ABS

[rlskfoster]

Can someone give me the does and don'ts of ABS in homes. I know it is a black plastic but I am unsure if it is all bad or just in some uses.

Thanks.

Buster

[Jim Katen]

Originally posted by rlskfoster

Can someone give me the does and don'ts of ABS in homes. I know it is a black plastic but I am unsure if it is all bad or just in some uses.

Thanks.

Buster

There was some bad ABS many years ago, mostly in California, but that's history.

You can use it for drain, waste & vent piping.

Don't connect it to PVC with adhesive.

Otherwise, you'd follow the same rules as you would with PVC DWV.

- Jim Katen, Oregon

[rlskfoster]

I did a mobile the other day and it had a mix of ABS and pvc under the sinks. None was used for supply only DWV. I

I didn't write anything on it but I kept having that nagging question in the back of my head.

What is used for connections? Now I can't remember if I saw any purple pipe cleaner and PVC glue or not. I had some pictures but you can't tell from them either.

Buster

[Jim Katen]

Originally posted by rlskfoster

I did a mobile the other day and it had a mix of ABS and pvc under the sinks. None was used for supply only DWV. I

I didn't write anything on it but I kept having that nagging question in the back of my head.

What is used for connections? Now I can't remember if I saw any purple pipe cleaner and PVC glue or not. I had some pictures but you can't tell from them either.

Buster

You probably saw slip joints between the PVC trap arm and the ABS sanitary tee.

- Jim Katen, Oregon

[RobC]

Originally posted by rlskfoster

Can someone give me the does and don'ts of ABS in homes. I know it is a black plastic but I am unsure if it is all bad or just in some uses.

Thanks.

Buster

With the exception of some old PVC and really old copper and cast iron, ABS (residential) is used here exclusively without any major issues.

BUT multi residential is another story. The material is NOT allowed to penetrate through a fire seperation wall as it can create its own fuel to burn. PVC is the preferred material for penetrations.

Here is my number don't with ABS

DONT use the stuff to drain second floor bathroom, laundry, etc. Water draining in ABS is noisy that insulation will not cure. I recommend cast iron be used between living spaces to minimize noise.

ABS can be combined with PVC with transition cement, mainly used in renovation and seldom if never in new construction.

[Jim Katen]

. . . DONT use the stuff to drain second floor bathroom, laundry, etc. Water draining in ABS is noisy that insulation will not cure. I recommend cast iron be used between living spaces to minimize noise.

Good point. ABS sounds horrible, especially when there's a bathroom over a dining room.

ABS can be combined with PVC with transition cement, mainly used in renovation and seldom if never in new construction.

That's a very common misconception, even among plumbers. Transition cement has a very limited application. It's supposed to be used to join one drainage system to another drainage system, not to join parts within a single system. If you see an ABS to PVC cement transition during the course of a normal home inspection, chances are it's incorrect.

Transition cement complies with ASTM D3138-04 which reads, in part:

1.2 These cements are intended for use in cementing transition joints between ABS and PVC materials in non-pressure applications only (25 psi (170 kPa) or less).

Note 1: This specification was developed to provide a means for joining an ABS non-pressure piping system using a solvent-cemented transition joint, for example, joining ABS building drain to a PVC sewer system. The intention was not to create a specification for an all purpose ABS-PVC solvent cement that would be used for mixing of ABS and PVC piping materials nor to specify a cement that could generally be used for either material. Specific cements for ABS or PVC components should be used.

- Jim Katen, Oregon

[RobC]

I seldom find transition fittings and/or a mixture of different material in one system as the costs can be probihitive. The cement is costly and not a common item found with contractors.

I've personally had to add PEX lines to PB with a 'transition fitting' and transitioned ABS drain lines to PVC as PVC is not readily available in my market.

I have to agree that multiple changes of material within the same run or system would imply an amateur installation and one to be cautious of.

Quote:

"If you see an ABS to PVC cement transition during the course of a normal home inspection, chances are it's incorrect. "

I'm not sure that it would be incorrect as such unless the overall installation was incorrect itself, but as for the joining of the two systems, it's my experience that the joint is as strong as the rest of the joints.