joshuabardwell
Elite Member
When you are running a line like this how deep do you go to keep the water line from freezing, your frost depth?
Consult with a local plumber. Codes vary. You always want it at least as deep as your frost line, plus a safety margin. Code may have a different idea of what is required, and the inspector (if it is ever inspected) may have a different idea still. Here is what a neighbor of mine, who is a plumber, said when I asked him a similar question:
Most local building authorities require 18" depth on water lines. However, if you look at the charts in the building code books the frost line for this area is about 11", but the minimum frost line requirement for any location is 12". However, a 6" buffer or margin of safety is usually required, thus ending up at 18" here. When I was a plumbing inspector for the City of Knoxville there was always lots of discussion on this matter and most times it was somewhat discretionary on the part of the inspector when rocky ground or other problems arose. I can tell you from experience that I hardly ever see an underground water line freeze around here anymore, and we've seen quite a few that are as shallow as 10"-12". Personally, we try to always install a new water line at 15"-18" and that is the depth I would use on my own line as well.