Is it illegal or bad practice to join 2 drain pipes.........

[Pmaru77]

I have 1 1/2" abs drain coming off a shower/bath. The drain is ABS and glued where there is no slip fit or compression fittings. I'm concerned that it may be too rigid and a good earthquake may cause a crack or failure. I was thinking of putting in a rubber 1 1/2" coupling on the horizontal pipe that leads to the downspout. This is on the second floor of my house. The drain already had a failure a few years ago where the vertical drain sheared in half but luckily inside the furnace closet so I was able to gat a coupling on it(abs glued) so there is some wiggle or slack in the drain tube array that allowed me to get that coupling on. Maybe that implies that there is enuf slack in the system already and I'm ok that it's not that rigid.

Is it ok to put a rubber coupling in the horizontal position? As far as support, if I cut the pipe and install, there is plenty of support for both sides of the drain.

 

[Gary Swart]

Not legal. The fitting you refer to is legal only when used underground because the soil will prevent the joint from shifting.

 

[Sponsor]

 

[Terry]

A rubber coupling without the metal wrap on it will sag over time, badly.

They do make shielded coupling that hold the pipes in-line.

 

[Pmaru77]

Not legal. The fitting you refer to is legal only when used underground because the soil will prevent the joint from shifting.

I got lucky and forgot to glue the final ABS connection. When I realigned the piping, all was good so I glued her in place and I'm done. Thnx.
No coupling added.