Question of ABS Versus PVC DWV Use

[hd54kh]

Hey all, I need to do some drain and vent work in a bathroom. I have a supply of PVC drain pipes that I would like to use. The existing DWV system in there is ABS. Just for general info what is the difference or advantage of one over the other? I know there is the glue that can be used on either but is there an issue if my new work PVC is added to the existing ABS?

I am using 3" stack/drain and 1- 1/2 vent for a toilet and vanity relocation.

Thanks in advance

Sawyer

 

[yatg]

is there an issue if my new work PVC is added to the existing ABS?

from the poop's point of view, pipe is pipe

 

[nadogail]

I happen to prefer ABS over the light weight PVC sold for DIY projects. The ABS seems more sturdy than the white stuff.

 

[csp]

I happen to prefer ABS over the light weight PVC sold for DIY projects. The ABS seems more sturdy than the white stuff.

I can't find anything other than schedule 40 unless I go to a plumbing supply house. The big box stores around me certainly don't have the thin walled DWV PVC. I wish they did.

 

[hd54kh]

Thanks all for getting back to me, my last big box trip there wasn't much ABS on the shelf but lots of PVC. I do have a good bunch of PVC fitting from my last home which would be nice to use up.

My thought is there any issue with the flow of solids from the transition of one material to the other or do both equally keep a smooth bore?

Sawyer

 

[LOW1]

I think it has more to do with local tradition than anything else. Go to northern Minnesota for example and the Menards will have ABS. In Iowa it’s PVC. I would not hesitate to use what you have. Use a fernco type coupling to join the two types if you want. Point it downhill and gravity will do it’s thing.

 

[rburke65]

Yes most time us DIY selfers need a degree in plumbing to figure all this out.

 

[Innovate1]

I don't think I have ever seen ABS in the Missouri/southern Illinois area. If I did it was rare. When I was in Oregon many years ago I saw both. Interesting that Menards up north carries ABS. I thought it might be a regional code thing...

 

[speed bump]

I think it has more to do with local tradition than anything else. Go to northern Minnesota for example and the Menards will have ABS. In Iowa it’s PVC. I would not hesitate to use what you have. Use a fernco type coupling to join the two types if you want. Point it downhill and gravity will do it’s thing.

Supposedly ABS handles cold temperatures better which may be why its more popular in Minnesota.

Personally I grew up using PVC and its common where I am so unless someone tells me to use ABS I use PVC.

 

[FredWanaker]

so I have been reading these threads and thinking about our ABS pipe that broke inside the kitchen wall last year and what I went thru to fix it. What happens to ABS when several gallons of boiling hot water are often poured down the sink, or the dishwasher kicks out loads of that super heated water? What does PVC do? I've used hot water to soften PVC to bend it.

 

[billconner]

I don't have a preference but lived in one jurisdiction - 30 years ago - that speciffically did not allow mixing them in same house - all one or the other. Times, and codes, change, but be sure.

 

[Innovate1]

so I have been reading these threads and thinking about our ABS pipe that broke inside the kitchen wall last year and what I went thru to fix it. What happens to ABS when several gallons of boiling hot water are often poured down the sink, or the dishwasher kicks out loads of that super heated water? What does PVC do? I've used hot water to soften PVC to bend it.

I doubt much movement would happen from a dump of hot water through PVC. Yes, it does soften. I rigged up a steam pipe when I needed some long sweeps in PVC conduit. The piece to be bent went inside so it got heat inside and out. It didn't get to the point of colapsing but was easy to bend. With heat only on the inside I would think it would be much less flexible as plastic isn't a great conductor of heat and the outside surface will be cooler. The pipe I used for the outside steam container was also pvc and it did droop a bit in the middle.

 

[sixty4]

I worked with cast iron copper abs and pvc as I grew up going through the trade. I will stick with pvc for a residental home.

 

[jkuro]

Bottom line Abs is the cheapest that's why it is used more often. Just like roof trusses cheapest way to go. PVC is thicker walled and is a little quiete.

 

[finn]

I used pvc, because it has the best availability here. Menards has some abs, but not much.

Had a rehab done by a contractor. He preferred abs because over the years the solvents used with pvc frequently caused him health issues, particularly when working in tight crawl spaces. Abs solvents didn’t affect him. Apparently they’ve less volatile.

 

[hd54kh]

This is my first round with ABS. My last home everything was PVC and is why I have a small lot of fittings. I moved them here and would like to use them up. I'm going to push a few together and see how the IDs line up. If it stays as a smooth bore I' mixing them up using the correct glue.

As far as hot water, we usually run the cold water as we pour down the drain to chill it down so never have worried about softening the pipes.

Terry

 

[yatg]

Don't worry about it. The poop rides the wave.

 

[deminimis]

I vote for PVC. Previous house pool plumbing and UG sprinklers were all ABS. I had to replace all of it due to failure (approx 20 years ago). PVC still going strong.

 

[MongoTA]

Might be smart to check with your AHJ. Some towns specify one pipe and prohibit the other. Other towns allow either.

I can't say if this is true or not, but a common belief is that PVC can muffle the sound of water a bit better than ABS, so that can be good for DWV, especially for muffling toilet waste.

PVC needs a primer and when the primer is dry, then glue. ABS just needs to be glued.

Mixing the two? Using ABS-PVC solvent glue is not a code-approved option for in-house residential construction. Use a coupling hub, which a previous posted recommended. To meet code the coupling should be UPC approved, meaning it will have the UPC trademark on it. The trademark looks like a small shield (think shield as in 'sword and shield' like in the movie Braveheart) with 'UPC' on the face of the shield. The better couplings have stainless steel ring clamps on each end, with stainless straps running the length of the coupling to provide rigidity across the joint when it is made up.

Will ABS-PVC glue work? Will a non-UPC approved coupling work? Yes. But you might get dinged in an inspection when selling the place. Or if you do some sort of permitted work down the road and when inspecting that the inspector happens to see an ABS-PVC hybrid system, the inspector might look at everything with a more critical eye.

Good luck!

 

[hd54kh]

Might be smart to check with your AHJ. Some towns specify one pipe and prohibit the other. Other towns allow either.

I can't say if this is true or not, but a common belief is that PVC can muffle the sound of water a bit better than ABS, so that can be good for DWV, especially for muffling toilet waste.

PVC needs a primer and when the primer is dry, then glue. ABS just needs to be glued.

Mixing the two? Using ABS-PVC solvent glue is not a code-approved option for in-house residential construction. Use a coupling hub, which a previous posted recommended. To meet code the coupling should be UPC approved, meaning it will have the UPC trademark on it. The trademark looks like a small shield (think shield as in 'sword and shield' like in the movie Braveheart) with 'UPC' on the face of the shield. The better couplings have stainless steel ring clamps on each end, with stainless straps running the length of the coupling to provide rigidity across the joint when it is made up.

Will ABS-PVC glue work? Will a non-UPC approved coupling work? Yes. But you might get dinged in an inspection when selling the place. Or if you do some sort of permitted work down the road and when inspecting that the inspector happens to see an ABS-PVC hybrid system, the inspector might look at everything with a more critical eye.

Good luck!

Thank you for this bit of direction. I agree the flowing product doesn't mind what water slide to ride. It is also correct that whatever I do should be able to pass visual inspection in the future. I recently sold my house of 40 years and when a buyer is close t the deal is not the time to panic repair any flaws.

Maybe I'll check into going all ABS and sell the PVC pile I have. Do it once and be done.

Sawyer

 

[TailGunner3000]

My experience is ABS will fail long before PVC. About 15 years or so.