Adding a utility sink to a basement washing machine room

[joeg13]

I want to add a utility sink to my basement washing machine room. Currently, the washing machine drains into a drainpipe that comes out of the foundation about 4 feet above the floor. I would like to add the sink next to the washer. I think I need a sump pump since the sink will sit lower than the drain pipe. I'm not sure how to have both the washing machine and sink empty into the same drain pipe without one backing up into the other. I'd like to set it up similar to the diagram, but I'm confused about the joint that I circled in red. Do I use a T joint of some kind? Do I need to attach the washer at a higher level than the sink? Is it possible to do what I want? Please help. Thanks in advance.

[LazyPup]

Technically speaking sump pumps may only be used to discharge storm drainage and may not be connected to the DWV (Drain, Waste & Vent) system.

The discharge from a laundry sink is tecnically defined as sanitary waste and requires an approved Sewage Ejector Pump. Sanitary sewage may not be discharged through a sump pump.

After discussing this idea with a couple colleage's who are Plumbing inspectors we are all of the concensus opinion that you could take advantage of a rather gray area of the code providing it is not rejected by your local inspector.

If you were to cut a hole in the concrete and install a permanent sump or catch basin that would be considered a permanent fixture and as such you would be required to install an approved sewage ejector complete with a water tight lid and a vent through the roof, howver, if you use a crock or vessel sitting on the floor and fitted with a utility pump you could then make the argument that it is not a plumbing fixture but rather it is an appliance in the same manner as the washing machine or a condensate lift pump on an HVAC system (providing you do not connect a watercloset to the crock.)

As an appliance the discharge must then be connected to the house DWV system by means of an indirect waste receptor which in this case would be the washing machine standpipe.

To make an approved standpipe you would first come off the existing drain line with a 2" P-trap, then install an 18" PVC riser on the input of the P-trap. (The code minimum for a washer standpipe is 18" vertical above the trap.)

There are a number of small submersible utility pumps such as those made by "Little Giant or Wayne Pumps" that have a 3/4" garden hose connection on the output that would suffice for your needs. You could then attach an appropriate length of 3/4" garden hose and on the output end make a U shaped section of copper or aluminum tubing which could be inserted into the garden hose and connected with a radiator clamp. The Inverted U shape would then hang on the top of the standpipe to make the final connection. (The pumps are typically about $75)

For a control system you can get a submersible float switch that is made for sump pumps that has a long cord attached. The switch assembly is secured to the pump by means of a large radiator clamp and the cord goes up to your outlet. The switch cord is plugged into the outlet and the pump is then plugged into an outlet on the switch cord. Once this is set up as the water rises in the holding vessel the switch floats upward and turns the pump on. As the water level drops the switch then floats down to the horizontal position and turns the pump off. (Accessory float switches are typically about $20).

Both the washing machine and the pump can share a common standpipe.

[joeg13]

pump

This is the pump I was considering buying. Would this do the job?

http://www.flotecpump.com/asp/Product.asp?PId=305

[LazyPup]

The pump in your link is a self contained sewage ejector pump, which definitely would serve the purpose however it presents a number of technical problems.

First of all, if you examine the top of the enclosure you will see two pipes coming off the top. One is the discharge pipe and the second one is a vent line which must be connected to a vent to the roof.

The discharge line must then run vertical to a point above the gravity flow drain line to which you will connect it. The discharge line must then be connected to the gravity flow line by means of a Wye connection with the side opening on the top of the pipe.

There must be a "Backflow preventer" installed on the vertical riser from the pump and it must also have a manual DWV rated gate valve above the backflow preventer.

The real problem is the output rate of the pump. That pump is rated at 2880gal/hr.

2880 / 60 = 48gal/minute. (Under the International Residential Code the Code minimum for a sewage ejector pump is 14.2gal/min while the Uniform Plumbing Code minimum is 20gal/min.)

Before connecting the pump to the house drain system under the International Residential Code we must compute the load at 1.5DFU'd (Drainage fixture units) for each GPM from the pump. (Uniform Plumbing Code demands 2DFU for each GPM).

The pump discharges 48GPM so the output load is now:

International Residential code= 48gpm x 1.5 DFU = 72DFU
Uniform Plumbing Code = 48gpm x 2 + 96DFU.

