Sewer Valves

Many people in Oak Park, a suburb of Chicago, are installing sewer valves for their homes. Some years back we had an impressive deluge and this is a reaction. Your stack or stand pipe may drain directly out to the street sewer. Putting a check valve or flapper in the way means that when the system hits load those houses refuse service and the overall pressure on the system will increase precisely at the time it is stressed. If you don’t have a flap then super tough on you, the effluent has to go somewhere. A product that creates its market. Once everyone has flaps there should be popped flaps or broken pipes.

Flaps are necessary on flood plains. As flood plain construction is common it is difficult for other municipalities, such as Oak Park, to deny their use. Chicago used to require a basement floor drain. You were expected to share your suffering with your neighbors.

Most people have their stack drain into their own sewer that then drains into the street sewer. This is a nice feature that gives the system some bounce and durability. Typically, however, the new flap is inserted between the two sewers. This creates the same shock on the system as above. I think the next deluge will disappoint those homeowners. As I remember it, I heard the sewer cover on the home sewer bounce. There was, for a moment, about a foot of water in the yard. It was the yards’ water coming into the home sewer that went up the stack and flooded the basement. Blocking the street sewer alone will not protect your basement. Maybe a sewer lid gasket on your sewer along with the flapper would work. But then it wouldn’t take the normal drain from your yard, increasing the chance of seepage.

It would be better to place the flap between the home and the home sewer. This would give the street system some bounce and also protect your basement, if not your yard. Unfortunately, if you examine your sewer, you will see that this is a deep connection. At that depth the pressure might overwhelm the flap. If you do not mind advertising that your house floods, you could break through your foundation to put the flap near the stack. Might as well put in the sump pump while you are there.

While you may disdain allowing the sewer unfettered access to your home, consider placing the flap between the stack and basement source. The flap would deny sewer water the exit of your basement without threatening system integrity. Water seeks its level; it can’t go higher in your house than it is outside. It’s just a matter of boundaries. Again, you will have to break the foundation.

The real secret of the Victorians was their plumbing. Failing all else perhaps install a new water closet somewhere upstairs, move the washer and drier up there as well, close off the basement plumbing and then you won’t need a flapper.