• Window Sill Opening must be free of dirt, dust, water, etc.
• Dry Wall must be cut level to bottom of window frame

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• Measure Window opening length
• Take measurement at rear and front of opening
• Cut windowsill to smaller of two measurements.
• Option: If tabs/ears are selected add 1 ½” to each side of the sill. (3) Inches more than the window opening

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• To obtain same reveal on both sides of windowsill, measure from window to corner bead on each side (Add amount of reveal/overhang desired to this measurement).
• If measurements on both sides are the same, rip sill accordingly.
• If return depths are different on each side, scribe cutting is recommended (This involves marking to measures on the sill, and marking a line to cut on as a guide).
• (Ripping sill may not be needed if sill tucks under window frame)

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Butting against window frame, on concrete block, pre-cast or wood

• If the windowsill is to be set against the window frame, use plastic shims where needed to make level.
• Be sure that the windowsill is level before using adhesive.
• Once the windowsill is level add adhesive / Titebond Interior/Exterior construction adhesive to substrate.
• Set windowsill, check to make sure the windowsill is still level.
• Some installations may require a cleat under the lip of the windowsill until adhesive is set.
• Adhesive usually dries within 24-48 hours

Tucking under frame, on concrete block or pre-cast only

• Run a bead of adhesive onto concrete block.
• Run a bead of adhesive on the underside of windowsill.
• Tuck back of windowsill under the window frame.
• Tap front of sill down until level, keeping back of sill against frame.
• Clean any adhesive that may have come out from under front edge of sill.
• Check windowsill for final level.
• Let dry for 24-48 hours.

Tucking under window on wood framing

• Place stacks of shims until sill is raised up to window frame.
• Put adhesive over top of shims making sure adhesive also is on wood framing.
• Place sill back in opening and then level front to back with cleat if needed.

Do not remove blue protective tape for at least 4 days for all adhesives to cure properly

1. Adhesive recommended – Titebond Interior/Exterior construction adhesive

2. CRL – Shim stack Shims CAT. # KRS16 – 1-800-262-3299

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