Should I follow the manufacturer’s recommendation of using plumber’s putty to seal the drain strainer in my fiberglass bathtub, or should I use silicone to avoid potential pipe failure?
Asked by Bryan Hunt 
2 weeks ago
Last Updated: May 4, 2024
Hey everyone,
I was looking at the instructions for my fiberglass bathtub, and they mention using plumber’s putty to seal the drain strainer. However, I’ve heard that putting putty on an ABS pipe (which is what my drain is made of) can cause the pipe to deteriorate over time.
Should I follow the manufacturer’s recommendation and use putty, or should I play it safe and use silicone instead?
Silicone will deteriorate over time as well. Silicone caulk is not suitable for plumbing tasks. Was there a rubber gasket included with your drain for sealing between the drain flange and the shoe? You shouldn’t require anything else.
It’s strange that they recommend plumber’s putty. Manufacturers advise against using it in this situation due to potential damage to plastics and staining of fiberglass, even with the “stain-free” kind
For a durable solution, opt for a quality rubber gasket
When it comes to , that’s where I got confused. I even reached out to the manufacturer to double-check. I spoke to an older representative who wasn’t quite sure but mentioned using putty and avoiding silicone. And yes, it did include a rubber gasket.
You really only need the gasket, unless you want to use putty on the top side of your drain flange. But be careful, it could stain the pvc/enamel. Also, it’s strange that there isn’t a compression ring below the gasket to prevent it from deforming when you twist it in.
Make sure to put the gasket under the tub and the putty above it. Avoid using silicone and always opt for putty instead.
Yeah I see what you mean. The drawing does illustrate that. Normally, there’s a metal compression washer placed between the shoe and the gasket to ensure that the pressure is distributed evenly when tightening the shoe. Without it, the PVC can stick to the rubber and cause the gasket to deform.
I’ve always followed the same method for installing fiberglass tubs, like I described earlier, and I’ve never had any issues. In fact, I used the same technique in my own home five years ago, and there have been no stains, discoloration, or leaks.
Hey Steve, I totally get where you’re coming from. We’re on the same page here. I’m just wondering why the OEM didn’t include a compression washer between the shoe and gasket.
Sounds like you’ve been pretty fortunate so far. Good to know, thanks for the advice.
Hey, you really should stick to the manufacturer’s instructions, buddy. Plus, I’ve got 20 years of experience under my belt. Fiberglass tubs tend to have imperfections which is why putty comes in handy.
Hey, got a message from Oatey for you. “Just a heads up, both stain-free and regular plumber’s putty could mess with the finish of acrylic surfaces, so avoid using them when setting up the drain on an acrylic tub and/or shower unit. It’s best to stick with 100%-silicone for this job.” Hope this helps! 😉
I totally get why you’re confused about what to use! 😂 The tub instructions recommend one thing, while the putty instructions advise against it and suggest using silicone instead. However, silicone is not meant for tub plumbing…
You actually don’t need a compression washer because the rubber washer goes beneath the tub, and the drain screws in from above. This means there is no twisting motion against the rubber, just between the putty and the tub. Basket strainers, on the other hand, typically have a compression washer because tightening the strainer down can cause the nut to rotate against the rubber washer, potentially deforming it. The debate over putty versus silicone will likely never be fully resolved. I personally use either depending on the situation or availability, except when it comes to disposals. The vibrations can cause putty to crack quickly, so I always opt for silicone in those cases.
Make sure there is a gap between the drain assembly and the fiberglass opening to avoid contact with the drain pipe
I’ve always used plumbers putty, no exceptions.
I would definitely apply the putty as indicated, even if it’s a fiberglass tub. The putty won’t affect much, just the thread throat and the area under the tub lip that’s covered by the tub nut, which is not visible anyway. I dislike using silicone for this purpose, especially when removing a tub nut that has been sealed with silicone for 20 years is a real challenge. And are you certain that the tub shoe is made of ABS? From my experience inspecting numerous tubs in various homes, it’s more common to find PVC, brass, or cast materials, although it could eventually connect to ABS.
I always use plumbers putty, just like in the drawing. It works really well, and I’ve never had any problems with it.
I work as a plumber with experience. Last night, when I changed the drain in my tub, I opted for putty. Honestly, either option would likely work fine. I prefer putty because silicone can be messy to put on. Plus, the gaskets don’t always create a tight seal for me.
How about the impact of putty on abs pipe?
Oh, really? That’s new to me. Not saying it’s false. But I haven’t heard or seen that before.
I’ve never seen a plastic tub drain and overflow. They are usually brass and then transition to a PVC drain. Plumbers putty is used to seal the drain and doesn’t impact the drain itself.
I actually bought this one straight from American Standard, it’s made of ABS pipe.
The instructions for the putty specifically mention avoiding contact with porous materials such as granite or marble.
For clear silicone, make sure it’s snug and leave it for 24 hours. It’s fail-safe if done correctly.
I’m not a plumber, but I’ve always relied on putty. It’s simple to use and easy to clean up. It may not last forever, but I’ve had it last for over 15 years.
Make sure to always use plumbers putty!
Stop worrying so much about it. Put putty on the tub side and silicone on the bottom side. You won’t be around long enough to see any negative effects from the putty, and you won’t experience any leaks either.
When applying the putty, shape a ball in your hands until it’s smooth and malleable. Roll it into a snake-like string and wrap it around the top flange of the fitting. It will squeeze out when you tighten it. If you’re having trouble picturing this, just ask any 7-year-old with play-doh.
Is such a troll. He always has to act like a know-it-all when someone asks a question.
I always opt for putty in this situation and have never encountered problems. The inexpensive drains you find at major retailers always seem to deteriorate before the putty gives out.
Go with putty and you’re good to go.
Since the putty forms a seal between the strainer and the tub without coming into contact with your abs, I don’t understand your concern.