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How to Install Flashing Tape Around Windows: The Correct Sequence

When it comes to creating a reliable weatherproof seal around windows and doors, FrogTape™ Pro Grade Flashing Tape is an ideal solution. Its ShurGRIP® high-performance solventless acrylic adhesive provides a strong, durable bond, while the flexible backing easily conforms to edges, corners and other building transitions. Designed for both residential and commercial applications, FrogTape Pro Grade Flashing Tape helps create a continuous seal that protects against air and water infiltration.

FrogTape Pro Grade Flashing Tape can be used in multiple window and door flashing applications, including installations where the weather-resistive barrier (WRB) is applied either before or after window installation. The example below demonstrates one common installation method when the WRB is applied after window installation. For detailed instructions on all approved installation methods, download the complete installation guide.

Step 1: Prepare the Opening

Make sure the rough opening and surrounding wall surface are clean, dry and smooth. Repair any damaged or unsupported areas before installation.

Step 2: Install Sill Flashing

Cut a piece of flashing tape long enough to extend at least 6 in beyond both sides of the rough opening. For flashing windowsills, tape widths of 6 in, 9 in and 12 in are recommended.

Remove the top portion of the release liner, leaving the lower portion in place for removal later. Apply the exposed adhesive portion of the tape inside the windowsill, with at least a 2” overhang of tape on the exterior side of the opening. Thanks to its advanced solventless acrylic adhesive, FrogTape Pro Grade Flashing Tape can be repositioned as needed before pressure is applied. Once pressure is applied to the tape, the adhesive forms a secure bond that resists movement.

Using a straight edge tool like a credit card, squeegee or your hand, apply firm pressure across the entire windowsill and jamb surfaces of the tape to create a continuous, wrinkle-free seal. Cut the tape at each corner of the overhanging tape and wrap the tape around each jamb and onto the sheathing, using the squeegee to firmly apply pressure over the tape. Remove the liner from the overhanging tape and press the tape down onto the sheathing. Use the squeegee to firmly apply pressure over the tape. Cut 2 additional pieces of tape, approx. 3” x 3” and place 1 piece in each corner, overlapping the sill tape and covering the exposed sheathing.

Step 3: Apply Sealant

Apply sealant around the perimeter of the rough opening or around the outside edge of the window frame according to the window manufacturer's instructions.

Step 4: Install the Window

Place the window into the prepared rough opening and secure it according to the manufacturer's installation requirements.

Step 5: Flash the Window Jambs

Cut two pieces of flashing long enough to extend at least 6 in above and below the rough opening. Remove the release liner and apply the tape along both sides of the window, overlapping the sill flashing at the bottom. Use a squeegee to apply firm pressure across the entire surface of the tape, creating a continuous seal free of wrinkles, creases or trapped air.

Step 6: Flash the Window Header

Cut a piece of flashing tape long enough to extend at least 6 in beyond both sides of the rough opening. Following the same installation process used for the side flashing, apply the tape across the top of the window and firmly press it into place with a straight edge tool to ensure a continuous seal.

Step 7: Integrate the Weather-Resistive Barrier (WRB)

Install the WRB according to the manufacturer's instructions, ensuring it overlaps the window flashing to help direct water away from the opening.

Step 8: Finish the Exterior

Install trim or exterior cladding around the window and seal joints as recommended by the window and cladding manufacturers.

By following these steps, you can create a weather-resistant seal around window openings with FrogTape Pro Grade Flashing Tape. Its fast and easy installation, strong adhesive bond and long-term performance in temperatures ranging from -40 F to 240 F help provide lasting protection against air and water infiltration. For complete installation details and additional approved installation methods, download the full installation guide.

Try FrogTape™ Pro Grade Flashing Tape and see the difference in your insulation needs.

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