rjniles - What would be the advantage of installing a laundry sink to take the water from the washing machine? The only thing I can think of is that I would eliminate the risk of the washing machine filling the basin faster than the pump can empty it.

Also, what is the best way to vent the pump discharge? I don't think running a vent stack up through the roof is possible without tearing a lot of wall and floor apart.

 

[rjniles]

The wash machine will pump the water faster than the pump can handle. You can use an AAV (air admittance valve) if your area allows it. Call your building official.

 

[Ghostmaker]

Eplumber is correct have a great day.

 

[jtb587]

The third picture shows the horizontal run I would tie into. Although why would I need a wye and not a tee? If the tee makes the piping geometry easier what is gained by using a wye?

Also, if I put the check valve close to the pump wouldn't that make it so my pipe was always full of water? And would I need a p-trap for this? I would assume I'd put the p trap in the joists just above where I would come down into the main pipe.

 

[TheEplumber]

You need a wye because code dictates it in this application.
Tees are not allowed in horizontal drainage application.

In your case a trap is not needed. The sink will be directly connected to the dump basin. It will then pump through a check valve to the bldg. drain.
The check valve needs to be near the tank. If not, your pump could short cycle as the vertical water head drains back to the pump.
An AAV is one way valve so it won't work properly on a pump. Simply run the pump vent up to joist height then turn it down with a couple 90's.

 

[Tom738]

Disclaimer: I am not a plumber and have not checked code.

However, just to throw a possible option out there depending on what you want, basement layout, heights, etc...

Some places put laundry machines on a slightly raised section of floor within the basement. I have no idea if it's a common practice, but I've certainly seen it.

(In that case, there was room for a washer, a dryer, a laundry sink, and the person operating them on a floor 7-9 inches up from the main floor, with a bit of room to spare.)