This story shows you how to install new storm windows.
A high-quality storm window can seal out cold air better than a replacement window for a much lower cost. You can install one yourself in far less time than it takes to install a window.
Unfortunately many storm windows are poorly made, with flimsy corners, weatherstripping that doesn't seal well to begin with and soon gets worse, and small parts that easily break. You'll save money in the long run and prevent hassles if you spend more to buy a quality storm.
A standard storm for a double-hung window is triple-track, meaning it holds two glass sashes and one screen, each of which travels on a separate track. If you like to keep the window open in the summer, you can buy a second screen sash to replace the top glass sash.
A storm window is only as good as its installation. The unit must be installed square or the sashes will not slide smoothly. And it must be tightly sealed against the house with caulking and screws.
Once the unit is purchased, about an hour to install a storm window
Framing square, tape measure, drill, paint scraper, caulk gun, hammer, screwdriver, tin snips
Measuring and checking for square, applying caulk, driving screws
Choose a quality storm window and order one to fit your opening. Use a stable ladder and protect any plantings below.
Caulk, wood or decking screws (or the screws that come with the storm window)
Remove the old storm window or any other hardware that can get in the way of the new storm. To check the window opening for square, first hold a framing square at the corners, then measure the diagonals. If the opening is out of square by more than 3/8 inch, you might be able to adjust the molding to make it square. Otherwise order a storm window that will fit into a smaller opening with square corners.
Measure the horizontal dimension at the top, middle, and bottom of the window, and use the smallest measurement. Also measure the verticals at three points.
If you are installing inside the casing and the stop on the window is narrower than the flange, you can remove the casing or pry it loose so the flange will be behind it. If that is not feasible, cut the flange as necessary, using tin snips.