I am having an issue with my tub diverter. There is a small gap where I can’t get the diverter to sit flush with the trim piece. Maybe an 1/8 of an inch if that. I loosed the nut that holds the push on diverter in place and tried to get it to sit flush to no avail. The pipe doesn’t seem to be too long when I removed the diverter. Maybe it isn't perfectly perpendicular to the wall? I was thinking of putting some black silicon in the gap. Or do you think I should get a plumber out to address it? I just don’t want to get any water seeping into the gap and finding its way behind the wall. Thanks for your suggestions.

Images: https://imgur.com/a/k05zhRk

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  • If you haven't tried it yet loosen the set screw and twist back and forth slightly while pushing . If the spout won't go all the way to the wall, use the black caulk on the to and sides. Leave the bottom open so any water that may get behind can drain out.
    – RMDman
    Commented May 4 at 13:15
  • Instead of silicone I would put MS polymer on it (it's more durable, if needed you can apply more on it). Use alcohol 80 or 90° with your finger to make it smooth at the end and to remove uncured residues (⚠ wear gloves)
    – JinSnow
    Commented May 5 at 13:10

1 Answer 1


It is normal and customary to caulk the top and both sides (leaving the bottom open or at least with a gap in the caulking on the bottom for drainage should anything get in there despite the top and both sides being caulked.)

In this case I'd caulk both the joint you highlighted and the trim piece to the tile, leaving the bottom of each un-caulked.

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