plumbing drain depth

[Anthony Alderman]

Is there a minimum depth for a sewer line leaving the house?? Client called because contractor was putting in a runoff drain around the house and cut the sewer line that was 4 inch's under the soil. seems a little shallow even in NC

[John Arnold]

I don't know the answer, but I like your new avatar. It reminds me of my current favorite tv show, Breaking Bad.

[Anthony Alderman]

Thanks,
my grand kids love it. They say I kind of look like a character on one of their WII games. :)

[brian schmitt]

anthony,
a minimum off 12" in the u.p.c. section 720. what is the frost depth?

[Anthony Alderman]

Finally talked to my plumber....
heir is the deal:
Supply is min 12" and 6" below frost line,
Wast, which is what I was looking for, is 3" of covering

[Jerry Peck]

Is there a minimum depth for a sewer line leaving the house?


- P2603.6 Freezing. In localities having a winter design temperature of 32°F (0°C) or lower as shown in Table R301.2(1) of this code, a water, soil or waste pipe shall not be installed outside of a building, in exterior walls, in attics or crawl spaces, or in any other place subjected to freezing temperature unless adequate provision is made to protect it from freezing by insulation or heat or both. Water service pipe shall be installed not less than 12 inches (305 mm) deep and not less than 6 inches (152 mm) below the frost line.
- - P2603.6.1 Sewer depth. Building sewers that connect to private sewage disposal systems shall be a minimum of [NUMBER] inches (mm) below finished grade at the point of septic tank connection. Building sewers shall be a minimum of [NUMBER] inches (mm) below grade.

The "[NUMBER]" is what the Building Official is supposed to fill in based on frost depth, however, being as (according to you NC guys) the AHJ does not enforce the protection from freezing it is unlikely the AHJ has entered any number there either.

The sewer depth "should be" a minimum of 12 inches below the frost depth, and when there is no frost depth stated the depth "should be" 12 inches minimum. Of course, that also needs to be (unless there is a basement) below the bottom of the footing which has a relieving arch in it and the bottom of the footing "should be" a minimum of 12 inches below the frost depth or a minimum of 12 inches where no frost depth is given, which means the sewer pipe "should be" below 12 inches minimum.

[James Duffin]

NC Plumbing Code Admendents

305.6 Freezing.

The top of water pipes, installed below grade outside the building, shall be below the frost line or a minimum of 12 inches below finished grade whichever is greater. Water pipes installed in a wall exposed to the exterior shall be located on the heated side of the wall insulation. Water piping installed in an unconditioned attic or unconditioned utility room shall be insulated with an insulation having a minimum R factor of 6.5 determined at 75oF in accordance with ASTM C-177.

NOTE: These provisions are minimum requirements which have been found suitable for normal weather conditions. Abnormally low temperatures for extended periods may require additional provisions to prevent freezing.


305.6.1 Frost protection.
No traps of soil or waste pipe shall be installed or permitted outside of a building, or concealed in outside walls or in any place where they may be subjected to freezing temperatures, unless adequate provision is made to protect them from freezing. Waste and soil piping leaving the building shall have a minimum cover of 3 inches.

[Jerry Peck]

Waste and soil piping leaving the building shall have a minimum cover of 3 inches.

James,

Based on the rest of the code you posted, that "minimum cover of 3 inches" applies only to warm days. :D

[James Duffin]

I didn't write it......only shared it. ;)

[Anthony Alderman]

AHJ in the triangle thinks it's always warm :)