Need advice before pouring concrete

[joco]

Hi, I'm finishing my plumbing project and before pouring concrete I wanted to ask for some advice. My shower riser is not plumb as you can see from the pictures, so I was wondering how forgiving are the shower drains? Does my shower riser needs to be perfectly plumb or it will work like this? I'm planning to make a box around the shower drain pipe so there will be access if small adjustments are needed when building the shower bed. Thank you very much in advance.

[jadnashua]

It depends on the drain you use, but generally, things don't go particularly well if the riser is not plumb, especially if it is a large diameter drain like used on a bonded membrane shower (Kerdi, Hudroban, etc.). While kind of a pain to fix, it is only possible now before you fill it in with concrete.

[Carbidetooth]

What Jim said. I might add that while the bulls eye level seems to agree with the level on the pipe in this case, there's many ways that it might not, such as a non-square cut on pipe. Use the rubber band and check at 90° intervals.

Do yourself a favor and fix it now. Might be as easy as gluing a coupling in the riser and coaxing it a little beyond plumb (it will probably spring back a bit) until glue dries. While not advertised as such, there is wiggle room in fittings.

See if you can push on riser enough to get it plumb so you can eyeball how much it needs to move.

[joco]

Thank you Jim and Peter. I'm still thinking between regular tile shower or Kerdi kit one. I tried to keep it plumb while joining the pipe but I was not successful. The pipe should be square because I used miter saw to cut it but you never know Do you guys know what kind of coupling should I use for that small angle adjustment? Has anybody used the one shown in the picture? I'm not sure that I can adjust the angle if I use regular PVC coupling since those seem to be tapered without any wiggle room.

[jerrymlr1]

You could take a heat gun and bend it to where you need it.

[Carbidetooth]

I wouldn't use a flexible coupling unless there was no other way. It really helps in the end game if it's both plumb and rigid.

To prove there is wiggle room in PVC, take a couple of pieces and a coupling and try it. Add to that the PVC glue essentially melts the surface layer so that adds a little, too.

Although I've never measured it, I suspect I could gain at least 2° or 3°. I've also been known to heat PVC and bend it, but it takes a deft touch with a torch. I've never tried it with a heat gun.

[joco]

Peter,
I just did that a couple of minutes ago and you are right

I'll cut the riser and use a coupling and see if I can fix it by myself. Should I hold the pipe plumb as long as possible or make some fixture/re-bar and tie it to it while the cement cures?

Thank you again

[Carbidetooth]

Simple fixture might help...set up prior. Gotta be quick though, not the time for lollygagging.

[jadnashua]

PVC cement melts the plastic...there's a little bit of flexibility especially if you use a bit of excess cement to melt a bit more plastic than 'normal', and then hold things where you want them until the solvent evaporates to then hold things in place. But, something like a couple of 1/8 or 1/16 bends, stacked with a short connecting pipe gives lots more flexibility. Certainly depends on how tall the riser is, but with a couple of small angle bends, you can correct any error if you have room.

[Davy]

For just a little adjustment, I wedge a rock against the concrete and pipe to hold it where I want it.

[joco]

I just wanted to thank you all for the great tips. The riser pipe looks much better now. Should I make box around the pipe or 4in coupler will work too?

[jadnashua]

What kind of drain are you using? You need at least enough room around the pipe for a coupler to be cemented onto it when setting the drain. Then, some drains have a much bigger funnel than others, and whatever is beneath cannot impact that so your drain height can be what you want it to be.

[joco]

Jim,
I'm not sure yet about the drain, since I'm only doing the rough plumbing for a future bathroom. It will end up being Kerdi most likely since that looks easier for a beginner. I'll leave a box around the drain, so I don't brake concrete in the future. Thanks