This DFU load must then be added to the existing DFU load on the drain line.

Under the International Residential Code the maximum permitted DFU load on a 3" branch line is 20DFU and the maximum permitted load on a 3" house main drain or house sewer with a 1/8" per foot pitch is 36DFU and with a 1/4" per foot pitch it is 42DFU.

Under the Uniform Plumbing Code the maximum permitted DFU load for a 3" horizontal branch line is 35DFU and for a 3" house main drain or house sewer the maximum permitted load is 35DFU.

This means that if you use the pump in your link it must be connected to a 4" drain line. Many homes only have a 3" line, therefore in order to install that pump you would need to change the entire main drain and house sewer line to the municipal sewer connection.

[joeg13]

Another pump

Is this pump more appritate? It doesn't seem to need to be attached to a vent pipe.

http://www.lowes.com/lowes/lkn?actio...esc&lpage=none

http://www.waterace.com/pdf/R3S%20R3...s%20Manual.pdf

[joeg13]

Current setup

Here's a picture of my current setup. Thanks again for the advice.

[LazyPup]

All the pumps shown in that link are sump pumps and would be much too big for this application.

In order to use a pump that is directly coupled to a drain line to lift waste the pump would be required to be ASTM listed as a "Sewage Ejector Pump"

A Sewage ejector pump is required to be sealed inside a water tight enclosure with a removable service access cover and a separate vent through the roof of the structure.

The output of the pump is required to be rated at 1.5DFU's for each GPM from the pump, which means the pumps illustrated would be 1.5DFU x 30gpm = 45DFU of load on the line it discharges into. That means it would be required to discharge into a 4" or greater line.

The present washing machine connection illustrated in your photo is also a violation of code because it is directly coupled to the drain line. Washing machines are required to discharge into an "indirect waste receptor".

You could create an indirect waste receptor by disconnecting the present hookup, then extending the copper input pipe on the P-trap a minimum of 18" vertically providing that is a 2" diameter line and connecting the washing machine drain line in the conventional manner.

Below I have illustrated a method whereby you can use a small utility pump in a catch vessel under your sink to pump the water up to the washer standpipe. Since the pump is portable and the discharge is connected to the input side of the P-trap it would be classified as an appliance instead of a sewage pump therefore it would be acceptable.

[joeg13]

The full picture

I think I understand all of the instructions you've given me. I'll shop for a much smaller pump that pumps at the rate you've suggested. I updated your picture to show my understanding of the complete hookup. The main thing I added which I'm not sure if it's correct is the double sanitary tee with the backflow preventer. Did I get that right? Please let me know how I did. Thanks again.

[kactuskid]

What would be prohibitive about installing a sealed box such as is on the link below that contains a pump in it. Then instead of tying into the main stack to vent, an air admittance valve could be used instead. Home Depot sells small contained units such as this, couse the link also provides the name of a supplier.

http://www.popularmechanics.com/home...t/1275616.html

Just curious?? Thanks

[joeg13]

kactuskid

The sealed box is a great idea. The Flotec pump that I provided a link to in my second post is a sealed box that contains a pump like you're descibing and shown in the Popular Mechanics article. It's sold in Home Deopt. I just need to find one that is less powerful since LazyPup said the Flotech one pumps too many gallons per min. I agree with you and was hoping to find something like this.

Your suggestion of an air admittance valve, solves the problem of not wanting to tie into the existing vent pipe.

I think my last problem is how to attach both the waste pipe/hose from the sink pump and the waste hose from the washing machine to the same 18" stand pipe. Would I use a double sanitary tee with backflow preventers as I added to LazyPup's diagram? Or is there a better way?

[LazyPup]

Kactuskid,,

Providing the waste is strictly "Greywater" the receiver and utility pump configured as I illustrated would be acceptable because it is a non-permanent mount, connected by a plug into a convenience outlet and attached to the DWV system by means of an indirect waste, therefore it may be classified as an appliance. If any of these conditions were changed, I.E. discharging a water closet into the receiver, creating a permanent sump pit, hard wiring the pump motor of directly attaching the pump discharge directly into the DWV system would then classify it as a permanent installation, and would then be required to meet ALL OF THE STANDARDS of an approved "Sewage Ejector Pump system"

The standards for a Sewage Ejector System are very strict:

