Integrity Wood Ultrex Certified Mull

Supplemental Instruction

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ABSTRACT: Use these instructions in conjunction with the detailed installation instructions included with each order. This instruction is a guide for placement and application of brackets and additional fastening methods for certified mull products. As always, read all instructions thoroughly before beginning to install your certified mull window or door.

Usage Date: 6/26/2017 to present.

NOTE: Numbers listed in parentheses () are metric equivalents in millimeters rounded to the nearest whole number.

NOTE: Fasteners penetrating chemically treated lumber must be a minimum of 0.90 oz/ft2 zinc dipped galvanized or stainless steel type 304 or 316.


Fasten certified mull products to the rough opening using either mull clips and nailing fin or structural brackets.


These products contain chemicals known to the State of California to cause cancer and birth defects or reproductive harm.

Mull Clip Spacing and Placement

NOTE: Use Certified mull clips in conjunction with nailing fin. The mull clips are different for jambs/head jambs and those used for the sill. Jamb/head jamb clips have a 45 degree bend to fit around the nailing fin. Sill clips have a 90 degree bend.

The following product specific sections will provide more detail on where to install clips at mull points.

Structural Mull Bracket Spacing and Placement

Refer to the Structural Installation Instructionsregarding the placement and unit installation of Certified Mull structural brackets. Refer to the installation instructions provided with the unit for proper installation, shimming, and sealing procedures.

Casement, Awning, Polygon, and Inswing French Door

1. Place mull clips 1 1/2" (38) on either side of each mull point.See Figure 1.

Figure 1
1 1 1/2" (38)

2. Attach the mull clip with eight #8x1 1/4" (32) Phillips flat head screws (casement/awning/polygon) or eight #7x5/8" (16) screws (IIFD). See Figure 2.

Figure 2
1 #8x1 1/4" (32) Phillips flat head screw (ICA/IAWN/IPOLY) or #7x5/8" (16) (IIFD)

Double Hung, Glider, Sliding French Door, and Sliding Patio Door

1. Place mull clips 1 1/2" on either side of each mull point. Use the holes in the clips to mark the fastener locations.See Figure 3.

Figure 3
1 1 1/2" (38)


Doors DO NOT get mull clips attached at the sill.

2. Carefully drill 3/32" (2) pilot holes through the first layer of the Ultrex frame at each hole location marked previously.See Figure 4.

Figure 4

3. Apply two 5/16" x 4" (16x102) beads of construction adhesive on the frame where you will install the clips. Then attach the clip to the frame with eight #7x5/8" Phillips flat head screws. See Figure 5.

Figure 5
1 Construction adhesive
2 Mull bracket
3 #7x5/8" Phillips flat head screws

IRTM over Casement, Awning, and Polygon

1. On lower units, place the mull clips 1 1/2" (38 )on either side of each mull point. Attach with eight #8x1 1/4" Phillips flat head screws.See Figure 6.

Figure 6
1 1 1/2" (38)
2 #8x1 1/4" Phillips flat head screw
3 IRTM window

2. At the roundtop, place three roundtop installation clips at each mull point starting 1 1/2" (38) from the mullion. Attach these with three #7x5/8 Phillips flat head screws. See Figure 7.

Figure 7
1 1 1/2" (38)
2 #7x5/8" Phillips flat head screw
3 RT installation clips
4 IRTM window

Outswing French Door

1. Center an IOFD clip over each mullion. Attach with #7x5/8" Phillips flat head screws through every hole in the clip. See Figure 8

Figure 8
1 IOFD mull clip
2 #7 x5/8" Phillips flat head screws

Installing Windows and Doors that Use Mull Clips

1. Use the screw holes in the mull clip as a guide to drill through the nailing fin with a 1/8"(3) drill bit. This will give you the location of the screw holes when you fasten the unit to the rough opening. See Figure 9.

Figure 9

2. Follow the installation instructions provided with your window or door for proper installation, shimming, and sealing procedures.

3. Once the unit is level, plumb, and square in the opening, fasten through the mull clips/nailing fin and into the framing material with #8 x 1 1/4" (32) screws. See Figure 10.

Figure 10
1 #8x 1 1/4" (32) screws

4. Complete fastening of the nailing fin around the perimeter of the window or door following the recommended spacing and additional steps in the installation instructions.