Placement of cold water line under slab on grade.

[RaidersFan]

Hello,
My question is about the where to put the cold water line. I am building a home with a slab on grade. I am putting in radiant heat and have 2" of rigid foam under the slab. I am running the hot water supply above the insulation. Should I run the cold water supply under or above the insulation?

Thanks in advance.

 

[Shibby021]

I am in process of doing mine right now, I will be running both cold and hot line under the slab. I also have 2 inch rigid foam and will be doing radiant heat as well too. My friend next door has the same setup built in 2020, works out well minus the 2nd bathroom which is like about 70 to 80 ft from the hot water tank, it takes quite a while to get the hot water there! But that setup works well even when it's minus 30 for a week!

I want to add we also have 2 inch rigid foam extending 2 feet vertically around the slab.

 

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[John Gayewski]

I would run my cold water line under the insulation and deeper to try to keep it cold.

 

[RaidersFan]

I am in process of doing mine right now, I will be running both cold and hot line under the slab. I also have 2 inch rigid foam and will be doing radiant heat as well too. My friend next door has the same setup built in 2020, works out well minus the 2nd bathroom which is like about 70 to 80 ft from the hot water tank, it takes quite a while to get the hot water there! But that setup works well even when it's minus 30 for a week!

I want to add we also have 2 inch rigid foam extending 2 feet vertically around the slab.

Hi Shibby021.
Thanks for the reply. So you are running both hot and cold under the slab. I am also. Are you running the cold under the 2” rigid foam or above it?

 

[RaidersFan]

I would run my cold water line under the insulation and deeper to try to keep it cold.

Hi John. Thanks for the reply. I’m thinking of running the cold under the insulation for the same reason.

 

[Shibby021]

Hi Shibby021.
Thanks for the reply. So you are running both hot and cold under the slab. I am also. Are you running the cold under the 2” rigid foam or above it

under the foam, 6 inches in the dirt.