Inside casing is a flat, decorative moulding that covers the inside edge of the jambs and the rough openings between the window unit and the wall. Outside casing (or brick mould, above) serves the same purpose, while it also is an installation device through which nails are driven to install the window unit into the wall.
The pitch of a roof is the degree of the inclination upward from horizontal or flat. It may be expressed in degrees or as the ratio of the number of inches it rises in each 12 inches of horizontal span: 4/12 means the roof rises four inches in every foot of horizontal span.
The horizontal rough framing member, usually two inches by four inches, which forms the bottom of the rough opening. It is toe-nailed into the jack studs and is supported by cripples.R-ValueResistance to thermal transfer or heat flow. Higher R-value numbers indicate greater insulating value.