Mixing ABS and PVC Drain Fittings

ABS is not a typical material used in our area and it is my understanding these two different materials cannot be reliably solvent welded. Is this true? Obviously, we cannot determine what chemical was used as it is not visible. What do others do when you run across a situation like this?

There are glues that can glue the two together. It’s green in color.

Greg… Pic one… is that a sink with a cleanout below? That’s looks to be an awefully long drop. Did you measure it?

To your original question… dissimiliar plastics make it into my report for repair.

Hi Jeff,
Pic 1 shows a wye for a laundry tub located opposite the wall. Looks like a home-owner install. This drain was a wall-mount box for a washing machine again opposite the wall.

I was concerned that both bathrooms and the kitchen used a horizontal ABS nipple into the PVC trap and it looks original. The solvent was clear and no evidence of any primer. The home was built in 1996.

Generally, only one transition fitting is permitted between old and new work with the appropriate transition solvent. Check with your local AHJ





Previous post on the subject.

Only the green is allowed in WI

You know, the message board really stinks for searching. I always try a search to find a post before creating a new one and nothing showed up searching for ABS PVC. I hope with the IT staff moving to CO this can get fixed! Thanks for the heads up.

It’s easier to use Google to search the MB than the built in search function.

Sad but true. :wink:

There are glues that can glue the two together. It’s green in color.

flexible bellows

2009 IRC P3003.2 Prohibited joints.
Running threads and bands shall not be used in the
drainage system. Drainage and vent piping
shall not be drilled, tapped, burned or welded.
The following types of joints and connections shall be prohibited: 1. Cement or concrete.
2. Mastic or hot-pour bituminous joints.
3. Joints made with fittings not approved for the specific
4. Joints between different diameter pipes made with
elastomeric rolling O-rings.
5. Solvent-cement joints between different types of plastic pipe.
6. Saddle-type fittings.
* Code Commentary: *Running threads are threads that
have no taper and,therefore, will not make up tight
to produce leak-free joints.
Drilling, tapping, burning and welding to create fittings
for connections are prohibited because these
means do not create the smooth transitions afforded
by directional fittings and can damage the pipe.
This section provides requirements for joints between
pipe and fittings of different materials. Cement
and concrete are not effective in sealing a pipe joint
because such materials are inflexible and susceptible
to cracking and displacement. A rolling O-ring has no
resistance to being pushed or rolled out of a joint when
exposed to pressure or the movement of pipe caused
by expansion and contraction. A solvent-cement joint
is a homogeneous chemical bond made between a
pipe and fitting. The bond is accomplished because
the chemical composition of the joint surfaces is the
same. If the materials are different, the joint may not
form a proper chemical bond, and the strength and integrity
of the joint will be adversely affected. For example,
solvent cementing is prohibited between ABS and
PVC, PVC and chlorinate polyvinyl chloride (CPVC) or
ABS and CPVC. Saddle-type fittings may be moved
out of alignment, can weaken the pipe because of the
pipe wall penetration and typically do not form a drainage
pattern connection. However, saddle-type fittings
are commonly used for connecting

Does PVC require a primer? Does ABS require a primer? What happens when a primer is applied to ABS?

You are correct about that though I still often try.

In WI, you are permitted to have a transition fitting between old and new work as long as the green colored ABS PVC compatible solvent is used.

That does not mean you can mis and match ABS and PVC at random within the system.

Generally you are allowed a single transition fitting.

Michael, please reply to post 13.

They make clear primer. It isnt all purple and orange. Home Depot sells it.

Primer is only required for PVC so yes it would need to be primed.

However primer is not required on ABS and is optional.

I have used clear primer many times on ABS with no negative results.

More info here

IRC code commentary:

“Because each type of solvent cement is specifically
designed for a given piping material, all-purpose solvent
cement or universal solvent cement cannot be used to
join ABS pipe or fittings unless it conforms to ASTM D
. Solvent cement for each plastic pipe material requires
a unique mixture or combination of solvents and
dissolved plastic resins to conform to the standard. Although
all-purpose cement may dissolve the surfaces of
ABS, PVC and CPVC, it may be too aggressive or not
aggressive enough to keep a joint strong enough to meet
the minimum joint strength requirements of the referenced
standard. Solvent cement must be identified on
the can as complying with ASTM D 2235.”

Joe, WI has their own plumbing code.

The use of Green transition cement may not apply in your jurisdiction.