Replies

1. 
   McPlumb | Jun 09, 2007 01:06am | #1

   I've used both ABS and PVC and I can't honestly say one is better than the other.

   On room additions and remodels if there is already one type of plastic there, that is what I go with.

   I do know that in some areas its harder to find ABS.

   Our local code allows three toilets on a 3" line.

   The difference between 3"and 4" fittings cost wise is noticeable.

   There is some theory that low flow toilets should be on 3", but if there is enough slope in the 4" you won't ever notice the difference. The larger the pipe the less slope is needed, is kinda a general rule of thumb. So a 4" with a bit extra slope will work the same.

   The code intention is to move the water fast enough to cause a scouring effect.

1. 
   Matt | Jun 09, 2007 04:49pm | #5

   >> larger the pipe the less slope is needed, is kinda a general rule of thumb. So a 4" with a bit extra slope will work the same.  <<

    

   I'm confused.... (what else is new)  maybe it was a type-O?

1. 
   McPlumb | Jun 10, 2007 02:58am | #11

   Traditionaly it was 4" and a 3.5 gal. flush, today it's 3" and 1.6 gal. flush. If you are going to put a low flow toilet on a 4"pipe in a new installation you can add a little more slope to get the scouring affect.

   Hope that clears it up a bit.

2. 
   davidmeiland | Jun 09, 2007 06:47am | #2

   Chemically speaking, PVC is a horrible material. When burned it releases dioxin. Apparently there are even movements afoot to ban the use of PVC in some places. I don't know if ABS is any better, but it's what we use here and as far as I'm concerned it's just fine.

1. 
   fingersandtoes | Jun 09, 2007 07:47am | #3

   Exactly. Our code won't let us use PVC inside the foundation. We only use it for drain fields and perimeter drains.

   I have seen articles on using it for bathroom ducting (in FHB?). Another no go here.

2. 
   Matt | Jun 09, 2007 04:56pm | #7

   Interesting... So, are you saying ABS doesn't give off poisionus gas when burned?  I have no idea - I'm just trying to learn something here.  Didn't we used to have a firemen around here?

    

   Edited 6/9/2007 9:57 am ET by Matt

1. 
   davidmeiland | Jun 09, 2007 05:06pm | #8

   Duuno about ABS, but do know that PVC is nasty throughout all phases of its lifetime, especially production and disposal.

1. 
   goldfreaz | Jun 09, 2007 06:47pm | #9

   ABS has air voids, so it is lighter.  Toxic fumes would be proportional to weight with everything else equivalent.

1. 
   Matt | Jun 09, 2007 10:14pm | #10

   There is cellular PVC and solid PVC.

3. 
   MikeMicalizzi | Jun 09, 2007 10:33am | #4

   The only other difference I've noticed between ABS and PVC (aside from availability) is that, when joining the pipes together, you don't have to use primer on ABS like you do on PVC, so that saves a little time on the installation.

4. 
   Matt | Jun 09, 2007 04:53pm | #6

   We don't see ABS here.  I wonder what the material price difference is?  Regarding the 3" and 4" waste pipes, do an advanced search here at BT.  (middle upper left of screen)  We just had a somewhat lengthy discussion about that about 2 or 3 weeks ago.