How long have you been wondering why the drain holes formed by BuiltWithFoam.com have changes to the perimeter height? Set back and relax as we explain why we are so proud of the drain holes formed into our custom shower pans.How long have you been wondering why the drain holes formed by BuiltWithFoam.com have changes to the perimeter height? Set back and relax as we explain why we are so proud of the drain holes formed into our custom shower pans.