Does HDPE pipe above water line reduce ground insulation ability?

[Nic3456]

Running 2"PVC water line about 40" deep

At one point a 12" HDPE drain pipe( part of field tile system) runs ~4 inches above the water line

Do I need to worry about increased freezing risk of water line? (Wasn't sure if the HDPE pipe increased/decreased or no impact on ground insulation.

This is in central Ohio where water company recommends 36-48" bury depth.

 

[Gary Fowler]

I would think that since it is a dead air space in the field tile 12" pipe that it would increase the insulation factor, after all insulation is nothing but a dead air space.

 

[bigdeano]

12" is big enough to let the air circulate due to convection, which would transfer the cold to the bottom of the pipe. Just a theory on my part. Can you put a piece of styrofoam insulation in between?

 

[Redlands Okie]

12" is big enough to let the air circulate due to convection, which would transfer the cold to the bottom of the pipe. Just a theory on my part. Can you put a piece of styrofoam insulation in between?

Closed cell foam, i like this idea need to go past the area in question a ways of course.

 

[Nic3456]

Thanks for the tips - will give insulation a try

 

[LD1]

No need to worry. Especially if you are burying at least 36" deep. Frost depth in our area is only ~24".

When doing field tile, I have uncovered delco lines with only ~12" of soil on top of them. Techs in the field kinda joked that as long as it has a few inches of dirt over it, its good.

Where in the stages of this process are you now? Trench open? Line laid?

Did you ever contact delco and get an understanding of how their tap fees and meter fees work? And decide what size tap/meter you will be using?

 

[PILOON]

Closed cell foam, i like this idea need to go past the area in question a ways of course.

Around here 48" is frost level and I have successfully insulated water intakes using 16" wide dense foam (blue or pink) over water intake lines with a mere 12" or even less of soil coverage.
The intake never froze in 12 yrs, so it works.
Locals also used 12" wide hemlock boards to the same results but left the tap slightly open as running water won't freeze.
Instructions were to never walk on the water line so as to not compact the snow cover. (Fluffy snow also insulates to an extent.)

 

[TemporaryKubotaOwnerMark]

12" is big enough to let the air circulate due to convection, which would transfer the cold to the bottom of the pipe.

Cold does not transfer. Heat transfers. In this case, convection would transfer heat AWAY from the buried pipe.

 

[Cord]

It's been shown that sewer pipes do cause the frost to drive deeper. That said, those pipes are significantly larger than your culvert. It's probably not a problem but if you're really concerned just throw a couple sheets of 1" XPS insulation down at the intersection. Put the foam down in two layers, each layer offset to cover the joints. This is the same solution that's applied to municipal pipe crossings.