(Note -IRC= International Residential Code & UPC= Uniform Plumbing code)

1. The sump discharge must be lifted above the gravity flow drain (IRC3007.2 & UPC 708.0)

2. The discharge must be connected to the gravity flow drain by means of a Wye fitting with the side opening on the top of the gravity drain. (UPC 710.4)

3. The sump must have a vent through the roof. (IRC T3113.4.1 & must be a min. of 1-1/4"through the roof.) (UPC-710.10 must be a min. of 1-1/2" and must run through the roof.) (Air Admittance Valves are not permitted here)

4.Sump must be fitted with a removable water tight cover (IRC3007.2) (UPC710.10)

5. The lowest inlet to the sump must be a minimum of 2" above the highest start level of the pump. (UPC 710.9)

6. The minimum capacity of the pump must be- (IRC 3007.1 = 14.2gpm) (UPC 710.3.1=20gpm)

7. Backwater valve required on the pump discharge pipe (IRC 3007.1 (UPC 710.4)

8. An approved DWV grade gate valve is required on the discharge side of the backwater valve (IRC3007.1) (UPC 710.4)

9. A minimum 2" diameter discharge line from the pump (IRC3007.1 -Exception- if the pump is equiped with a macerator grinder the discharge line may be 1-1/4") (UPC minimum 2" -No exception- UPC 710.3.2)

10.The gravity drain receiving the discharge must be sized at: (IRC= 1.5DFU for each GPM from the pump- IRC-T3007.1) (UPC = 2DFU for each GPM from the pump-UPC 710.5) Note, this DFU value is in addition to the present load on the pipe.

Now here is the catch that will cause most ppl problems when attempting to install sewage ejector pumps:

Per the IRC the pump min. is 14.2gpm and the load is 1.5DFU/GPM.
14.2 x 1.5 = 21.3DFU which must be added to the DFU load that already exists on the pipe.
Per the UPC it's 20GPM x 2DFU= 40DFU, here again, in addition to the load already existing on the pipe.

Per the IRC a 3" horizontal branch drain line may not exceed 20DFU & a 3" horizontal Main Drain may not exceed 36DFU. In most instances once you compute the existing load a 3" line simply does not have the capacity to take on an additional 21.3 DFU load which means the sewage ejector would need to be connected to a 4" gravity flow line, and many homes only have a 3" main drain & sewer so in order to install a sewage ejector they would need to change the house main drain & house sewer line all the way to the municipal sewer tap or the septic tank.

The UPC will allow 35DFU on a 3" horizontal branch but the sewage ejector is rated at 40DFU by itself, therefore, here again you would need a 4" house main and sewer.

Obviously spending $1000 on a sewage ejector pump assembly plus installation cost of changing the entire sewer run would make this project cost prohibitive, which is why I suggested the utility pump as an alternative.

[kactuskid]

Ok, I understand what you're saying now. So, Joe could hang the washers drain line into the laudry tub secured with a clamp, the discharge of water into the laundry tub would be pumped out of the tub via the appliance pump underneath and into the top of the standpipe. This being an indirect connection would be within code. This would also allow a big catch basin for the laundry discharge and abliity to catch all the lint by installing a nylon stocking around the end of the washer discharge hose.

[joeg13]

I've seen that setup suggested elsewhere, but then the pump will get used each time the washing machine cycle drains. Won't that overwork the pump? I was hoping to have them empty separately into the drain pipe.

[kactuskid]

The pump should handle it fine. A ton of people have problems using standpipes. A couple main reasons I always hear complaints about are how the drain piping gets clogged up. This is due to not being able to prevent all the lint from going into the drain. You won't beleive how much lint is discharged from a load of laundry. Once you have a nylon stocking wrapped around the discharge pipe you'll see how often you need to swap it out.

Another problem with the standpipes is that the volume of water is so great from the washer that the standpipe gets overflowed very easily. By using the tub, the volume of water is absorbed and not an issue then. Course LazyPup may have a better alternative for you that would prevent the above. I'm always interested in learning a new way.

[joeg13]

I've been in my house for a year and a half and never had a problem with my current setup (see picture) getting clogged. I suppose it could always happen. I am hesitant to add an additional point of failure (the sink pump) to the laundry setup when all I wanted to do was add a sink that will get minimal use.