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How to Install Storm Windows

You can improve your home's energy efficiency -- even if you're on a budget -- by installing storm windows. Here's what to do to install aluminum triple-track storm windows to the exterior of your home:

  1. Determine your window casing style "Western" window casings have a blind stop recessed 5/8 of an inch (1.6 centimeters) into the window opening. "Eastern" casings have no such stop [source: Baker].
  2. Measure Measure the horizontal distance between the inside edges of the window casing, and the distance from the bottom of the outside edge of the head casing to the sill [source: Baker].
  3. Size up the new storm windows If you have a "Western" style window casing, you need a storm window that's ¼-inch (6.3-millimeters) shorter and narrower than the casing opening. For an "Eastern" style casing, the storm window should be at least 1 ¼-inches (3-centimeters) wider and 5/8-inch (1.6-centimeters) taller than the casing measurements [source: Baker].
  4. Weatherproof Apply a thick strip of butyl or elastomeric caulk where the storm window will contact the casing. Attach the storm window before the caulk dries [source: Baker].
  5. Center the storm window Rest the bottom edge of your storm window on the windowsill, then square it up to the window casing. This will be easier for a "Western" style casing. When working with an "Eastern" one, you'll have to be careful that the fins on each side of the storm window overlap the window casing equally. Drive a screw into the middle hole of the top fin [source: Baker].
  6. Attach the fins to the casing Start with the bottom of each side fin and work your way up, driving screws into all the holes around the edge of the storm window. Make sure to keep the storm window straight and square [source: Baker].
  7. Check your work Test the sliding storm and screen panes to make sure they open smoothly [source: Baker].
  8. Make "weep holes" Exterior storm windows need small holes at the bottom of their frame to allow moisture to seep out from between the primary window and storm window [source: US Department of Energy].