The Installation

Tools Required

  • Caulking Gun
  • Putty Knife
  • Utility Knife
  • Staple Gun


  • 100 Feet of HomeFlash
  • 12 Tubes of HomeFlash Sealant


  • Window Sill Pan Flashing
  • Door Sill Pan Flashing

Step 1:

  1. All rough openings shall be framed in accordance with the window manufacturer’s specifications. (vertically plumb, level and square)
  2. Surfaces shall be clean, dry, dust-free and free from any loose particles that could interfere with adherence. Contact manufacturer regarding compatibility guide lines

Step 2:

  1. Cut a length of HomeFlash (30.48 cm or 12 inches)
    longer than the rough opening sill

Step 3:

  1. Staple HomeFlash skirting to the exterior surface
    of the sub straight ensuring:
    • The foam side is inward facing, sitting flat against
      the sub straight “parallel and above the rough
      opening sill plate”
    • The HomeFlash should be extending (15.24cm)
      beyond each side of the rough opening jamb or jack
    • The Foam wedge should be against the sub straight,
      sitting parallel with the top of the rough sill plate,
      while the paper skirting (attached to the foam) is
      sparsely stapled to the sub straight and hanging
      down below the sill plate.

Step 4:

  1. Carefully cut down alongside the jack stud
    through the paper and foam, stopping at the corner
    where the jack stud meets the sill plate.
  2. Cut horizontally outward parallel with the rough
    sill through the paper removing only the section of
    foam and paper, leaving the paper skirting hanging
    below the sill out ward 15.24 cm .
  3. Complete this task to both ends of the HomeFlash.
    • Once complete, the paper-covered foam section of
      the HomeFlash should now sit snug between the
      jack studs on top of the rough sill. The membrane
      covered foam surface is sloping from interior to
    • It is important that the foam wedge is snug between
      the jack studs, and the paper skirting component is
      hanging down below the sill and extending outwards
      15.24 cm past both sides of the rough opening.

Step 5:

  1. Flip over the HomeFlash foam saddle from the sill revealing the rough wood sill plate. Coat the HomeFlash sealant over rough sill plate and upward onto the jack studs 15.24 cm (6”) vertical on both jack studs. Completely coating the entire rough sill surface.
  2. Also apply HomeFlash sealant around the outside lower corners onto the sub straight surface a minimum of 15.24 cm (6”) bridging the paper onto the sub straight.
  3. Fold the HomeFlash back over onto the sill, “IMBEDDING” the foam component into the fresh sealant.
  4. Tool the HomeFlash sealant down from the jack stud onto the HomeFlash surface. Additional sealant should be applied ensuring a sound moisture barrier at the inside corner where jack stud meets HomeFlash. A heal bead of sealant may be also applied at both inside corners.
  5. Also imbed the upper edge of the paper that sits against the sub straight, ensuring no moisture can run behind the skirting.
  6. Window setting or shimming blocks can be immediately secured through HomeFlash in locations meeting the window manufacturer’s specifications.

Areas of Caution

  • Do not use two separate pieces of HomeFlash in one rough opening. The HomeFlash must be one continuous piece to ensure integrity.
  • Please ensure that the coverage of the sealant is liberally used to ensure consistent in depth and coverage
  • Please ensure the sealant is liberally applied at the jack stud and rough sill. Enough sealant should be used so that the sealant oozes up between the jack stud and the HomeFlash completely impregnating the HomeFlash within the caulking

*Minimum code requires that building paper must be a least 6 inches past the rough opening.
**HomeFlash can be installed with inside edge flush with the rough sill to 1 inch inside the rough sill to allow room for spray or bat insulation during window installation.