How to Fix a Leaky Shower Drain – Part 8

How to fix a leaky shower drain with a lock nut against the bottom of the shower pan. This series is continued from Part 7.

Reader Question: Leaky Shower Drain

I received this question from a reader with a leaky shower drain in loft shower:

Hello Bob,

I live in a loft with concrete floors and it has a small shower stall up on wood. My shower starting leaking about a week ago and at first I thought it was the caulk around the shower so I replaced it but it still leaked. So I took off the step in front of my shower to get underneath and ran water and found the leak coming from the drain body. So after finding this wonderful site, I tried to repair it but I am having trouble getting the strainer body to release. I’ve tried channel locks and a long screw driver but still no luck. I was wondering if you have any other tricks or tips.

Also mine does look slightly different from the one pictured, it has two square pegs cutout and those are what I’ve been trying to use for leverage.


T. Sparks

I asked Mr. Sparks to send photos of the shower drain to better understand the situation. Mr. Sparks replied:

I’m currently working 4 part time jobs and going to school so I’ve been quite busy lately.  Anyhow here are the photos of the shower drain. I just unscrewed the locking nut and it still won’t budge and it really looks as though it’s been glued in with the purple plumbers glue. If this is the case is there anyway of taking this out without cutting the pipe?

Leaking Loft Shower Drain

Here’s the shower pan and strainer body photos provided by Mr. Sparks. The drain is stamped with the manufacturer’s information E.L.M. CLEVE OHIO PVC DWV 2″ 42-304. I searched the Internet but was unable to find the manufacturer or drain model.

E.L.M. Cleveland Ohio PVC Shower Drain Model #42-304

The strainer body screws into the drain and has two notches to accept a shower drain wrench like the BULLDOG shower drain wrench.

View of the leaky shower drain and PVC plumbing on the elevated wood platform:

Loft Shower: Shower Pan Bottom and Leaking Shower Drain

Closeup of the leaking shower drain in this next photo. This shower drain is a “solvent weld” model meaning the drain body is glued to the 2 inch PVC drain pipe. A standard 3.5 inch PVC lock nut compresses the black rubber gasket against the bottom of the shower pan for a water tight seal. A reducing coupler is used to adapt the 2 inch PVC pipe from the drain to the 1.5 inch PVC pipe to the P-trap.

Leaking Loft Shower Drain Parts Diagram

Shower Drain and Lock Nut Assembly

It helps to understand how the shower drain fits together before talking about the repair steps.

The loft shower drain is a solvent weld model, however it is similar to the Sioux Chief Push-Joint/Solvent Weld Shower Module Drain #826-2PK shown below. The key items being the drain lock nut is tightened to compress the black rubber gasket against the bottom of the shower pan to make a water tight seal. (Note the 2PK model has a cylindrical black rubber compression gasket inside the drain body instead of a bare plastic as for a solvent weld drain, but let’s ignore this minor difference for now.)

Sioux Chief Push-Joint/Solvent Weld Shower Module Drain 826-2P

Below is shower drain as it installs on a 2 inch section of PVC drain pipe with the gaskets and lock nut arranged in the order of installation. For old work when repairing a shower drain, a large pair of Channellocks is needed to work the 3.5 inch lock nut.

Shower Drain Gaskets and Lock Nut Assembly with Channellocks

The adjustable jaws on the Channellocks will open to 3.5 inches to fit the shower drain lock nut:

Channellock Wrench on Shower Drain Lock Nut

E.L.M. PVC 2″ Shower Drain 42-304 Details

The E.L.M. model 42-304 shower drain looked like a hybrid compared to traditional drains because it appeared to have both a screw-in strainer body and a bottom lock nut. I asked Mr. Sparks to unscrew the 3.5 inch lock nut, drop the black rubber gasket down the pipe and push up on the U-bend to see if the drain would raise up above the shower pan. Here’s the photos provided by Mr. Sparks…

View of the loft shower drain after unscrewing the lock nut and dropping it down the pipe along with the rubber gasket. Notice the brown evaporation ring around the bottom of the shower pan drain hole where water has been leaking.

Leaky Shower Drain Repair: Lock Nut and Black Rubber Gasket

Mr. Sparks reported he was able to unscrew the lock nut by hand! The lock nut should be tight and require a wrench to loosen. A loose lock nut will not compress the black rubber gasket to make a watertight seal and will definitely cause a leak. My guess is the lock nut worked itself loose over time as the shower pan flexed slightly when a person steps in the shower.

