SHOWER DOME TRIM

[leeper]

In the shower ceiling below the dome is the shower garnish or trim. Some of these have a clear plexy glass on top. Alot of these do not have it. Replacement garnish does not have the plastic since you need to rim the top to fit in under the dome. What is the purpose of the clear plastic and is it needed?

[path1]

(another hardly an expert) I think not only looks good but a moisture barrier of sorts.

[1ofmany]

Hardly an expert, but just a couple of observations...first, without the "clear" insert, any creatures that have made their way into your attic will have free access to your interior. Also, while not providing much additional insulation, there is some insulation value with the clear insert.