I have a leaky trap in my shower drain. I was told today to use silicone instead of plumbers putty. It is a fiberglass tub/shower unit and he said it will bond better and create a better seal.

If your trap is leaking neither is the correct fix. Traps employ nylon washers and yours may have failed, Replacing the washer is the correct fix. https://www.youtube.com/watch?v=qAfO66ONkZM

That and drains tend to have soap deposits that would inhibit anything from bonding well. Best to fix it right the first time. Leaks tend to become very expensive if not stopped quickly and permanently.

Hi Andy. My guess is that you are referring to the shower STRAINER? If this is the case, and the shower floor shows there is a "flexibility" in the shower floor, then silicone is definitely the best bet. Otherwise, if the shower pan is rigid, plumber's putty or silicone caulking works fine, either way!

Back to you...

Mark

Can you re-phrase "leaking trap" ? Leaking from a joint or corroded through pipe wall ? Perhaps, post a photo of it if you can.

In the interim:. If your trap is plastic and is glued together - than cut it out and install new trap. If your trap is washer & nut combination, than unscrew the two nuts, install new trap, new washers, and tighten the nuts. If your trap happens to be Cast Iron and it leaks - then loosen both Fernco fittings - one on each side of the trap - remove old trap, insert new one and tighten the Fernco couplings.5
No matter what kind of trap you have, it is relatively easy & inexpensive fix. Should take you 15 minutes to install new trap in place of the leaking one.

Putting silicon or plumber's putty over a hole in a leaking trap is like putting a chewing gum over it - in a hope it will stop the leak. It will seal the leak for day or two - and the same problem will re-appear. Do it right first time.

Hope that helps

Milo