Overall, the rubber gasket looks in good shape.

When Mr. Sparks pushed up on the U-bend, the shower drain body easily popped out of the shower pan drain hole recess revealing two interesting facts:

  1. The strainer body is threaded and therefore screws into the solvent weld shower drain body.
    This confirms the purpose of the two notches inside the strainer body – which are there to accept a drain wrench.
  2. A second black rubber gasket is used instead of silicone caulk or Plumber’s Putty to seal between rim of the strainer body and shower pan.

Shower Drain Repair: Screw-in Drain Body and Gasket

Leaky Shower Drain Repair Advice

My repair advice is:

  1. Get the Pasco 7099 Quick Set Drain Wrench.
  2. Unscrew the 3.5 inch lock nut from the bottom of the shower pan with Channellocks or a similar wrench.
    This will relieve the clamping pressure on the strainer body.
    Note: We already know the lock nut was loose (causing the leak) because Mr. Sparks was able to unscrew it by hand.
  3. Use the Pasco 7099 drain wrench to unscrew the strainer body – take care to hold the drain body so as not to torque the drain pipe and P-trap.
    If the Pasco wrench is too wide, grind down the ends to fit the notches in your drain.
    Idea: Since the strainer body will lift out of the shower pan recess, you might be able to unscrew it with a rubber grip cloth used to open jar lids instead of the drain wrench.
  4. Inspect the strainer and shower pan for cracks.
  5. Clean the dirt and crud from the strainer body, drain body and rubber gaskets as explained in the earlier installments of this series.
  6. Reassembly the drain by:
    – Screw strainer body in over the shower pan gasket.
    – Screw on the lock nut and tighten with a wrench to squeeze the bottom rubber gasket and clamp the strainer body down on the shower pan. Don’t over tighten the lock nut so as to avoid cracking the PVC plastic drain.
  7. Run the shower and check for leaks.
    Tighten the lock nut another 1/4 turn if a leak is noticed. Run the shower again and look for a leak. Recheck after a day or two to catch any very slow leaks.

Optional: Replace the Shower Drain Gaskets

Since the black rubber gaskets appear to be in good shape, this step is optional, but I would also replace the two rubber gaskets.

I verified with a new drain on my workbench the rubber drain gasket will stretch and can be slipped over the rim of the strainer body.

To replace the two rubber gaskets on this drain, do the following:

  1. Before reassembling the shower drain – meaning with the strainer body unscrewed and the top rubber gasket set aside – tie a piece of orange or yellow construction string (or kit string) to a new bottom shower drain gasket.
  2. Drop the end of the string through the gap between the shower pan drain hole and drain body as noted in the photo below.
  3. Pull on the string to start a section of the new gasket down the gap.
  4. Grasp the new gasket with your fingers and work around the shower drain body through the gap with the shower pan.
    Mumble cuss words as needed, but the gasket will eventually make it through the gap.
  5. When the new gasket is completely through and sitting on the old rubber gasket, cut off the old gasket with scissors.
  6. Reassemble the drain in the normal way.
    Remember, to also install a new gasket under the rim of the strainer body.

Shower Drain Repair: Gap between the Shower Pan and Drain Body

Good luck!

Bob Jackson

Copyright © 2016   Reproduction strictly prohibited.


22 Responses to How to Fix a Leaky Shower Drain – Part 8

  1. Arthur November 2, 2011 at 8:55 pm #

    Hello Bob,

    I have a similar problem to shower drain fix part 8, except the lock nut is RECESSED in the a very small circular cut out in the subfloor, I was able to remove the lock nut with two long srewdriver and replaced the whole drain assembly with sioux chef bronze model and the two rubber gaskets in shower pan and under the pan. I have tighten the lock nut, but still there is very slow drip leak.
    Is there a tip on how to tighten it more or may be something wron with the assembly? I could send pictures of the set up.


    • Bob Jackson November 3, 2011 at 7:56 am #

      The photos you provided via e-mail where very helpful in understanding your problem. Yeah – there’s no clearance to get a wrench on that 3.5 inch lock nut because the round cutout for the drain in the two layers of subfloor is only large enough for the drain. What happened is the contractor installed the drain on the shower pan before setting the shower stall in place.

