I know it sounds crazy but I recently noticed that when my washing machine drains, water comes pouring off my roof! The house was built in 1954 and there is a small pipe that sticks out of the roof just above where the washer is. I am sure that this hasn't been happening for the entire year I've lived here. I pours some draino down the washer drain hoping that would cure it but no luck. Any ideas?

I just had to open this post when I read the title. Here is what's happening, probably a combo of two things actually. Washer drain line code was 1.5" back in 54 so its likely your pipe is same for a newer machine. Current code requires a 2' drain pipe and the 2009 code will bring it up to 3" It is also very likely, like 100%, that your main drain line is partiallly plugged. When the washer goes into the drain part of the cycle it pumps water faster than you compromised drains can handle so it backs up the vent stack to the roof. I am totally surprised you aren't seeing showers/tubs back up too as well asevery fixture in the house. Are you sure you don't have any water elsewhere? I sthis washer on the top floor of the house by chance?

Thanks for such a speedy reply! The washer is the very last thing on the water line (or first depending how you look at it). The water from the washer has to go past the kitchen then the bathrooms. The main line comes out from under the bathrooms to the sewer. In the past we had a clog between the kitchen and the main line so when the washer would drain it was filling up the kitchen sink. Also, we had roots blocking the lines (which backed up the bath tubs) because we were told we have old clay pipe running from the house to the sewer. That makes me think the clog must be between the washer and the kitchen sink. Also, the house is only one story and is on pier and beam. We haven't been able to find water anywhere else. Thanks for your help!

You gave the only good explanation and I agree, the clog is downstream of the washer but up stream of eveything else. Rod the drain with a 1/2" snake and you should be good. It is likely lint and some hair.

It's my bet the clog is in the washer branch line. If not you wouldn't be discharging out the roof vent,( This is a first for me). This just has to be one hellava c log to hold back a head pressure that's got to top 8 PSI. rent a sewer snake from a rent place and snake from the washer roof vent. Put out enough cable to reach the base and 20 feet more. CAUTION You have put lye, (Draino) in your system. DO NOT get any of this water on your hands or in your eyes. Good luck, Tom

Tom's right, rod from the roof. While the vent is clear to the roof it is the most direct way of going down the stack, no disconnecting lines or opening clean outs.

Thanks for the advice! My father-in-law has a snake so we'll give it a shot this weekend. I will definitely let you know how it works out. Thanks again.

Well guys, last weekend came and it rained so the roof wasn't very appealing and I put it off. Then, Sunday night, I was doing laundry and went outside and didn't see my usual puddle. I kept an eye on it all week and it is not draining through the roof anymore. I guess the Draino I used finally worked through the clog? Anyway, it seems the problem has been solved. Thanks so much for your help and advice. If the problem comes up again I will definitely try it.
Thanks again, Susana :)

We're happy that you don't see the washer discharging out the roof vent. Got to be one hellava clog to back the water up that far, but then washer pumps are m ore powerful nowadays. If we can ever be of assistance just ring our chimes. Regards, tom