DIY: Securing Anderson Windows

Set the window into the prepared opening from the outside of the house. Hammer a 2-inch roofing nail through the hole in the nailing flange and into the wall. Insert one nail in each corner from the outside of the house to secure the window in place.

Close the window and lock the sash in place. Insert three equally spaced shims up both sides of the window on the inside of the house. Run a tape measure from one corner of the window to the other on both sides to make sure the measurements are the same.

Place a level running vertically on each side of the window and horizontally across the window sill at the bottom to make sure the window is square and plumb. Add and remove shims as necessary until the window is level in the opening.

Hammer in the rest of the nails through the nailing fin and into the wall from the outside of the house. Space out the nails every 6 inches around the entire perimeter of the window. Seal the top and sides of the window with silicone sealant. Run a bead of sealant between the frame and the jamb on the outside of the window to seal the opening.

Cut off the excess shims on the inside of the house with a utility knife. Spray low-expanding foam on the inside of the house underneath the window, along the sill. Spray up each side of the window and along the top to secure the window in place. Cover all gaps between the window and the framing of the house.