Seal the gap between shower valve sleeve and escutcheon???

[Troutd0g]

In a recently completed shower rebuild, I used kerdi membrane for walls and floor and kerdi seal gaskets for the shower head and shower valve penetrations/openings. Great. The valve cover has a narrow foam gasket on the backside that presumably prevents water running down the wall from penetrating the wall cavity, and the kerdi seal gasket further prevents this because it has a rubber lip around the valve opening.

There is nothing preventing droplets of water that collect on the valve sleeve from dripping back to the valve and ending up in the wall cavity BEHIND the kerdi'ed wall that I worked so hard to make water tight.

Is it necessary and recommended therefore to seal around the valve sleeve - between the sleeve and the cover trim (escutcheon)?

Seems logical. Shouldn't lead to mold since water should never be getting into that cavity regardless under non-failure circumstances. Yet I've never seen this recommended.

 

[Jadnashua]

To get water in there would likely take a hand-held shower that you then directed straight onto the valve assembly. Any indirect splashes shouldn't be an issue. Personally, I've never had an issue relying on the stock gasket on the trim. You do want to be able to remove it for service to the valve when you need to replace the cartridge. That's usually a long time. That joint between the trim and the sleeve is usually pretty tight.