Frost protection of water service line to slab on grade building

[MBGraham]

This concerns a proposed service water line from municipal supply to a residence location that is built on a slab-on-grade. This is in Ontario, Canada with lowest winter temperatures -18F or -27C. I have searched codes but not found answer to my question below:

According to code, water line must be 5ft below grade. Question is - How far under the slab from perimeter wall must line penetrate horizontally before the vertical entry through the slab floor.

Depending on the distance, this could mean the line would be in impractical spot within room. If so, are there any regulations or codes that would allow the vertical line to be closer to the exterior walls?

If this question would be better in a different sub-forum, pleae advise. Thanks

 

[JAE]

Isn't your slab-on-grade below frost at the perimeter? Usually the inside surface of the grade beam has an added insulating layer installed.

 

[MBGraham]

The home was built in 1968 and this room was originally an attached garage. I don't have any slab design details. We are in a limestone area where foundations are often supported off the bedrock, so don't have to be below frost level. Again we don't know if that is the case. We might have to make a preliminary excavation at the entry location to discover what line will have to pass through.

 

[dik]

...as JAE, or can you insulate the pipe?

 

[HTURKAK]

Having experience in cold region, i would say horizontal distance could be 3 -4 feet. You did not mention, if the bldg heated, and and external heat insulation .
You may provide more info ( with pilot excavation ) depth of perimeter footing, heat insulation etc. to get better responds.

 

[MBGraham]

...as JAE, or can you insulate the pipe?

The incoming pipe could be insulated. But will that help? If pipe is out of use for prolonged period wouldn't temperature of earth and water in the line equalize? We probably need to make use of heat from room (it is heated).

 

[MBGraham]

Having experience in cold region, i would say horizontal distance could be 3 -4 feet. You did not mention, if the bldg heated, and and external heat insulation .
You may provide more info ( with pilot excavation ) depth of perimeter footing, heat insulation etc. to get better responds.

3-4 feet was also my guess. It would be better if we could keep that to say 2ft. But if not, we can work with say 5ft. at one entry location. It's not ideal and makes piping from there on a little more difficult.

Regardless of where we decide to enter house, seems I should get contractor to start by excavating to 5+ ft at that point. If no show stoppers, then break out floor of room and try and bore hole(s). Problem I have is that the main excavation contractors for the long line from highway want to sluff off the house entry onto me

 

[JAE]

You can also extend horizontal panels of insulation board out from the bottom of the exterior footing some distance – say three or 4 feet. This is common practice when trying to insulate the perimeter, shallow footings against Frost heave. The idea is that the built-up heat under the house slab will extend out under the horizontal panels of insulation board.

If you did this for a small section, like four or 5 feet along the perimeter of the house, and centered on your pipe, the pipe could extend under the edge of the house, just passed the exterior wall, and turn up. Basically you’re just extending the heat zone out away from the house for a little bit.

 

[MBGraham]

You can also extend horizontal panels of insulation board out from the bottom of the exterior footing some distance – say three or 4 feet. This is common practice when trying to insulate the perimeter, shallow footings against Frost heave. The idea is that the built-up heat under the house slab will extend out under the horizontal panels of insulation board.

If you did this for a small section, like four or 5 feet along the perimeter of the house, and centered on your pipe, the pipe could extend under the edge of the house, just passed the exterior wall, and turn up. Basically you’re just extending the heat zone out away from the house for a little bit.

Thanks. I have read about that type of protection for shallow foundations. As you say, it should also help protect the incoming line if we have to have the riser closer to the outside wall. I would have to pass this by the inspector first.

 

[MBGraham]

We have let the contract. They will use something like JAE's suggestion. Just exactly where insulation will be and how much will be decided once excavation is done. The riser through the slab floor will be about 33" from the inside wall which is about 10" from the outside edge of the slab.

Thanks for the help.