Window and door casing

DETAILED DESCRIPTION It is therefore an object of this invention to provide a window and door casing for use with new construction as well as remodeling that is simple to fit and install, will provide a durable, secure and complete aesthetic finished look, and will not be subject to differing thermal characteristics.
The trim casing is comprised of extruded portions or sections with an integral "J" channel built in providing superior aesthetic features; two side sections, a header or top section and, in the case of a window application a sill bottom section.
The sill also has caps attached at either end.
The trim casing is mountable on a window or door frame and is securely fastened to the side of the house ensuring a tight fit.
In the preferred embodiment, the casing is comprised of extruded vinyl, and comprises pre-mitered side sections and the header section include a rapid fastening system incorporating a screw boss in the extrusion coupled with a tongue-in-groove design on the inside edge which is received by an accessory groove (channel) with a flexing accessory lock incorporated on the sides of the window or door frame, and a nailing fin on the opposite side, and in the case of a window, an extruded attachable sill nosing which simulates the thick wood look having insertable end caps to cover the open ends and an integral flange to cover the meeting point of the side casing to the sill nosing.
A method of installing the casing consistent with the invention includes the steps of: in the case of new construction, first installing, leveling and squaring the window or door properly; securing the window or door by nails, staples or screws using the window's or door's nailing fin; pre-assembling the top section of the pre-mitered casing to the side casings, mating the angled ends thereof and then screwing the sections together; sliding the resulting three-sided "horseshoe" shaped assembly over the front of the window or door, the tongues of the assembly fitting into the accessory grooves located on the window or door frame