How to Fix a Leaky Shower Drain – Part 7

How to Fix a Leaky Shower Drain – install the new rubber gasket, strainer body and seal the drain to the shower pan with silicone caulk. This project is continued from How to Fix a Leaky Shower Drain – Part 6.

Leaky Shower Drain Repair

After disassembling the cleaning the shower drain, we inspected the drain body, strainer body and shower pan for cracks or broken parts. Finding no damaged parts we made a trip to Home Depot to buy a new drain because we needed a new black rubber gasket; you have to buy the whole drain just to get the gasket.

Here’s the shower drain cleaned and ready for reassembly:

Leaking Shower Drain Repair: Cleaned and Polished Shower Drain

Leaking Shower Drain Repair: Cleaned and Polished Shower Drain

Cause of Shower Drain Leak

Notice the fiberglass shower pan is approximately 3/8ths inch thick at the drain hole as indicated by the red arrows in the above photo. By comparison, my shower pan is about 1 inch thick at the throat. This is very significant because plumber’s putty is much more likely to squeeze out around the black rubber gasket on this homeowner’s thinner shower pan whereas on my much thicker shower pan, the plumber’s putty simply fills the void within the threads of the strainer- and drain body before it reaches the rubber gasket.

The homeowner confirmed the shower drain was originally installed by the home builder with plumber’s putty when it first started leaking. The leak was caused by aging and brittle plumbers that lost its “grip” over time (10 or 11 years) as the shower pan flexed from a person’s weight. This allowed the strainer body work ever so slightly loose, relieving compression on the black rubber gasket and thus began the water leak.

When the homeowner attempted to repair the shower drain, he used an excess of plumber’s putty which squeezed out around the rubber gasket, interfering with it’s function and pushed the gasket off center. The other problem with plumber’s putty is it continues to squeeze out over time because it’s packed against the rubber gasket, relieving the pressure on the gasket and the shower drain leaked.

The purpose of plumber’s putty isn’t to make a watertight seal when applied to the shower drain, rather it’s prevent the strainer body from unscrewing and relieving pressure on the rubber gasket – think of plumber’s putty in this application as a “thread locking” agent.

The other way to install a shower drain is to seal it with silicone caulk. Sioux Chief is a manufacturer of shower drains sold by Home Depot which instructs to use silicone caulk instead of plumber’s putty. The silicone caulk keeps the shower drain tight.

Shower Drain Installation

The homeowner purchased a tube of GE Silicone 1 100% silicone caulk for bath/kitchen/plumbing at Home Depot with a new Sioux Chief shower drain. We used only the black rubber gasket and metal strainer from the Sioux Chief drain because the strainer body threads are incompatible with the Plastic Oddities PFG600 and nearly identical ProFlo PFP600 course thread drains.

Shower Drain Repair: Install the New Gasket and Strainer Body

Shower Drain Repair: Install the New Gasket and Strainer Body

Insert the black rubber gasket between the shower drain body and bottom of the shower pan as shown in the photo below. Note the plastic anti-friction gasket was not installed because the homeowner will be in the basement holding the pipe from twisting as the strainer body is screwed in.

Apply a bead of 100% silicone caulk to the recessed rim of the shower pan drain hole. Do not use latex caulk because it can become brittle and is subject to attack by mold and mildew.

Apply a Bead of Silicone Caulk to the Shower Drain Recess

Next, screw in the shower drain strainer body until it’s hand-tight and firmly seated – however, it’s not yet tight enough! I used a large pair of channel locks against the two inside nubs to tighten it an extra 1/2 to 3/4ths turn or so to compress, but not crush, the black rubber gasket for a watertight seal. Wipe off the excess silicone caulk.

Screw in the Shower Drain Strainer Body

Screw in the Shower Drain Strainer Body

A new metal strainer is installed and fastened with two screws. Be careful not to drop the screws down the drain.

Reinstall the Shower Drain Strainer

Shower pan bottom and shower drain after reassembly:

Leaky Shower Drain Repair: Shower Drain and Shower Pan Bottom

Leaky Shower Drain Repair: Shower Drain and Shower Pan Bottom

Drywall Ceiling Water Damage Repair

Since the basement room was mainly used for recreation and storage, instead of an extensive drywall repair, I suggested a plastic access panel to cover the hole in the drywall ceiling as a quick and easy way to cover the damage. A 9in x 9in Watts SpringFit Access Panel at the local hardware store was the closest size and has the benefit of fitting over jagged holes. The SpringFit has a spring-loaded tongue on back that automatically adjusts to fit a wide range of openings. A bauco drywall access panel would be a really nice solution, too.

