Does this P trap look ok?

[Sluggo]

Below is a picture of the P trap I'm installing for my new shower. It's in a hole in my slab, and currently dry-fitted together. Before I glue up the ABS and re-concrete the slab I want to make sure the configuration is ok. The vent is in the upper left and comes up through the slab just behind the blue foam. Feedback, please?

 

[Dj2]

If you chip away some more concrete around the 45, then cut the 45 out - you will have a straight shot from that point to your drain point. No 90 and no 45.

 

[Sponsor]

 

[Tom Sawyer]

I'd rather not see the elbow but it should be ok.

 

[hj]

The 45 is "fitting to fitting" with the tee, so if he cuts it off he will have a different problem. Cutting close to the 45 and installing a second 45 would be a better drain.

 

[Sluggo]

Thanks for all the thoughts. I can't chip away more concrete to get the 45 out...radiant heat hose in the slab right there.

I like your idea, hj, about cutting close to the 45 and putting in another 45. I'll see if I have room to do that and still position the vertical pipe where my drain needs to be.

 

[Terry]

Like hj, remove the medium 90 and use a 45 there.

 

[Sluggo]

Ok, I did cut the pipe back and got an improved setup. I couldn't straighten it out any more than this because of needing the drain pipe to come up at a very specific point to accommodate a linear drain. However, I'm happier with how this looks. Thanks for urging me to get rid of the 90.

 

[Terry]

Your hand snake will love you for this.

 

[Sluggo]

Yes, it is much improved!

Two last questions. I can now glue the shower drain assembly to the vertical stub and concrete it, but I was also thinking about allowing for any settling that might stress the P trap configuration, as I am slab on grade.

First, I was planning to wrap the vertical pipe coming up from the P trap to the pipe coming down from the drain assembly with a layer or two of 1/8" flexible foam sheeting (sill wrap?) so that the concrete wasn't right up against the ABS. I assume that is recommended practice...or code?

Second, instead of solvent welding the vertical pipe to the shower drain assembly, would there be any benefit in simply connecting the two vertical pieces with a banded or no hub coupling? Would that allow a little movement to occur if the piping in the sand/soil dropped in relation to the drain assembly encased in 4" of concrete slab? Or do those couplings resist any movement once they are tightened? Or am I over-engineering this?

 

[NHmaster3015]

You want a Souix Chief 892-S2

◾PVC drain body with outer locknut
◾Elastomer push-joint gasket installs over 2" Sch. 40 pipe
◾430 stainless steel strainer
◾Do not use putty with plastic shower drains

 

[Sluggo]

nhmaster-
Thanks for the input. However, I neglected to mention that I am installing a linear drain with a mud bed and membrane so I need to use one of those shower drain assemblies that traps the membrane. Given that that is what I have to use, do you (or anyone else) have any thoughts on whether I should try to have a flexible connection between the drain assembly and the P trap piping?