Instructions / Assembly

Here is a basic, step-by-step guide to installing a nail ﬁn type, new construction

window, including recommended ﬂashing details often used in the industry.

Rough Opening (REQUIRED)

(Before beginning, always review the instructions supplied with the window.)

Check the Rough Opening:

• The Rough Opening should be level, plumb, and square, and should be properly sized to

receive the window being installed.

• The framing must be substantial enough to properly support the structure around it.

NOTE: For open-stud installation: Before the window can be installed, wall framing must be

covered by backing support material suitable for your region. Mount the window with the

nail ﬁn ﬂush against the applied backing support material. Completely surround the rough

opening with the backing support material as applicable by local requirements. Be sure

backing support is applied prior to weather-resistant barrier.

STEP 1:

Weather Resistant Barrier, (WRB) Wall Preparation (RECOMMENDED)

At the Rough Opening (RO):

1. Ensure that the weather resistant barrier (WRB) is properly and securely fastened to the

exterior wall surface and is free of wrinkles, cuts and tears with adequate overlaps as

described by the WRB manufacturer.

2. Following the WRB manufacturer’s instructions, begin cutting out the RO as instructed.

3. Cut and remove any excess material as necessary or directed by the WRB manufacturer.

4. Cut two 45-degree slits as described, (based on the width of the ﬂashing products

used), from the top corners of the rough opening at the header, to create a ﬂap above

the rough opening. Fold it up and temporarily secure this ﬂap over the opening.

STEP 2:

Wider than

Window Width

Taller than

Window Height

Sill Pan Flashing (RECOMMENDED)

1. Most manufacturers require you to measure and cut a portion of ﬂashing membrane

that is a least 12” longer than the width of the RO sill. This ﬂashing will be used as a sill

pan ﬂashing.

2. Remove a portion of the release paper along the horizontal portion of the sill. Do Not

remove all release paper at this time to prevent over-stretching the ﬂashing membrane

or allowing it to stick to itself and rendering it unusable.

STEP 3:

NEW CONSTRUCTION

WINDOW INSTALLATION INSTRUCTIONS