I'm putting in a drain onto a shower base and I have some butyl caulk laying around. It says "gutter and flashing" on it and I'm thinking since it is water proof...can I use it between the drain and top surface of the shower pan to seal it around the edges?

Here's the drain I'm using: https://www.amazon.com/EZ-FLO-30031-Strainer-Stainless-Steel/dp/B0006HCC9O/

My beginner-level understanding of installing this is essentially that the drain goes on top of the pan, the rubber gasket + cardboard ring on the bottom of the pan, and the nut tightens over that. My question is regarding what's between the drain flange and the shower pan.

I have read that silicone is used here normally, but I'm not sure if butyl caulk would suffer decreased performance.


  • 1
    I'm not entirely clear on what you're referring to by "between the drain and top surface of the shower pan". Can you post a photo? If you're talking about the drain flange, these would typically be installed with a rubber gasket (which should have come with the flange). I've never seen any caulking used to install a flange - a more typical non-gasket install would be plumber's putty.
    – Comintern
    Commented Mar 3, 2019 at 22:27
  • @Comintern I've added a link to the product that has photos and a description of what I think is going on. Hope that helps!
    – Joe B
    Commented Mar 3, 2019 at 23:42

1 Answer 1


I can't locate the installation instructions for that particular model, but it does appear that the gasket is intended to go underneath the pan. If the manufacturer has a recommendation, I'd obviously use that. If that's the case, I'd go with plumbers putty as opposed to butyl caulk for a couple reasons.

First, butyl caulk isn't particularly dimensionally stable - that is, it will have a tendency to shrink over time. Second, it is incredibly difficult to clean up. That means if lay you down a bead of butyl and then clamp the the flange over it you will force some out onto the floor of the pan (and if you don't, you didn't put enough on).

What you'd likely end up with is a mess that you might not be able to clean up without damaging the finish on pan itself with the solvents you'd need to get the stuff off. Silicone, on the other hand, will generally just peel away or come off with light friction (like rubbing it really hard with your thumb), and plumber's putty doesn't really "stick" so it's the easiest to clean up after.

Finally, the last reason I'd steer away from butyl is that it usually takes a long time to fully cure (the last one I used was labelled as 7 days to a full set). This is fine in a gutter where you don't have people walking on it, but probably less so in a shower unless you're willing to sit it out.

Plumber's putty is specifically made for this type of application, and it's so cheap that it really doesn't make a lot of sense to go through the potential hassle to avoid spending a dollar or two just to use up a tube of butyl that you have lying around. The gasket on bottom is doing the majority of the work anyway - about all the seal on the top does is stop water from standing inside the cutout on top of the gasket.

  • Thanks! I bought some plumbers putty. Is there a limit to how much I can compress it before it loses its water tight seal?
    – Joe B
    Commented Mar 4, 2019 at 19:33
  • @JoeB Not really (it's mainly just an filler material) - torque away.
    – Comintern
    Commented Mar 4, 2019 at 19:40

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