The horizontal seam between two panel siding boards should have what kind of flashing?

Answer 1

You are looking for "z" flashing made just for such applications. It is available at Lowe's, Home Depot, and any local lumberyard. Although vinyl z flashing is available, spend the extra money for aluminum. The vinyl type is very thin and it will start to break apart in just a few years.

Caulking will not do the job. In addition to being unsightly, it will quickly fail in this application and your siding will be damaged in a hurry.

Good luck with your project.

Answer 2

bead of caulking