Residential Construction Window Installation Guide *Source: (1) Carpentry & Building Construction Feirer & Feirer (2) Sill to Sash; A Professionals Guide to Windows & Doors

Properly Installed Window Must… Protect the integrity of the window in that the window should not structurally support anything other than its own weight. Have an air tight seal around it. Have an air tight seal around it. Have a continuous and unbroken thermal insulation between frame of the window and the wall. Have some allowance for differential movement between the window and the wall. Be installed in such as way as to must maximize the performance of the energy-efficient features of the window.

Installation Windows are put in after the exterior walls have been sheathed but before wood, vinyl, or metal, siding is installed. If house is covered in house wrap make a horizontal cut just above the height of the window and slip the top flange of the window under the resulting flap.

Installation The first step in installation it to check the squareness of your rough window opening by measuring the diagonals of the opening. The measurements should not differ by more than 1/8” or 3mm. The rough opening measurements must then be checked against the window itself. There should be a ½” gap around all sides of the window to allow for leveling during installation, placement of shims and insulation as well as expansion afterwards.

Installation Windows must be properly aligned along three planes. They must sit square and freely in the rough window opening. Any pressure at any point on the window frame could cause it to be pushed out of square. Secondly the window must be installed level along its horizontal axis. This will ensure no water hangs up in the operating components of the frame and that the window looks in sinc with the other lines of the house. Thirdly the window must be plumb or level from top to bottom. The integrity of the sill slope must be maintained to properly shed water.

Installation 2” cedar shims are used to wedge the window into position ensuring it is square, level, and plumb. The first step is to use shims spaced approximately 16” or 400mm apart on the sill to make it horizontally level. Next level and secure the window vertically placing shims on each side of the frame and rough opening. Shims should be placed near the top and bottom and in the middle with no more than 24” or 600mm between them. In most cases shims should not be used at the head or along the top as normal building movement may affect the operation of the window.

Installation Once the window is secured in place with shims but before the fasteners are installed it should be checked once more for squareness, plumbness, vertical and horizontal levelness and that all moveable parts and locking mechanisms operate freely. Anodized or rust protected screws are the fasteners of choice and should be driven in through the center of every shim or nailing flange if one is supplied. Once again check to see that the window remains square, level, and plumb.

Insulation The gap around the window must be insulated. It is important to use products that will easily fill the gap without creating any stress on the frame of the window. Low expanding polyurethane is well suited for this job because it will expand to fill and not place too much pressure on the frame. It can be trimmed flush both inside and out once it cures. If fibre insulation is used be sure not to pack it too tight as it will loose its effectiveness. Reconfirm the window remains square, level, & plumb and that it operates properly.

Residential Construction Window Installation Guide *Source: (1) Carpentry & Building Construction Feirer & Feirer (2) Sill to Sash; A Professionals Guide to Windows & Doors