WATTS SpringFit Access Panel

The Watts SpringFit access panel is test fitted over the jagged hole in the ceiling. The homeowner will install a thin wood reinforcing strip above the ceiling to provide reinforcement and backer for drywall spackle to fill the small gap on the left. Now only light spackling and sanding is needed before painting.

Trial Fitting the Watts SpringFit Access Panel

See How to Fix a Leaky Shower Drain – Part 8 for a new shower drain repair issue sent in by a HandymanHowTo.com reader.

Hope this helps,

Bob Jackson

Copyright © 2016 HandymanHowTo.com   Reproduction strictly prohibited.

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6 Responses to How to Fix a Leaky Shower Drain – Part 7

  1. Mary November 5, 2011 at 2:47 pm #

    Thanks for the info! The only thing I don’t know how to “work through” is that our shower sits on a basement floor…should I use the anti-friction gasket since it cannot be held in place from below?

    Sincerely,
    Mary Ann

    • Bob Jackson November 5, 2011 at 3:22 pm #

      You only need the anti-friction gasket if screwing on the lock nut from below the shower pan – or – when installing a new drain for the first time because the drain body is screwed on from the bottom. For “old work” the anti-friction gasket is not necessary when screwing in the strainer drain body from inside the shower stall.

  2. Dave November 5, 2011 at 7:54 pm #

    Thanks for the informative information, this was spot on. I too had a leak caused by the original plummer using plummer’s putty, this caused the gasket to harden and of course the plumber’s putty got hard then worked it’s way under the hardened gasket and caused a leak which later turned into a moldy mess. I purchased a new gasket by buying the drain from home depot.

    thank you

  3. Zak November 12, 2011 at 9:16 pm #

    Thank you Bob Jackson!! You have no idea what a help this section was to help fix my leaking shower drain, im usually very lazy and never actually go back and reply/thank after getting helpful hints from forums or websites but this really was worth it!

    You saved me over a $100 and more than that i actually learned a lot and felt great after completing this since im not very good at DIY stuff :(

    It used to leak like crazy and before this i had NEVER done anything related to plumbing or pipes but your DIY gave me the guts and it seems as if i have fixed it as i turned on the shower for over 15mins straight and NO leaks(not even a drop) but wont be a 100% sure until a few days to make sure it doesnt leak after which i will fix the drywall also per your DIY!(fyi: i kept the non-friction cardboard ring because i tightened from the bottom)

    My only question is that i applied plumbers putty like you said around the strainer up top and on the threads to keep the 3.5″ nut from getting loose and then read that its not recommended, is there any serious concern for me or is it just that it will cause some staining?(which i dont care about)

    May god bless you!

    And once again Thank you

    • Bob Jackson November 13, 2011 at 8:38 am #

      > My only question is that i applied plumbers putty like you said around the strainer up top
      > and on the threads to keep the 3.5″ nut from getting loose and then read that its not recommended,
      > is there any serious concern for me or is it just that it will cause some staining?(which i dont care about)
      Let’s break this down:
      1) Plumber’s Putty on the Strainer Body threads:
      My shower drain is made by Plastic Oddities who said Plumber’s Putty or silicone caulk is fine when I called them. Sioux Chief’s installation instructions usually call for silicone caulk. Always follow your manufacturer’s recommendations.
      2) and on the threads to keep the 3.5″ nut
      Do not put Plumber’s Putty or silicone caulk on the 3.5 inch lock nut. It serves no purpose here.
      3) or is it just that it will cause some staining?
      Plumber’s Putty contains oils that can stain granite and attack some plastics and rubber materials. PVC shower drains and PVC pipe are highly chemical resistant and Plumber’s Putty won’t bother these.

  4. Mike Gallagher March 11, 2016 at 7:43 pm #

    Hello
    I have a general question about a leaking, 2nd floor shower drain. The drain assembly is a stainless steel Oatey model with a heavy rubber gasket that fits into the drain body over the 2″ pvc pipe. The shower basin is either fiberglass or hard plastic.
    The heavy rubber gasket appeared a little corroded on the top and I was able to remove with a screwdriver. It has threads on the inside which is in contact eith the pvc drain pipe.
    The top part of the drain body that makes contact with the shower basin appears to be tight.
    Is it possible to just replace the heavy rubber gasket only? I’m just trying to avoid cutting an access hole the drywall in the kitchen below.
    Thanks
    Mike

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