Installation instructions for new construction windows
Installation from interior using mounting straps
NOTE:
These installation instructions require that some type of weather resistant liquid applied or peel and stick waterproofing membrane has been installed inside of the window openings (minimum 4" deep into the opening and at least 3" around the perimeter on the exterior face of walls prior to the installation of the windows). Installation of waterproofing in the window openings should be done by waterproofing contractor. Installation directly against the sheathing is not recommended. Additional materials needed to complete the installation are: silicone caulking, 6” wide (minimum) membrane water barrier tape, shimming material (horse shoe shims preferred), 1 1/2" galvanized or stainless steel screws for installation.
Construction of the Opening
New construction window openings must be square, plumb, level,
using materials that are free of warps, twists, etc. Check opening for
squareness by measuring the diagonals as shown to the right. The
opening is square if the measurements are the same. The opening
should be 3/4" larger than the tip to tip window frame size to allow
for any necessary shimming.
IMPORTANT – be sure the construction of the opening meets all
applicable building codes and standards.
Preparation of the Opening and window installation
1. Ensure that the window opening is built correctly, square, plumb, level and correct size. Size of the opening should be exact size of the window from tip to tip plus additional 3/4" on the width and height (done by carpenters)
2. Apply waterproofing at minimum 4" deep from exterior face of wall and at minimum 3" around the perimeter of the opening at the face of the window. (Done by waterproofing contractor)
3. Insert window into the window opening from interior of the building using manual suction cups and man power or using automatic window lifter.
4. Make sure that window is inserted in to the opening at the correct depth, plumb and level and centered in the opening.
5. Shim as needed according to the shimming diagram, minimum of 1/4" shim at the bottom of the window
6. Using 1 1/2" galvanized self drilling screws fasten the window at the interior to the window opening using mounting straps that are pre-installed on the window perimeter. Minimum of 1 screw per mounting strap. Fasten through all straps around the perimeter of the window.
7. Insert 1/2" - 5/8" backer rod at the interior perimeter of the window against waterproofing and seal entire perimeter of the window
8. Install interior secondary waterproofing silicone sealant around the entire perimeter of the window. Ensure to use silicone sealant that is compatible with waterproofing barrier. Ensure that the silicone joint is properly tooled and finished according to silicone sealant manufacturers recommendations
9. When access to the exterior of the window is possible insert 1/2" - 5/8" backer rod at the exterior perimeter of the window
10. Install exterior primary waterproofing silicone sealant around the entire perimeter of the window. Ensure to use silicone sealant that is compatible with waterproofing barrier. Ensure that the silicone joint is properly tooled and finished according to silicone sealant manufacturers recommendations
11. Install stainless steel drip edge above the head of the window. Make sure that the drip edge is installed 3" past the jamb of the window on each side and that the drip edge is sealed to the waterproofing of the exterior wall using sealants that are compatible with waterproofing barrier used for waterproofing of the building.
12. Finish installation of exterior finishes around the window
13. Install backer rod and finish silicone sealant around the entire perimeter of the window frame. Provide water weep holes at the head of the window above stainless steel drip edge to allow water to escape from behind the exterior finish wall cavity. Ensure to use silicone sealant that is compatible with exterior wall finish and is designed for UV exposure. Ensure that the silicone joint is properly tooled and finished according to silicone sealant manufacturers recommendations.
Mounting strap installation FAQ
How much larger should the rough opening be?
The opening should be the tip-to-tip size of the window plus 3/4 inch on the width and the height, to allow for shimming.
What has to be done before the window goes in?
A liquid-applied or peel-and-stick waterproofing membrane must line the opening at least 4 inches deep and at least 3 inches around the perimeter on the exterior face of the wall. A waterproofing contractor should install it. Do not install directly against the sheathing.
How many screws go into each strap?
At least one 1 1/2-inch galvanized self-drilling screw per mounting strap, through all straps around the perimeter of the window.
How much shim goes under the window?
At least 1/4 inch at the bottom of the window. Shim the rest according to the shimming diagram.
Do I need a drip edge?
Yes. Install a stainless steel drip edge above the head of the window, extending 3 inches past the jamb on each side and sealed to the wall waterproofing. Leave weep holes above it so water can escape from behind the exterior finish.
Mounting straps or nailing flange?
Mounting straps are for installation from the inside into an opening lined with a waterproofing membrane. For installation from the outside into a wall with house wrap, use a nailing flange.
Our windows come with a nailing flange or mounting straps for U.S. construction. Need help with your project? Get a quote or see how we work with builders and contractors.
