View Full Version : Garage drain in freeze-prone areas
09-25-2005, 07:41 PM
Here's a question I haven't seen answered before: What keeps the trap water in a floor drain in a garage from freezing in cold weather? Any special plumbing requirements to putting in such a drain?
09-25-2005, 08:39 PM
The more shallow the trap, the more prone it would be to freezing. If the lateral leading to this trap is significantly low, you can make the turn up for the trap long. This will deepen how far the trap is in the ground, the less likely to freeze. Good mother earth is it's protection, especially over a covered structure to boot.
09-25-2005, 08:39 PM
You have two choices. If it's a sink trap, you can remove the trap and plug the remaining drain to keep sewer gas out or you can leave the trap in plane and pour RV anti freeze into it. Note it's RV anti freeze, not automobile. For a toilet, I'd plunge, dip, and sponge as much water out as possible then fill with RV anti freeze. Be sure to get all of the water out of the tank, and don't forget the supply line between the tank and cut off valve.
09-25-2005, 08:46 PM
I built a garage a couple of years ago on a budget. I wanted to have a place for the water to drain, but didnít want to worry about the plumbing of a drain. I created a simple shallow sump. The sump is about eighteen inches wide, thirty-six inches long, and about twelve inches deep. I live in North Dakota and we get a lot of cold weather and snow. This sump works really well. I put a four x four timber in during the winter to help absorb the force of the freezing water and I am quite happy with it. I have a two stall garage and I put it under one of the stalls so that I did not have to walk on it all the time. I bucket out the water in the spring and everything is great.
09-26-2005, 04:45 PM
Thanks, everyone, for your responses! I'm thinking ahead to when I (maybe!) eventually build my next house. One of my wish list items would be to have hot and cold water in the garage and some sort of drain to allow me to hose off a car in winter. Come to think of it, if I were doing this, I'd need to heat the garage, at least while washing the car, so the freezing issue would be temporarily moot.
I like Rugged's idea of burying the trap deep to take advantage of soil temperatures! Makes sense.
For just collecting snow melt, etc., the sump idea of neili's makes good sense, too.
Thanks, Gary, for the tip about RV antifreeze. I'm assuming it's less toxic to dogs and cats than auto antifreeze?
09-26-2005, 08:30 PM
Because all sorts of nasty gunk can run into a floor drain in the garage, you need to take care that it actually drains somewhere safe. It can contain heavy metals, antifreeze, oil, gas, salt, etc. in addition to the snowmelt, and soapy water. Not great for either a septic system, or a regular sewer, but the dilution of a regular sewer can handle it better. There may be special codes in your town regarding this...my unprofessional opinion.
09-27-2005, 03:52 AM
Good point! Thanks for that tip, Jim.