ABS versus PVC for DWV

[JPMacG]

I'm not an inspector, just a Harry the Homeowner. I have been lurking for a year or more and have learned a lot from this forum.... thank you all!

Maybe someone can clear up a curiosity of mine. The use of ABS versus PVC for DWV plumbing seems to be a regional thing. Depending where one lives, either ABS or PVC is required, but exclusively one or the other. From what I have read it seems that either is satisfactory from a functional standpoint. There are arguably some slight advantages to PVC.

Does anyone care to speculate why the rules are written to allow one or the other but not both? Why does my township require that I use ABS and not PVC? I'm not talking about mixing ABS and PVC in the same house. Why do they restrict me to ABS when PVC would be equally functional? It seems that they are being unnecessarily restrictive.

[Bill Kibbel]

What township in Bucks County REQUIRES ABS?

[JPMacG]

I do live in Bucks County and my township does specify PVC for new work. My question is more general in nature. I was recently visiting a relative in the Tucson Arizona area, where they seem to use ABS exclusively.

Just wondering why one material is chosen and the other is excluded. Why not accept both?

[plummen]

Id say it depends a lot on who was on the local plumbing board when the rules were written,and which material they prefered.

It could be worse ,if you had a bunch of union plumbers on the board you could of been required to use all cast iron pipe and dwv copper for all your waste/vent piping in your house! [:-spin]

[hausdok]

Hi

Around here it doesn't make any difference. ABS is king due to cost but I've seen plenty of PVC as well.

ONE TEAM - ONE FIGHT!!!

Mike

[Marc]

I've heard that a major player in ABS vs PVC was that ABS emits toxic fumes when it burns.

Marc

[kurt]

So does PVC......the fumes will kill you.

It's important to understand that building codes are not engineering documents. They are cobbled together from multitudes of competing theories, market forces, engineering both accurate and inaccurate, industry lobbying, marketing campaigns, personal bias and proclivity, labor union muscle, regional variables, etc., etc.,........

So, no good reason. PVC won the big market through lots of forces.

[plummen]

So does PVC......the fumes will kill you.

It's important to understand that building codes are not engineering documents. They are cobbled together from multitudes of competing theories, market forces, engineering both accurate and inaccurate, industry lobbying, marketing campaigns, personal bias and proclivity, labor union muscle, regional variables, etc., etc.,........

So, no good reason. PVC won the big market through lots of forces.

What he said!

[Jim Katen]

I suspect that the question is without foundation. In most of the places where you see exclusive use of ABS or PVC, it's because of custom, not regulation. Both the UPC and the IRC allow either one.

Can anyone cite an actual code or rule that excludes one or the other?

[JPMacG]

I cannot cite the code, but I have been told by a local plumber that PVC must be used for new work in this area (Bucks County, southeastern PA). I informally confirmed this with a different plumber at my place of employment. So I think it is likely correct.

As for Tucson, I have observed that only ABS is used, but I don't know if this is code.

Thanks for responding to my question.

[Bill Kibbel]

In your first post you state:

"Why does my township require that I use ABS and not PVC?"

Now you state:

"I cannot cite the code, but I have been told by a local plumber that PVC must be used for new work in this area (Bucks County, southeastern PA). I informally confirmed this with a different plumber at my place of employment. So I think it is likely correct."

Bucks County does not enforce building codes - it's the responsibility of the individual local municipalities (towns & townships). I don't know of a single township in Bucks County that requires "PVC must be used for new work". In fact, ABS, copper, galvanized steel, polyolefin and cast-iron are permitted by code. Add to that list brass and stainless steel. The only restriction is that you can't install galvanized wrought-iron or galvanized steel pipe below grade anymore.

Please ask your plumbers which municipalities only allow PVC.

[Jim Katen]

I cannot cite the code, but I have been told by a local plumber that PVC must be used for new work in this area (Bucks County, southeastern PA). I informally confirmed this with a different plumber at my place of employment. So I think it is likely correct.

Nah. Not really. The trades are full of folklore that just isn't true. If you asked 10 plumbers in my area, half of them would probably say that PVC isn't allowed. They'd be wrong.

If you want to know what the code says, you have to look at the code.

[rjbrown2]

PVC compounds, in general, are among the more fire resistant common

organic polymers, natural or synthetic. The major products of thermal decomposition include hydrogen chloride,

benzene and unsaturated hydrocarbons. In the presence of oxygen, carbon monoxide, carbon dioxide and water are

included among the common combustion products. The main toxic products from PVC fires are hydrogen chloride (a

sensory and pulmonary irritant) and carbon monoxide (an asphyxiant). Toxicity of the Pyrolysis and Combustion Products of Poly (Vinyl Chlorides): A Literature Assessment, Clayton Huggett and Barbara C. Levin

Burning PVC (especially produced by electrical arc) also generates phosgene poison gas (see WW I) in some quantities

Editor's note: The post above is a quote from a work first written by C.Higgins, in 1987

[JPMacG]

Thank you all. That is very helpful.

By the way, I had ABS and PVC transposed in my first post.

It certainly makes sense to me that both should be permitted, and it seemed unduly restrictive to me that they would insist on one exclusively.

The township in question is Northampton.

[rjbrown2]

I cited Huggett and Levin above. I am assuming if they are not primary and are quoting Mr/Ms Higgins in their work that they also cite him/her though it wasn't obvious when I read it. Is this a courtesy on your part or is it a CYA to keep the lawyers away?

[Bill Kibbel]

I cited Huggett and Levin above. I am assuming if they are not primary and are quoting Mr/Ms Higgins in their work that they also cite him/her though it wasn't obvious when I read it. Is this a courtesy on your part or is it a CYA to keep the lawyers away?

The editors are probably going to be a little sensitive about posts containing content from other sources. Google is now aggressively penalizing web sites under the US Digital Millennium Copyright Act. Even if the information from another source is posted without any intent other than to be helpful, sites are regularly being removed from Google's search results.