What about this method to join PVC and ABS?

[Sluggo]

I'm putting in a shower P trap that will be buried under a concrete slab. The lines and P trap are ABS, but the shower drain base I want to use is PVC. Based on advice from this forum, I'm avoiding using transition cement and will likely use a banded coupling to connect them. However, one other thought occurred to me and I'm curious what forum members think of this: Use PVC cement to weld a 2" threaded, male PVC coupling to the shower base; use ABS cement to weld a 2" threaded female ABS fitting to the ABS P trap; wrap the threads with teflon tape and screw the PVC and ABS fittings together. Any reactions?

 

[Terry]

Today I used an Oatey shower drain on a Kohler Cast Iron shower pan. I was able to drop the pan down on a 2" riser from the P-Trap, and then tighten it in place from the top.

Edited, removed a comment.

 

[Sponsor]

 

[Sluggo]

Right now I have a 14" X 18" hole in the slab that gives me complete access to the P trap I'm installing. I could assemble the shower base, the threaded fittings, and the P trap, then insert the whole assembly into the hole and glue the end of the ABS P trap to the existing ABS drain line. When everything was set, then I'd backfill the hole with concrete and make it level with he rest of the slab. So, for my particular situation, It looks like it would be easy to put together. Just curious about the pros and cons -- if any -- to using the threaded fittings to make the transition.

 

[Terry]

The treaded would work. They take a little more space than banded, but not much.