Guide to Determine Number of Clips 1.No. of clips per side = P x W x H 2. Most windows are rectangles. For example an individual double hung unit with the frame size of 36” W x 60” H. Assume the example project site requires 40 psf wind pressure. No. of clips = (P x W x H)(.0001)/4 figures to be (40psf x 36” x 60”)(.0001)/4 = 2.16 clips 3. Round up to the next higher number, thus budget 3 clips equally spaced along each long side. 4. Calculate the spacing between clips along each long side. Select a distance from corner of no less than 8” and not greater than 24”. 5. Attach clips to short sides (head and sill) at about the same spacing. In this example use 2 clips on the head and 2 clips on the sill. If in doubt reduce the number of clips so that they are not closer than 8” from corner. Thus, 3+3+1+1 = 8 clips total. 6. For Curved or angled units, substitute a rectangle of the same overall width and height. Attach clips at the calculated on center spacing to the curved and straight sides. 7. Double hung units are often tested and rated without clips along the sill because the sill is sloped. If the sill is determined to need a clip and it is sloped, a wood wedge may be glued to the underside to attach the clip to the window. 8. For assemblies of several individual units mulled together, calculate clips and spacing for each individ- ual unit and attach clips to the available outside perimeter sides. At the end of mulls, additional fas- tening might be required. Confirm with project engi- neer or architect/engineer or manufacturer. Fastening Clips Clips may be attached to the window unit either being rotated into place within a groove designed to accept the clip (uPVC) or screwed into the frame (wood). The clip, depending on the length may be face anchored to the rough opening one #8 x 1-1/14” Sheet Metal Screws screw into face of wood buck. If the clip is longer so it projects out beyond the wood buck or rough open- ing, then it can be bent to be flush with the interior surface of the buck or rough opening. Use two #8 x 1-3/4” Flat Head Sheet Metal Screws. Face Mount Hammer Bend 1. Insert Slow Expansion foam tape between the window and the old opening with sufficient room to allow expansion and conformity to the irregularities of the opening. 2.Sealant may not be required. 1. Insert Closed Cell Foam Backer Rod into space around the window leaving 1/4” space between backer rod and exterior face of the window 2. Apply bead of ASTM-C-920 compliant sealant around the entire perimeter 3. Tool and shape and clean excess sealant. Window Fitters Guide to Window Installation 84 ©2022 AWDI, LLC Do not reproduce without permission SAMPLE MANUAL
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