StyleGuard® Fixed Window Installation Instructions

For Picture, Casement Picture, Transom and Geometric Windows (Also similar instructions for StyleGuard® Hung Windows)



STEP 1: Prepare the Opening

Note: Installation of fixed windows with nail fins is the same as that for double hung, except for operation of moveable window sashes that are not on fixed windows.

  • Ensure the rough opening is 1/2” larger than the window to be installed and that the rough opening is plumb and square. See Detail 1.

Note: The frame size of the window does not include any protruding nail fins.

  • Close and and lock the sash(es) to help keep the unit square.
  • Apply flashing to the sill. See Detail 2.

  • Apply a continuous bead of silicone caulk to the perimeter of the rough opening where the nail fin will make contact (no more than 1/4” from the edge of the rough opening.

STEP 2: Install the Window

  • Place 1/4” shims at either end and at every 12” maximum on center of the level sill plate. Place the window in the rough opening from the exterior, and center the unit in the opening, leaving a 1/4” gap between the unit and the rough opening on all sides. See Detail 3.

  • Secure the unit by loosely fastening through the center of one nail slot at the top of one of the jambs using a #10 pan head stainless steel screw. See Detail 4.

  • Check to ensure the sill is level and shim as necessary at the sill ends.
  • Ensure the frame is plumb and the jambs straight. Shim at the top, bottom, and midpoint to correct any deflection.
  • Take diagonal measurements to ensure the unit is square. Opening the bottom sash approximately 1/4” will provide visual confirmation of proper setting, that the reveal between the frame and sash (A & B) are equal the entire width. See Detail 5.

  • Finish screwing the unit using every other slot as a minimum (every slot for DP50 or greater. Use #10 pan head stainless steel screws capable of penetrating 1-3/4” into the framing structure.
  • Ensure jambs are not bowed and head and sill are not crowned up or down. Operate window to confirm proper installation.

STEP 3: Finishing

  • Apply flashing the perimeter of rough opening, covering the vertical nail fin. Apply the flashing at the head and overlap the jamb flashing on both sides. The head flashing should be caulked or taped on the top edge. See Detail 6.

  • Use fiberglass insulation to insulate the cavity between the window and the rough opening structure.


  • Do not use expanding or spray-in foam products. If the installer used one of them, make sure jambs remain straight to ensure the operation of the window is not impeded.
  • If using brick or stone exteriors, leave a 1/8” gap from the window to allow for brick and mortar expansion. Use a backer rod and silicone caulk to seal the gap.
  • Do not use brick wash after windows are installed. Doing so will void the window warranty.
  • Windows should never be stored in an area where temperatures will exceed 140° F. Doing so will void the window warranty.
  • Windows should never be painted. Doing so will void the window warranty.

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