      Leaky shower drain after cutting an access hole in the drywall ceiling:

      Closeup of the shower drain through the subfloor – no room for a wrench!

      From your e-mailed photos, it’s clear you have a “no caulk” shower drain – meaning the drain body fits over the PVC drain pipe and seals with an internal compression gasket and compression nut that screws in from the top of the dran. This is good news because it’s easy to replace the entire drain without sawing the PVC pipe.

      Here’s what you should do:
      1) Unscrew the 3.5 inch bottom lock nut.
      2) Unscrew the strainer drain body as seen from inside the shower stall. The notches in brass strainer body is designed to accept a drain wrench, but I think setting the jaw ends of channellocks would work in a pinch.
      3) Push/pull the drain body off the top of the PVC riser pipe.
      4) Install a Sioux Chief JackRabbit bolt-down no-caulk shower drain. This has an internal rubber gasket that fits over the PVC drain pipe and uses four bolts to secure it to the shower pan. It’s designed exactly for your situation where there’s no clearance to get a wrench on the 3.5 inch lock nut. Home Depot should have this item in stock for around $20.

      I would reuse or replace the top rubber gasket that goes between the top of the shower pan and the rim of the strainer body.

      Let me know how this turns out for you.

  2. Marc Nielsen March 24, 2012 at 3:58 pm #

    Hey Bob
    thanks for all your great advice. I have. A curious problem – I seem to have a shower that has no screw top to the drain! It’s just a hole with a rubber gasket that looks like it was stuffed full of silicone and the pipe underneath? Have you ever heard of such a thing? I am starting to think the builder used cheap materials and I may need to have a plumber tear this whole thing out! Help!

    • Bob Jackson March 25, 2012 at 10:08 am #

      My guess is you have a no-caulk shower drain based on the seeing the rubber gasket. Compare your drain to Mikes photos in the comment dated February 20, 2012 at 11:40 am in Part 1. Scroll down to the bottom of the post to see the comments.

      The “stuffed full of silicone” indicates an improper installation.

      If the above doesn’t help, you can e-mail photos to bob (at)

  3. Ellen January 13, 2013 at 6:20 pm #

    I’ve read through Parts 1 -8 and appreciate your step-by-step instructions and photos. Thank you for all your advice — you’re helping countless DIYers. However, when I went to the store to buy replacement parts, I hit a dead end. I can’t find the anti-friction washer or the rubber gasket I think I need to replace (water marks on first floor ceiling under upstairs shower). I’ve gotten the metal plate up and taken out the rubber gasket and anti-friction washer (which had pretty much disintegrated). None of the stores around carry replacement washers or gaskets. OK, so I figured I’d just buy the whole unit, but when I tried tofit the pieces together, the large plastic nut is too large. Instead of threading on and off, it just slips on and doesn’t thread. I’m at a loss and am going to start at Part 1 again. :(

    • BobJackson January 13, 2013 at 8:12 pm #

      Yeah, you have to buy the whole drain just to get the rubber gasket. :-(

      > but when I tried tofit the pieces together, the large plastic nut is too large.
      > Instead of threading on and off, it just slips on and doesn’t thread.
      Are you referring to the 3.5 inch lock nut? When you only have access from inside the shower, the lock nut should remain in place below the shower pan and you don’t need the anti-friction washer, only the rubber gasket. If you’d like to e-mail photos to bob (at) it would help me understand your situation. Replace the (at) with the @ symbol in the e-mail address.

  4. Ken Wall May 10, 2013 at 7:12 pm #

    Help! After reading this article I was ready to fix my leak, but after prying off the strainer I could not find a way to take this drain apart. It is made of brass and I can not see any lugs or indentations that will allow this to be turned. The brass seems to be two pieces, one above the other. What should I do?

    • BobJackson May 10, 2013 at 8:53 pm #

      > The brass seems to be two pieces, one above the other.
      You most likely have a “no-caulk shower drain“. Strange that you don’t have at least two notches in the compression ring to accept a drain wrench. Do you see any manufacturer or model # markings? You can e-mail photos to bob (at) Replace the (at) with the @ symbol.

