We built a pergola that has 2' x 2' concrete footers - the holes were dug and posts put in place, surrounded by cement 2' around and 2' deep. They put some removable foam between the cement and the posts. The pergola guys finished off the trim around bases of the pergola posts, and the spray deck people will be coming soon. Should I remove the trim pieces around base of posts so they can remove the foam, and seal with the mastic, to A.) prevent water from getting in and, B.) make sure the spray deck gets applied to where it'll be covered by the trim pieces.

Thanks!