Drain to floor

As can be seen in the pic above and the title, I'm stuck on how to connect this last piece of drain pipe to the floor drain. I have a sch. 40 socket Wye which has not been cemented yet to the floor drain pipe. Everything else you see has been primed/cemented, except the Y screen filter, which had male threaded ends. The local inspector said anything less than 4" did not require purple primer, and although he recommends it generally, he said he wouldn't care if I used one-step clear cement (contains both primer and cement.) The Y-screen was a last-second addition that I thought may be beneficial to make sure the corrugated french drain it goes into didn't get debris potentially inside of it. I'm not entirely sure it is necessary, but after the effort I expended putting in a french drain properly, I didn't want to risk it clogging internally from random debris somehow.

I had originally dry-fitted all of this and had it all connected great from source to the drain. As I'm sure is apparent, I'm not a plumber and didn't realize how much "shrinkage" I would have after the pipes were primed and cemented, which caused my great alignment and connections to be slightly off. From some tests I've run, it seems like my dry-fitting only gets the pipes seated about 3/4", with the fully primed/cemented seated pipe going in about 1 3/8". Now that it has all been cemented up to this point, and this last angle slightly changed, I don't have the "give" (in the hole in the wall that the pipe goes through) to raise the pipe enough to seat a cemented pipe in the 45 degree fitting, and then push it back downwards into the Wye. It also seems like it might create a slight upward slope (on the other side of the wall) if I cut out a little from the top of the hole in the wall on both sides in order to lift the pipe higher.

Is the only real answer to cut more material from the hole in the wall on both sides, so that the pipe can be raised a little, in order to be able to fit a cemented pipe in both ends? Or is there some trick of the trade on how to do this that my n00b ass just simply doesn't know?

The floor drain was originally intended to be for a "mud sink", but has now be repurposed to handle output from a sump pump. The slope seen in the pic is not the slope throughout the rest of the drain; the rest is approximately 1/4" per foot. Even though it will be under pressure via the sump pump, I sloped it anyways just to be redundant. This last 4' or so of pipe got extra sloped when I cemented the fitting right before what you see at a slightly steeper angle than I had when I dry-fitted it, resulting in this steep drop.

4 Answers 4


Why not simply remove that hold bracket on that wall that holds the pipe? That should provide enough give to get you off the bind. Maybe not, I can't see the left side on the picture.

Another trick is to simply use basic pvc coupler. Grind off the middle stop that is inside of it.

Mark both pipes that feeds into the coupler so you know how far the coupler goes over each pipe. Heat the coupler a little so it expands. Feed it over the pipes in and out so you know it slides in and out and everything is cooporating.

Just any propane torch or even an oven will do, or boiling water. It just relaxes the pvc is all. [With propane heat you can turn a regular PVC pipe in to a coupler believe it or not, no problem]

Use a little extra glue and feed it over one of the pipes , then the other pipe. As the couple cools off it will shrink back perfectly. It won't take much heat for the coupler to be forgiving.

You can also get one of these compression fittings since it is just a drain and is not a pressure pipe. Even with pressurized fresh water these things work but they recommond if it is buried for some reason. This maybe your fastest simplest option.
So you have many options.

Hope this helps. Let me know if any of this worked for you.

Take good care.

compression coupler

  • Hey, thanks for the reply! I previously tried removing the clamp to raise the line, but it still was not enough because the hole in the wall the pipe goes through about 2' to the left of the pic did not have enough room to lift it further. I'm not positive I understand how the heating will work, but I'm going to try it today (and the other suggestions if necessary) and will report back. Oct 30, 2022 at 15:05
  • 3
    You can buy a repair coupler and not have to bother grinding. You do have to be very careful about timing, though.
    – Ecnerwal
    Oct 30, 2022 at 15:35
  • @ShunsukeSengoku, how to heat the coupler, edited in the video. Gently with a propane torch, oven, or boiling water. It won't take much. With propane torch you can turn a pipe into a coupler. :-) Oct 30, 2022 at 19:31

You need a union fitting, which can be glued to each part with appropriate pipe stub, then screwed together (not pipe threads - unions are different, so they can do what they do.)

  • An alternative is a rubber fitting, or a PVC repair coupling. I tend to think from experience that the repair coupling might well get stuck in the wrong position while I'm trying to get it all together, so when needed I use rubber ones. Next time plan ahead so you assemble thngs in a direction that always allows you room to work.
    – Ecnerwal
    Oct 30, 2022 at 0:47
  • Are you sure those rubber fittings are legal above ground? diy.stackexchange.com/q/119494/36011 Oct 30, 2022 at 16:01
  • A shielded (reinforced) rubber coupling is still a rubber coupling.
    – Ecnerwal
    Oct 30, 2022 at 16:24

Change the order of assembly. If the connection between the male adapter and the upper 45 degree elbow is made last, you'll be able to get just enough flex in the pipes on both sides to be able to lift them up and force the joint together.


Available is a rubber coupling, with two stainless steel worm drive clips. Its i.d. is slightly more than the o.d. of the plastic pipe it'll fit. Cut the tube that goes between the two unions, leaving enough 'slack' to slide this rubber coupling over, then back over the other, cut part. Best to mark where it needs to slide to before. Tighten up the clamps, and, viola. There's also going to be enough wiggle room to take into account slight misalignment of the two 'sockets', and the propensity to easily disconnect the whole lot later, which you won't do with cemented joints.

  • Are you sure rubber fittings are legal for above ground use? diy.stackexchange.com/q/119494/36011 Oct 30, 2022 at 16:02
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    @statueuphemism - here we go again! I keep banging on about location in questions. I'd imagine they're more legal above than below ground, but LOCAL byelaws will vary. And in non-pressurised situations, I can't really foresee problems anyway.
    – Tim
    Oct 30, 2022 at 16:20
  • I am, in fact, sure of that, for my location. The odd thing is that the shielded (reinforced) ones are not legal below ground, but the unreinforced ones are.
    – Ecnerwal
    Oct 30, 2022 at 16:22
  • @Ecnerwal - exactly. There's no point in answering for what's relevant in your (or my) location, as that may have little or no relevance to the OP and theirs.
    – Tim
    Oct 30, 2022 at 16:44
  • @Tim IRC in the linked question is “International Residential Code” that a lot of residential codes are based on. The other major player I am aware of is the Universal Plumbing Code (UPC). I am sure there others outside of the United States as well, but the IRC is a major standard that applies verbatim (and with local exceptions) to a lot of places which is why I made my comment. Oct 31, 2022 at 0:58

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