  5. Cindy Gray July 16, 2013 at 12:06 pm #

    Help – Quick. My husband is losing patience and is threatening more caulk. We have what appears to be a Sioux Chief Model 827 No-Caulk Brass Shower Drain in a shower that was built in 2002 on a concrete slab and was caulked under the lip of the brass drain – no shower pan gasket. The owners that built the house had a leak immediately and the builder sent a plumber who caulked and replaced a baseboard. 2013 – still slow leaking with more baseboards expanded. I have the compression nut out, can see the compression gasket on pvc pipe end and the pipe end is not cut on a 90 degree angle. It has a slant. Is there a locking nut under the drain? How would they do that under the shower pan with about 2-3 inches clearance? How do I get this drain out? I am planning on removing everything and using a wingtite drain, as that is about all I am capable of doing. I went to the plumbing supply to look at drain assemblies, they looked at me and said, “Call a plumber.” My Daddy was a plumber and I can do this…with your help.

    • BobJackson July 17, 2013 at 10:35 am #

      > 2013 – still slow leaking with more baseboards expanded.
      I’d be concerned about water damage to the 2×4 wall sole plates, baseboards and mold. The sole plate is base of the wall that’s fastened to the concrete slab. Caulking the baseboards is a bad idea because it can hide a shower leak until things get really bad. Best to remove the baseboards, inspect the wall, treat any mold problems and let everything dry out.

      > Is there a locking nut under the drain?
      I’m guessing you have a plastic shower pan and plastic (versus brass) shower drain, correct? For a no-caulk drain, there should be lock nut screwed on the shower drain body to hold it against the bottom of the shower pan. The drain body and lock nut were installed before the shower pan was set in place, which makes it very difficult to access the lock nut and remove the drain.

      A less expensive retrofit method is:
      You’ve already removed the compression nut and rubber compression gasket from the top of the drain. Good.

      As shown in the WingTite installation video:
      * Use a hacksaw to carefully cut a small wedge or section in the plastic drain body. Video timestamp 1:52 to 3:03.
      * Break the silcone seal between shower pan and drain flange. Video timestamp 3:07.
      * Turn the drain body counter clockwise which will unscrew it from the lock nut on the bottom of the pan. Video timestamp 3:12 to 3:54

      Once the old drain is out, clean the drain pipe and shower pan, then install the WingTite in the normal way.

  6. Melinda Beyers August 8, 2013 at 7:52 pm #

    Hi, I read through all the steps for repairing a leaking shower drain and have hope! A good ten years ago I replaced the tub in the second story bathroom with a walk-in shower. Ignorance is bliss! I’d purchased the Corian shower walls and floor when the Home Base store closed – but it the shower parts were a floor model and not intended for installation. There is no shower pan and the corian floor is level, requiring that I squeegee the floor as well as the walls to ensure there is no soap build up that makes for a very slippery shower floor.

    My handyman/contractor took on the challenge but the shower has leaked off and on all this time. My son tightened the drain and that helped for a while, then my nephew the plumber had a go at it and that helped for a while. But the shower always goes back to leaking. I keep a large bowl in the closet cupboard below the ceiling hole the contractor made (and thankfully, we never patched) to catch drips, but seepage keeps the plaster wall in the main floor hall and the ceiling in the powder room and my music studio wet. My new paint job in the powder room has bubbled and cracked.

    After reading your repair steps, I’m pretty certain the problem is only with the drain and I have confidence I can repair it myself now. However, I thought I’d ask whether you think the seams where the floor meets the walls might also be leaking. My son is a glazer and has applied new silicone caulk twice, but after two to three years, black mold always begins to grow under the silicone caulk.

    I’ve also wondered whether the corian floor is simply too thin for a good seal with the drain. What is the thinnest the floor should be? And I’ve wondered whether I might kill three worries with one fix by installing a tile floor over the top of the corian. I could build in more slope for better drainage, the mastic and grout for the tile might seal the seams with the wall ending that concern, and the mastic and tiles would thicken the floor ensuring a better drain seal.

    Lastly, if you want to take a trip to Portland, Oregon, and let me be your helper with this fix, I live in a southeastern suburb, right on a good stealhead river!

