Sewage info to move washer from kitchen to garage

Long story: The first owner of our 1958 Sunnyvale courtyard model Eichler moved the washer and dryer to the garage. And they did it very poorly: They popped a hole in the wall and ran a hose out to a barrel. A sump pump in the barrel was used to feed a hose that dumped the wash water into a planting bed. And they used an existing 15 amp electrical outlet for the washer, dryer and sump pump. All the other owners in the intervening 40 years put up with the sanitary and maintenance issues of this illegal greywater system. (My pet peeve was cleaning the lint and dog hair out of the sump pump's intake every couple of weeks.) The only bright spot was that they did a decent job on putting in a gas outlet for the dryer.

When we moved in we had some electrical upgrades done and at that time had the electrician put in code compliant outlets for the washer and dryer. Just recently we had a plumber install a drain and we had the whole setup brought up to code, permitted and inspected.

With that in mind, here are some thoughts on the topic.

First, locate the sewer. In our Sunnyvale neighborhood there are "S" and "W" letters embossed in the concrete curbs in front of each house. On some streets it is on the top of the curb. On our street it is on the vertical portion of the curb. They mark where the sewer and water lines come off the property. Generally the sewer lines run straight off the street. In out case it runs in the courtyard area a few feet away from the garage.

If you want to be really sure, you can contact a plumber or a locating service to verify the location.

If the sewer line does not run in a reasonable position relative to where you want to put the laundry you might want to call the whole thing off. Cutting the concrete floor of the garage and trenching it can be done but it won't be cheap. If you have to cut and trench the floor in a bedroom it will be even worse. :(

In our case, we could run the laundry drain along the back wall of the garage and maintain a proper slope. The inspector required us to box it over which was fine as it makes the installation much less of an eyesore. We have a neighbor that put the laundry area on the side of the garage where the sewer was located and simply ran the drain through the wall then down to the sewer.

Note: They will install a "clean out" above where the laundry line connects to the main "sanitary drain" from the house. In our case that is half hidden in a hedge (that will eventually re-grow) so it is not an eyesore. If you are making the connection in the middle of an atrium (or bedroom) you might not like it.

Note: Not only do you need a drain, you need a vent for the drain. Forget code for a minute: This is a safety issue and the plumbing needs it to work properly. And a vent means a roof penetration. Your plumber should be able to put a vent through a tar and gravel roof and patch it reasonably well. But if you have a foam or rubber membrane roof you will need to coordinate with your roofer.

Running hot and cold water should not be a problem, those pipes can run up hill if they need to, so you can route them which ever way is easiest. And if, like ours, your water heater is in the garage then it is easy to get a place to tap into the pipes.

If/when you pull the permit for this work you will find that Sunnyvale will require both a plumbing and an electrical inspection: Code requires a separate 20 amp circuit for the washer. We were lucky in that we had previously thought of this when we had the electrical upgraded. Running new circuits from your breaker panel could be an issue. If your main electrical panel is full you might need to replace it. The plumber we used for the drain does not do electrical, so you will probably need someone else to deal with that.

Not mentioned in our permit, but the inspector looked anyway, is a proper vent for the dryer. If you locate your laundry area near an exterior wall then that is pretty easy and can be self installed. If you are on an interior wall then you are looking another roof penetration.

If all the above has not scared you off, I can email you the name of the plumber we used. While there were some issues with the job, they stuck with it and did good work and did not charge us for the extra expenses they had incurred.

Tod - that was an interesting and thorough post. Here are two links showing how a new vent is retro-fitted into an existing foam roof. You cut a hole the right size and stick the sheet metal roof jack into a layer of exterior caulk. This is actually easy, inexpensive and should last for decades.
Plumbing vent, electrical or water supply:

http://www.dura-foam.com/PDF/pipe_conduit.pdf

Exhaust vent:

http://www.dura-foam.com/PDF/vent_pen.pdf

TIP: Lint build-up on dryer vents can cause a roof leak. If excess lint builds up and sticks to the vent, it can get wet during rain storms and wick the water down the dryer outlet into your dryer and onto laundry room floor. Be sure to use the lint filter. Check and clean the roof outlet every September. Carefully reach your fingers into the top of the vent and remove lint build-up - if any.