can a waterline cross a sewer line?
#1
03-31-16, 04:27 PM
Join Date: Mar 2013
Posts: 38
Upvotes: 0
Received 0 Upvotes
on
0 Posts
can a waterline cross a sewer line?
Ok. I have to do a re-pipe of my sewer. The ONLY place i can put my sewer line is a place where it will be crossed by my main water supply line. The waterline is 3/4 pex and the sewer line i am planning to use are sch 40 pvc. Is this in code compliance?
#2
03-31-16, 04:43 PM
Not familiar with actual codes, but my starting place would be your local permit/code office, since the buck starts and stops there. Not only will they know the code, but they will know when an exception might be needed. They are good folks to get to know.
Bud
Bud
#3
03-31-16, 05:19 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes
on
30 Posts
We would all be in a world of hurt if water piping was not allowed to cross sewer piping. There ARE, however, certain minimum vertical distances that must be observed.
Bud has the right idea, call the LOCAL permitting office and ask them. You have to call the local office because "codes" are merely recommendations until enacted into law by a legislative body. The enabling legislation has the power to add to or delete from the "model" code so what is code for me may be different for you.
Bud has the right idea, call the LOCAL permitting office and ask them. You have to call the local office because "codes" are merely recommendations until enacted into law by a legislative body. The enabling legislation has the power to add to or delete from the "model" code so what is code for me may be different for you.
#5
03-31-16, 10:30 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes
on
30 Posts
Very simply, the vertical distance from the top of the lower pipe to the bottom of the upper pipe. It MAY be as little as three or four inches or it MAY be as much as a foot or more. I don't know what is required in YOUR jurisdiction. Some jurisdictions may require different distances depending on whether the sewer piping is above or below the water piping.
Here is a Google search that may help you. In Washington state the separation requirement is 18 inches and the sewer piping must be the lower pipe.
Here is a Google search that may help you. In Washington state the separation requirement is 18 inches and the sewer piping must be the lower pipe.
#6
04-01-16, 07:55 AM
Group Moderator
You most likely need to get a permit for this work. So, while getting the permit just ask them what they want to see.
It is recommended that there be 10' lateral separation but 5' is permitted if the soil between is not disturbed. Then a private water line can be located in the same trench with a sewer line if the bottom of the water line is 12" above the top of the sewer line. And finally all that is thrown out if the sewer line is made of an approved material. Crossing is a different situation. Basically there are a number of bits to the code so it can sometimes come down to what your local inspectors enforce and want to see. In the end it is permitted but you'd better do it in a manner that your inspectors like. In my city a PEX water line is permitted to cross a schedule 40 PVC sewer line. Some inspectors want to see the water line sleeved where is crosses the sewer. Other inspectors... not so much.
It is recommended that there be 10' lateral separation but 5' is permitted if the soil between is not disturbed. Then a private water line can be located in the same trench with a sewer line if the bottom of the water line is 12" above the top of the sewer line. And finally all that is thrown out if the sewer line is made of an approved material. Crossing is a different situation. Basically there are a number of bits to the code so it can sometimes come down to what your local inspectors enforce and want to see. In the end it is permitted but you'd better do it in a manner that your inspectors like. In my city a PEX water line is permitted to cross a schedule 40 PVC sewer line. Some inspectors want to see the water line sleeved where is crosses the sewer. Other inspectors... not so much.
#7
04-01-16, 10:46 AM
Join Date: Mar 2013
Posts: 38
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Thanks guys. Also, how many times does code allow for a pipe to turn? I know I am going to have to make at least 3 turns to get around various obstacles (trees, etc). Can a pipe tunnel under a footing? Can it run under a dirt driveway?
#8
04-01-16, 11:09 AM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes
on
30 Posts
I am unaware of any code requirements limiting the number of bends or turns in water supply piping. There MAY be such limitations but I have never come across them. Sewer piping DOES have minimum radii for bends based upon the pipe diameter but I am not aware of any maximum number of degrees of bend as there is with electrical conduit.
Sewer piping also has minimum "fall" or "drop" requirements, generally a continuous slope of no less than 1/8 inch per foot and no more than 1/4 inch per foot in the direction of flow. Too little fall and the pipe won't drain and too much fall will often leave solid waste "high and dry" as the liquid drains too quickly.
Sewer pipe diameter is based upon the number of "fixture units" connected to the piping. A fixture unit is a standard plumbing term denoting the expected waste flow through any connected sink, shower, tub, floor drain, toilet, etc. Using too small a pipe will cause clogs and back-ups while using too large a pipe will again leave solids behind as the liquids drain too fast.
Sewer piping also has minimum "fall" or "drop" requirements, generally a continuous slope of no less than 1/8 inch per foot and no more than 1/4 inch per foot in the direction of flow. Too little fall and the pipe won't drain and too much fall will often leave solid waste "high and dry" as the liquid drains too quickly.
Sewer pipe diameter is based upon the number of "fixture units" connected to the piping. A fixture unit is a standard plumbing term denoting the expected waste flow through any connected sink, shower, tub, floor drain, toilet, etc. Using too small a pipe will cause clogs and back-ups while using too large a pipe will again leave solids behind as the liquids drain too fast.
