PVC Irrigation Piping in Foundation Crawlspace

**Gunnar Alquist** · 11-10-2015, 07:01 PM

So... this is PVC sprinkler/irrigation supply piping under a house. It does not supply domestic water to the house, but runs from automatic irrigation valves to drip irrigation at the exterior. CPC says PVC is not OK for distribution pipe or fittings but OK for building supply pipe and fittings (CPC T-604.1).

In this particular case, water in the PVC piping is under intermittent pressure and, as stated above, is not for household distribution. My understanding is that PVC is OK for pressure outside the building envelope, drain piping within the building envelope but not for pressure/distribution within the building envelope and I should not see PVC in the foundation crawlspace area unless it is a drain pipe. My problem is that I am not able to find the specific code that states this. California is using the 2013 California Plumbing Code, which is essentially a modified 2012 UPC.

Can someone direct me to the correct reference?

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**Gunnar Alquist** · 11-10-2015, 07:31 PM

Oh wait, is this it?

From:
Installation Standard For PVC Cold Water Building Supply and Yard Piping
IAPMO IS 8-2006

2.7 Material.
2.7.1 Location.
PVC piping shall be installed only
outside the foundation of any building or
structure or parts thereof. It shall be buried in
the for its entire length except vertical
piping may be extended above grade per
Section 2.4.4. It shall not be installed within
or under any building or structure or mobile
home or commercial coach or parts thereof.
The term "building or structure or parts
thereof" shaH include structures such as
porches and steps, whether roofed or not,
roofed porte-cocheres, roofed patios, carports,
covered walks, covered driveways and simi lar
structures or appurtenances. [UPC 604.1]

**Jerry Peck** · 11-10-2015, 07:36 PM

Originally Posted by Gunnar Alquist

My understanding is that PVC is OK for pressure outside the building envelope, drain piping within the building envelope but not for pressure/distribution within the building envelope and I should not see PVC in the foundation crawlspace area unless it is a drain pipe.

You will likely not find a specific section which prohibits that as using PVC within the footprint of the house is basically not permitted.

PVC is permitted for water service pipe to the service valve, which is outside the point of entry, beyond that would be piping which is not water service pipe and would thus be required to be CPVC.

The INTENT of the code is to not have pressurized PVC (DWV is okay) inside the footprint of the structure because PVC is subject to breakage and thus leakage, thus, regardless of the water contained in the PVC, one would not want pressurized PVC within the footprint of the structure.

The does not, and cannot, attempt to address all aspects of what some stupid idiot (yes, I did say stupid idiot to make sure that I included both those who are "stupid" and those who are just plain "idiots") might or might not do.

You are correct in that pressurized PVC used for ANY purpose should not be in the crawlspace.

Finding a code section which specifically addresses that stupidity is unlikely - I would use the code section which permits PVC for water service outside the structure up to the service valve, then requires a material which is on the branch piping material list as the reason and intent of the code to not allow pressurized PVC within the footprint of the structure.

If anyone resists, tell them to get a letter from the AHJ which specifically states that PVC piping for that pressurized use is permitted in that AHJ and have it signed by the Building Official AND the AHJ attorney (so the attorney will have a heads up as to what the Building Official is allowing - after all, it is that attorney who will be defending that Building Official when the lawsuit is filed and the Building Official becomes a defendant as the Building Official and personally.

- - - Updated - - -

Originally Posted by Gunnar Alquist

Oh wait, is this it?

From:
Installation Standard For PVC Cold Water Building Supply and Yard Piping
IAPMO IS 8-2006

2.7 Material.
2.7.1 Location.
PVC piping shall be installed only
outside the foundation of any building or
structure or parts thereof. It shall be buried in
the for its entire length except vertical
piping may be extended above grade per
Section 2.4.4. It shall not be installed within
or under any building or structure or mobile
home or commercial coach or parts thereof.
The term "building or structure or parts
thereof" shaH include structures such as
porches and steps, whether roofed or not,
roofed porte-cocheres, roofed patios, carports,
covered walks, covered driveways and simi lar
structures or appurtenances. [UPC 604.1]

Yes! Dang it, you found it while I was looking for it, gave up on it and typed my reply.