I regularly read your magazine but was disappointed with "Built-Up Hot-Mop Roofing" (2/05). The proper process for installing metal flashings on a built-up roof is to nail a fiberglass base sheet over a red rosin slip sheet with square-cap nails; mop the layers of field roofing with hot asphalt; coat the metal flashings with an asphalt-based roofing primer; trowel a layer of roofing cement to the underside of the metal flashings; mechanically fasten the flashings to the roof; install additional layers of ply sheet over the metal flashing details with hot asphalt; and seal the flashing with roof cement.
The photograph on the magazine cover illustrates improperly installed metal flashings. Under no conditions should flashings be installed directly over the base sheet. Additionally, the base sheet is not secured with the proper number of fasteners.
to continue reading