Thank you for your question. The instruction manual for the Delta 422061 shower unit indicates as follows:
"Caulk the outside of the shower enclosure where wall jambs meet the walls, the seam between the stationary panel and wall jamb, the glass meets the base, the glass support meets the base, and
the vertical section as shown. Allow sealant to dry and test that enclosure is water tight."
Here is a link to the instruction manual for the unit:
Date published: 2019-02-23