3 1⁄2″ Exterior Casing

Alliance Vinyl Windows offers a 3-1/2″ Exterior Casing option on our Windgate new construction windows and patio doors.


  • All welded corners
  • Windows come with 3-1/2″ Casing on the head, sill & jambs (bull nose sill style is not available)
  • Patio Doors come with Casing on three sides – head & jambs (not sill)
  • Extruded White or Tan
  • Exterior Paint Colors Available
  • Trim color can match or contrast the window color
  • Mechanically mounted and sealed at the factory
  • Extruded in “J” channel to accommodate 3⁄4″ butt height siding
  • 2″ Nail Fin
  • Casing can be bent (but is limited to a radius no smaller than 17.5″)
  • Can be mounted on mulled window units

The 3-1/2″ Exterior Casing adds to the initial material cost of the unit compared to other casings. However, since the Casing is factory applied there are offsetting labor advantages. When compared to siding casings, which are not welded; trim boards, that often need painting and/or capping; or other snap-on trims, as well as their installation, pricing is competitive and aesthetics are improved.

Installation Notes:

  • The Casing’s nail fin is extends beyond the body of the window by about 3- 1/2″ so attachment may miss the 2×4 or 2×6 studs around the rough opening. To ensure the nails adhere to the studs, rather than just the sheathing,
    additional studding or scabbing will be required when framing the rough opening
  • We recommend, in addition to attaching the nail fin, that the installer also adds installation screws through the inner balance track (like a replacement window)
  • Standard house wrap installation instructions apply

Other Considerations:

  • In order to avoid excessive rippling on the exposed 3-1/2″ face, there are radius limitations for architectural shapes
  • The Casing adds up to 10″ (with packaging) to the width and height of the finished window. Due to truck dimensional limitations this further restricts maximum window sizes that can be produced and shipped with the 3-1/2″ casing
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  • Thermal Performance

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  • A variety of color options!

    A wide range of interior, exterior and woodgrain options. Learn more.

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