    Thanks for taking the time to read this and hopefully, to respond;
    Gladstone, OR

    • BobJackson August 8, 2013 at 9:06 pm #

      > However, I thought I’d ask whether you think the seams where the floor meets
      > the walls might also be leaking.
      A quality mold-resistant silicone bath caulk should make a watertight seal, however mold will grow on latex caulk because Latex has tacky surface. Given that the Corian floor is not sloped for drainage, the persistent dampness will promote mold growth.

      > I’m pretty certain the problem is only with the drain
      It should be easy to verify the drain is leaking since you have a hole in the ceiling. Saw a larger opening in the ceiling drywall if neccessary to see what’s going on. Cut the smallest hole possible so you can later make it the proper size for either an access panel or ceiling repair.

      > I’ve also wondered whether the corian floor is simply too thin for a good
      > seal with the drain. What is the thinnest the floor should be?
      The floor should be strong enough to support your weight when standing close to the shower drain with minimal flexing. If the shower floor flexes a perceptible amount it can crack the drain flange and work the lock nut loose. A Corian countertop is fairly thick and rigid, but I don’t know about your Corian shower floor. Corian normally isn’t intended for foot traffic. Since it’s not sloped for drainage, I’d replace it with a proper shower pan.

      > installing a tile floor over the top of the corian
      That could work but I can’t think of a presentable method to install a shower pan liner run up the Corian shower stall walls without creating an eyesore. The shower pan liner prevents leaks where the tile meets the stall walls. The best way would be to:
      * Remove the Corian shower stall walls.
      * Remove the Corian shower floor.
      * Build a shower stall and curb.
      * Install the shower pan liner, mortar bed and drain. The shower pan liner will run up the 2×4 wall for 6 to 8 inches (I don’t remember the exact minimum distance.)
      * Tile the shower pan.
      * Install the Corian shower stall walls. The shower pan liner run up the walls behind behind the Corian.

      See Finishing a Basement Bathroom for building a tiled shower pan.

      Overall, it may be less expensive and quicker to either buy a manufactured fiberglass shower pan – no need for tiling! – or tear everything out and start from scratch since it might not be possible to avoid damaging the Corian stall walls.

      Let me know what you do.

  7. Jim January 12, 2015 at 11:39 am #

    Bob & T. Sparks, Thanks for this posting. It (and the pictures) is the only hit I got for the exact drain I also have. Mine is installed along with an ELM Model 99 DURAPAN Washer Pan, which I am trying to replace with a larger pan now that we have a new and larger washer.

    A couple of things to note: 1) Earlier, this posting states, “I searched the Internet but was unable to find the manufacturer or drain model.” The manufacturer is E.L. Mustee (see: and the drain model is “42-304”. 2) Also stated earlier is, “The strainer body is threaded and therefore screws into the solvent weld shower drain body.” If I’m understanding the statement, this is incorrect. This drain is one solid piece; there is not a separate strainer and drain body. Though it has cutouts for a drain wrench, these are only for providing counter-torque when also turning the 3.5″ Lock Nut.

    Other than as a homeowner addressing a home repair job, I have no prior experience with this drain. So, to confirm my suspicions, I called and confirmed my above statements with a Mustee technician.

    Without cutting a hole in the ceiling and accessing this drain from below, I (unlike T. Sparks) only have access from above. So, for anyone with a job similar to mine, here’s what I plan to do. I will cut the 2″ PVC DWV from the inside of the pipe (using something such as a Dremel with a cutting bit) just low enough to cut below the lowest part of the drain body. Once cut/separated from the 2″ pipe, I should be able to lift away the entire washer pan and attached drain. I fully expect I’ll need to extend the 2″ PVC pipe to its original length. If so, solvent welding a collar and 2″ pipe extension onto the pipe I cut should suffice. At this point, the remainder of the job should be no different than if a drain were being originally installed.

    One thing’s for sure, the replacement drain I choose won’t be one that makes replacing a drain pan so involved!

    • Bob Jackson January 12, 2015 at 12:54 pm #

      > I will cut the 2″ PVC DWV from the inside of the pipe (using something such
      > as a Dremel with a cutting bit)
      That could work. Or try a PVC/ABS inside pipe cutter:

      > One thing’s for sure, the replacement drain I choose won’t be one that
      > makes replacing a drain pan so involved!
      Take a look at the WingTite shower drain that installs from the top of the shower pan. I’ve no experience with the product but it may be what you’re looking for.


