Latest Discussions : HVAC


04:08PM | 03/04/03
Member Since: 01/13/03
3 lifetime posts
My sump pump discharge piping exits through my foundation and remains above ground for about 1.5 ft before going underground again where it joins with other PVC pipes. The exposed piping is 3" in diameter.

During the cold winter, the water in my PVC pipe froze. I wrapped a single layer of polyethylene foam insulation around the pipe, but the insulation was not enough. The pipe froze again.

Does anybody have any recommendations on what to use to effectively insulate this pipe?

I have a check valve in the discharge piping, so I assume that when the pump shuts off the exposed section is still full of water. Otherwise, I wouldn't think it would freeze. I believe the check valve prevents the water from draining back down into the sump hole when the pump shuts off.

Thanks in advance.

Jay J

04:15PM | 03/06/03
Member Since: 10/26/00
782 lifetime posts
Hi candc,

Well, the water is freezing because you probably don't have sufficient slopage in the line that exits the foundation. If it's steep enough, it should run through. If you can't improve the slopage, you do have a problem.

My best to ya and hope this helps.

Jay J -Moderator

PS: God Bless America!


01:10PM | 03/11/03
Member Since: 10/15/02
359 lifetime posts
You might want to put a couple shut offs and tie it into your house drain for when it gets really cold out. I have my main sump tied into the septic for just that reason, but fortunatly havent had a need to switch to the septic side.


03:37PM | 03/11/03
Member Since: 01/13/03
3 lifetime posts
Dear Jay J,

I agree with your comment that my PVC pipe shouldn't freeze if there is not water in it. Actually, I'm not sure why it is freezing at all, but I've poured water on it twice and that got the water pumping again.

As far as the piping arrangement, the pump is in the basement and pumps vertically, through a check valve up to the foundation level. It exits the foundation horizontally and protrudes from the foundation wall by about 6". It then makes a right angle downward. About 1.5 feet of pipe is visible before it submerges underground. The pipe is then gently slopes as it extends about 20' horizontally from the house.

Due to the check valve in the vertical section in the basement, I'm sure there is water in that part of the line when the pump shuts off. However, there shouldn't be water in the section that sticks out of the house. Without looking as I write this (its dark), my guess is that the horizontal section that protrudes from the house is somewhat sloped back toward the house. It's that horizontal section that freezes. If I can somehow, slope that horizontal section away from the house, then whatever water is in that horizontal section should drain away from the house.

Thanks for giving me the idea to check this.


09:33AM | 06/05/20
Will sch 40 pvc conduit for electric wiring freeze and crack with winter temperatures?

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