# Does a waste line connecting to sewer line have to be underground?



## SJP415 (Aug 19, 2018)

Hi all - we are about to start a project where we are converting our detached garage into a mother-in-law unit and adding a new bathroom with a shower, sink and toilet in it. The new bathroom will need to connect to the main sewer line and have a waste line/drain line (_not sure what the right terminology is here sorry - I'm talking about the new pipe line that connects the new toilet to the main sewer line_). The question is *does this new line that will connect to the main sewer line have to be buried underground*? We have gotten conflicting information from two plumbers: one said no it can just run under our deck as long as it has the right slope and it's not exposed to the sun; the other said it had to be underground and we would have to dig a trench. We live in San Diego so no frost worries here. It would cost a lot more to have to put it underground so just wondering if anyone knows if there is a code requirement that says it has to go underground? We can easily hide it under our deck to keep it away from sun exposure. Thank you!


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## mark handler (Aug 19, 2018)

It needs to be protected, and uniformity supported. It also needs to have accessable cleanouts and have proper slope.


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## cda (Aug 19, 2018)

Interesting  no burial required?

Try an anonymous call to the city to check also.


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## ICE (Aug 19, 2018)

On the topic of protection: I was told that the only ABS that is allowed to be exposed to sunlight is that bit above the roof.  That bit must be painted.  All other, including cleanouts, is not allowed to be exposed to sunlight with or without paint.

That was at a ICC accredited training class.  When I questioned that I was informed that the manufacturer's installation instructions require it.

Then I found this:
312.13 Exposed ABS Piping. ABS piping shall not be exposed to direct sunlight.
Exception: ABS piping exposed to sunlight that is protected by water based synthetic latex paints.


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## north star (Aug 20, 2018)

% * %

Maybe we should clarify exactly what type of pipe
***SJP415*** is referring to.......ABS, ...PVC,
or something else.

Also, ...the 2016 CPC, Section 312.3 requires a minimum of
12 inches depth of the building sewer.

*% * %*


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## mark handler (Aug 20, 2018)

That section says "..materials other than those approved for use ..."
If the material are approved, they donot need to be 12-inches below.

How many raised floor houses havd you seen with the sewer line strapped to the underside of the joists, not buried 12-inches below  grade.
Most sewer under slabs or in structures are not 12 to 24 inches below the slab..


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## north star (Aug 21, 2018)

*% = %*

Thank you for the correction Mark !  

*% = %*


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## Keystone (Aug 21, 2018)

Charolette Pipe allows non pressure schedule 40 PVC to be installed exposed to direct sunlight if the pipe covered with water based latex paint


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## JBI (Aug 21, 2018)

mark handler said:


> That section says "..materials other than those approved for use ..."
> If the material are approved, they donot need to be 12-inches below.
> 
> How many raised floor houses havd youseen with the sewer line strapped to the underside ofthe joists, noht buried 12-inches below  grade.
> Most sewer under slabs or in structures are not 12 to 24 inches below the slab..



Within the building it is a building drain NOT a building sewer line... the building drain is not exposed to direct sunlight.


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## mark handler (Aug 21, 2018)

JBI said:


> Within the building it is a building drain NOT a building sewer line... the building drain is not exposed to direct sunlight.


*Read the original post*


> "....no it can just run under our deck as long as it has the right slope and it's not exposed to the sun..."



*Same thing, it does not need to be underground.*


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## JBI (Aug 21, 2018)

mark, we can agree to disagree I suppose...


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