Materials & Construction
The ThermoMark 5255 features hot-dipped galvanized steel construction that is pre-painted prior to manufacturing with a two-coat system of polyester paint with a finished coat (includes primer). The inside and outside skins are roll-formed and separated with a thermal break to eliminate thermal conductance. Hinge locations have 20-gauge continuous back up plates for fastening. The bottom astragal is a two-piece “bulb” type astragal to be attached to the interior skin. Section ends have end caps of 18 gauge hot-dipped galvanized steel, and a between-section joint seal is standard.
*Wayne Dalton uses a calculated door section R-Value for insulated doors.