I know the type of cement that can be used to join ABS and PVC is often frowned upon by codes. What is the problem? For example, does it result in leaks or is the joint structurally weak?

Hi Dennis...

When pvc is joined to pvc and abs to abs the joints are not glued as much as they become WELDED together using the correct primers/cements, of course. When different plastics are joined the process is not really a compatible weld anymore... but more like a glued joint.

The idea is that the two plastics are different plastics and expand and contract at different rates which increase the chance that the fitting and pipe could create cracks/leaks.

They have transition fittings that work so much better anyway... such as shielded clamps (plastic to plastic) or by joining an abs male adapter to abs pipe and a pvc female adapter to pvc pipe and then screwing the connections together (using thread sealant)... just a couple examples.

Let me know if you have more questions...

MARK

Thanks, that's just what I wanted to know.