    • John Goeb December 28, 2015 at 1:18 pm #

      The information provided buy (Jim January 12, 2015 at 11:39 am # ) is correct for the E.L. Mustee & Sons drain part number 42-317. (Mustee, the manufacturer lists this as 42.317A). Mustee no longer provides any parts for this drain assemble and it is in fact a one piece design. The sell a replacement part Number 42.317A but the design is now different and requires access from the bottom of the pan to install so if your application is like mine a hole will need to be cut into the ceiling on the first floor. I have a PDF Drawing / image of the two drain assemblies side by side. I can send this to be attached if I get an email of where to send.

      • Bob Jackson December 28, 2015 at 8:44 pm #

        Send the .pdf to bob[at], replace the [at] with the @ symbol. Or better email the link to the original source(s) on because I can’t post copyrighted documents/drawings.


  8. Will W January 21, 2015 at 11:25 pm #

    Hi Bob,

    Thank you for the great step by step instructions. My problem is slightly different from the pictures since I have a single story concrete foundation home. My master shower is leaking and I feel the drain is the culprit. The drain is a “no caulk” brass drain. It’s about 8 years only and I’m wondering if I should try to change out the compression gasket or just put some caulk or putty in and try to tighten down the nut really good. I gather from the previous posts that I will likely need to buy a new unit just to get the gasket.

    Thanks for the help!

    • Bob Jackson January 22, 2015 at 12:25 pm #

      Replacing the compression gasket is the best option. I doubt caulk would work and just make it more difficult to replace the compression gasket.

  9. Andrew L January 23, 2015 at 4:08 pm #

    Hi Bob,
    Great posts, I appreciate your willingness to help out. After discovering a leak at our shower drain, the problem I’m facing is the fiberglass shower pan, where from underneath the drain hole is a sharp edged circle, with the edges only about 1/8″ thick, rather than flat surface to better accommodate the gasket for a proper seal. The shower itself might be original to the house (30 years), and while we want to renovate someday, the timing is not quite right to switch the whole thing out. I have not found any other type of shower drain that might be better suited for use with the design of the shower pan; should I just go ahead with the regular shower drain, applying silicone or putty both above and below the shower pan, and hope for a good seal? I would be happy to send along a photo of the bottom of the shower pan if that would help.


    • Bob Jackson January 23, 2015 at 8:10 pm #

      Hi Andrew,
      I don’t recommend silicone caulk against the bottom of the shower pan because it makes future repairs very difficult. After 30 years it’s probably best to replace the drain. It shouldn’t be too difficult because you have access to the bottom of the shower pan.

      Photos would be very helpful to understand the type of shower drain and the best approach to repair or replace it. Send photos to bob[at] – change the [at] to the @ symbol.


  10. Ann in VA August 24, 2015 at 1:43 pm #

    Big problem! Noticed ‘bulging’ in ceiling plaster directly under master bath. Plumber, today, cited leak as result of faulty drain install when we converted fiberglass surround to all tile shower appx 8 yrs ago. He advises we tear out the tile floor, portion of the tiled walls (to release shower pan), the shower pan, and the drain! And then replace everything…Yikes!!!

    Having known the contractor all my life, I do know there is no ‘pre-fab’ shower pan, but a laid-in mortor base. I’m also not too certain he is correct about them not replacing the drain during the original remodel, as we had a new drain ‘cover’ so I would assume a new drain accompanied it (???)

    At this point, I don’t know where to turn. Bottom line is there IS obviously a leak that needs fixing, but how do I know if we truly have to go to this extreme to fix it???

    • Bob Jackson August 24, 2015 at 10:15 pm #

      Other readers have faced a similar situation as yours: tiled shower drain is leaking and the contractor recommends an expensive tear out and replacement. This may be required but it’s worthwhile to diagnose the specific leak source and maybe remove only the tile and vinyl liner around the drain. See my prior recommendations here starting at the 5th paragraph:

      “You may be able to locate the leak source with a flexible inspection camera inserted through a small hole or two through the drywall ceiling. If the drain or drain pipe connection is found to be leaking, it’s possible with careful work to remove the tile and mortar bed around the drain, remove the drain, install a new drain, redo the mortar bed, cut and glue in a new piece of shower pan liner and replace the tile. That should cost way less than $2500 to tear out the entire shower pan.”

      Let me know what you find and decide to do.

Leave a Reply