How to Install a Window With No Windowsill
- 1). Measure the opening for the width and height, taking the readings from the inner edges of the frame. Move the sashes of the existing window up or down as needed to get at the sides. Order your replacement window unit based on those readings. Leave the existing windows in place until the new unit arrives.
- 2). Pry the trim off the inner edge of the opening with your pry bar and hammer. Keep the trim intact as you remove it. Set it aside. Pull out the sashes, clearing the opening.
- 3). Set the replacement window unit in the opening, bottom first. Push the top up and in until it comes to rest against the trim border that's around the outside edge of the opening.
- 4). Set a level on the unit and shim it around the sides and bottom until it's level. Set it in place with mounting screws, driving them through the screw holes on the inner sides of the unit and into the surrounding frame.
- 5). Tuck fiberglass insulation into the space around the perimeter of the window unit.
- 6). Re-install the trim around the perimeter of the unit, using your hammer and finishing nails. The trim will cover the spaces between the unit and the frame.
- 7). Caulk around the trim where it meets the window and the frame.
