Window Prep

Prior to installing windows, rough openings are slashed with flexible tape

The adhesive in pressure-sensitive ZIP System tapes is activated only when pressure is applied over the entire surface, as this worker is doing using a J-roller. 

Modern windows are nearly leakproof, but over time some moisture will make its way through the seals at the glazing or seams in the frame. To prevent moisture damage, best practice is to flash the rough sill and jambs before installing the windows.

The flashing used on the Boardwalk Builders project was ZIP System Stretch Tape, which stretches in any direction, making it an ideal material for wrapping joints between framing and sheathing at rough openings. Acrylic-based Stretch Tape bonds to a variety of materials (including wood, concrete, masonry, metal, glass, and PVC) and can be applied in temperatures as low as 0°F. For this job, the crew used 10-inch-wide Stretch Tape (3- and 6-inch-wide rolls are also available), which covered the 2x6 sills with plenty left over to wrap onto the sheathing.

The first step in the process is to fit the rough sills with a piece of beveled siding, placed feather-edge out to promote drainage [1]. Next, strips were cut from a continuous roll to a length that allowed the tape to span the width of the sill plus run up the jambs at least 6 inches. A team of two, one inside and one outside, worked from the center of the sills out toward the jambs, pressing the tape into place by hand, stretching it onto the sheathing at the corners where the sill meets the jambs, and finally using a flat-edged tool or J-roller to apply pressure to activate the adhesive [2]. The work can be done by a single person, but with wider tapes and a lot of windows, it is often more efficient to use two people.

Beveled siding place feather-edge out on the rough sill promotes drainage of any moisture that seeps behind the window.

A worker aligns the tape parallel to the sill, making sure it covers most of the beveled siding and is centered left-to-right in the opening [2A]. The release paper is split along its length, so the outer half can be left in place until the inner half is in position, but this crew had no trouble when removing all of the paper. Working from the center of the sill toward the jambs, the tape is gently pressed onto the sill and into one corner using fingers and palms, then into the other corner [2B].
Press the tape into both the sill and the jamb at the corners using a flat-edged tool—in this case, the edge of a speed square [2C]. Continue up the jamb, pressing the tape into position [2D].
With the tape firmly pressed onto the sill and jambs, the tape is stretched onto the sheathing, making for a watertight seal at the corners [2E]. The final step is to activate the adhesive by pressing the tape using a J-roller [2F and opening photo].​
East Coast

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