PVC for water?

[bforeman]

Ran across PVC line used for water distribution. Is this allowed? I know CPVC is used. What's up?

[Joe Funderburk, CMI]

This is what I say:

"The house contains Polyvinyl Chloride (PVC) pipes for the cold water supply. The use of PVC is prohibited by today's standards in new construction for use as water distribution piping within the dwelling and we recommend that you consult with a competent and licensed plumbing contractor about the use of such material in this home."

[bforeman]

Thanks Joe.

[Brent Potter]

It's been my experience that PVC is allowed for cold water distribution. PVC is not listed for hot water. Your local juristiction will tell you what is allowed.

[Joe Funderburk, CMI]

PVC is listed in the current IRC Table 2904.4.

"P2904.4 Water service pipe. Water service pipe shall conform
to NSF 61 and shall conform to one of the standards listed in
Table P2904.4. Water service pipe or tubing, installed underground
and outside of the structure, shall have a minimum
working pressure rating of 160 pounds per square inch at 73°F
(1103 kPa at 23°C). Where the water pressure exceeds 160
pounds per square inch (1103 kPa), piping material shall have a
rated working pressure equal to or greater than the highest
available pressure. Water service piping materials not
third-party certified for water distribution shall terminate at or
before the full open valve located at the entrance to the structure.
Ductile iron water service piping shall be cement mortar
lined in accordance with AWWA C104."

PVC is not listed in the current IRC Table P2904.5 quoted below. I underlined "dwelling units" as that stands out to me as the main difference between the two tables.

"P2904.5 Water-distribution pipe. Water-distribution piping
within dwelling units shall conform to NSF 61 and shall conform
to one of the standards listed in Table P2904.5. All
hot-water-distribution pipe and tubing shall have a minimum
pressure rating of 100 psi at 180°F (689 kPa at 82°C).

WATER DISTRIBUTION PIPE
MATERIAL STANDARD

Brass pipe ASTM B 43

Chlorinated polyvinyl chloride (CPVC) plastic pipe and tubing ASTM D 2846; ASTM F 441; ASTM F 442; CSA B137.6

Copper or copper-alloy pipe ASTM B 42; ASTM B 302

Copper or copper-alloy tubing (Type K, WK, L, WL, M or WM) ASTM B 75; ASTM B 88; ASTM B 251; ASTM B 447

Cross-linked polyethylene (PEX) plastic tubing ASTM F 877; CSA B137.5

Cross-linked polyethylene/aluminum/cross-linked polyethylene
(PEX-AL-PEX) pipe ASTM F 1281; CSACAN/CSA-B137.10

Cross-linked polyethylene/aluminum/high-density polyethylene
(PEX-AL-HDPE) ASTM F 1986

Galvanized steel pipe ASTM A 53

Polybutylene (PB) plastic pipe and tubing ASTM D 3309; CSA CAN3-B137.8

Polyethylene/aluminum/polyethylene (PE-AL-PE) composite pipe ASTM F 1282

Polypropylene (PP) plastic pipe or tubing ASTM F 2389; CSA B137.11

Stainless steel (Type 304/304L) pipe ASTM A 312; ASTM A 778

Stainless steel (Type 316/316L) pipe ASTM A 312; ASTM A 778
TABLE P2904.6"

[Bruce A. King]

This has been covered before, the reason its not allowed for cold water is the difficulty in verifying that it is only installed for the cold water during the AHJ's 3-5 minute walk through during a rough in inspection.

[Joe Funderburk, CMI]

Bruce, can you enlighten me...what is the distinction between the two tables I referenced above. One allows PVC, the other does not.

[Bruce A. King]

I admit, I didn't study the tables...

I just remember that the use of PVC water piping is typically controlled by the local AHJ's (code amendment maybe?) and I believe none allow it for the reason I posted above, difficulty in knowing if it is only on the cold side within the house so they just don't allow it at all even if the code does.

[jschulte]

The top is for the water service, which is not heated. The lower is for the distribution pipes which can be heated. PVC is not rated for hot water.

[Joe Funderburk, CMI]

Originally Posted by jschulte

The top is for the water service, which is not heated. The lower is for the distribution pipes which can be heated. PVC is not rated for hot water.

I don't think that is correct. Upon further digging into it, I find that the IRC defines water service piping as follows:

"WATER-SERVICE PIPE. The outside pipe from the water main or other source of potable water supply to the water-distribution system inside the building, terminating at the service valve."

That means the piping prior to entry into the house, and that is what the first table refers to.

The IRC defines distribution piping as follows:

"WATER-DISTRIBUTION SYSTEM. Piping which conveys water from the service to the plumbing fixtures, appliances, appurtenances, equipment, devices or other systems served, including fittings and control valves."

That means all piping in the house, whether hot or cold, and that is what the 2nd table refers to.

Therefore, according to the tables, PVC is no longer allowed by the IRC for either hot or cold water distribution piping.

[jschulte]

I am not arguing that PVC is allowed as distribution plumbing in the house. I am telling you the difference in the tables. As far as I am concerned, I would recommend removal of the PVC.

Also, the service line does enter the house, it just doesn't go very far. So, you could have some PVC, as long as it ends at the service valve.

[Joe Funderburk, CMI]

I misunderstood you, but now I'm clear and we agree. Thanks Jeff.