Frost-Retardant manhole lid

[RachelleA]

What is the criteria for determining the need for a frost-retardant manhole lid rather than a regular one? We're in a pretty cold/snowy winter climate.

 

[dicksewerrat]

Sanitary sewers seldom need protection from freezing. Water main MH's may need some. What do you consider a cold climate?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[RachelleA]

We're in southeast Wyoming

 

[dicksewerrat]

I would only worry about the water valve MH's and even then only put plastic pan in them. The pan is sold as a inflow stopper.. Don't plug the center hole, the maint. crew needs that for the main shutdown in case of a main break.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[bimr]

Typically frost proof manholes are used on underground water meter services so the water meter does not freeze. The water meter manhole needs to be waterproof as well.

Some of the water utilities have frost proof manholes in the standard specifications.

 

[civilman72]

The temperature of the ground will generally keep the temperature of sanitary sewer pipes above freezing, but that's assuming you have proper cover over the main.

The only time it might make sense to insulate a sanitary manhole lid is where sanitary mains are installed with less than standard cover, often constructed with foam board trench insulation.

Agree with other comments that it's much more typical to see lid insulation for water system appurtenances.