Window Installation Tips

How to install windows without a professional

Learning how to install windows is a skill that could save you hundreds or even thousands of dollars. The good news is that the basic process is essentially the same whether you're installing bay windows, picture windows, or specialty windows. You'll only need to adjust your approach if your new windows are hinge-operated, or if you're installing storm windows in front of or behind an existing pane of glass.

In most cases, the following list of supplies will suffice: measuring tape, screwdriver, hammer, utility knife, chisel, square, caulk, caulk gun, and window shims.

How to Install Windows

Here's your step-by-step guide to installing windows:

  1. Take accurate measurements of the window's height and width from inside your home. Measure in multiple areas both horizontally and vertically, and use the narrowest value.
  2. Locate the outside stops of the window jambs. Use the caulk gun to place small dabs of caulk at these points.
  3. Install the sill angle of the new window frame.
  4. Place the individual sashes if you're installing a double-hung window.
  5. Caulk along the header to seal off any gap between it and the top jamb.
  6. Place the pane of glass in the new frame(s). Check to make sure they're square; if not, you'll need to shim them into place.
  7. Install the mounting screws to secure the window in place.
  8. Check to make sure each sash moves correctly (if you're installing a double-hung window).
  9. Add caulking along the inside of the window.
  10. Install the window's inside stops.

Remember that manufacturer's instructions will accompany any windows you buy, so you can also refer to them as you go.

Installing Storm Windows and Hinged Windows

For hinged windows (such as casement windows), you'll need 15-pound felt paper in addition to the aforementioned supplies. Begin by taking accurate measurements once again to make sure the window will fit in the frame. However, the overall process differs slightly from there. Here's what you'll do next:

  1. Cut strips of 15-pound felt paper about 2 feet wide. Place them along the top, bottom, and both sides of the window frame.
  2. Slide the window into the opening and center it. You'll need the help of a second person to accomplish this properly.
  3. Level the window across the bottom of the windowsill.
  4. Moving from right to left, plumb and square the window into place.
  5. Install the hinges and screw them into place.
  6. Test the hinges to make sure the window opens properly.

Installing storm windows is a fairly straightforward process, but it requires a different approach. You will also need a power drill in addition to the other supplies listed above. Once you're ready to get started, use this guide to properly install a storm window in an existing frame:

  1. Take accurate measurements along the inside edges of the window frame. Make sure your storm window is ¼ inch shorter than the opening itself.
  2. Place a strip of caulking along the casing where the storm window will rest.
  3. Attach the storm window promptly -- don't give the caulking a chance to dry.
  4. Center the window by making fine adjustments as needed. Use your square to make sure all four corners are properly oriented at 90 degrees.
  5. Starting from the bottom and moving your way up the window, attach the window fins to the casing.
  6. Once you're sure the window is square and properly installed, use a power drill to create small holes near the bottom edge of the window frame. This is done to ensure excess moisture does not become trapped between the primary window pane and the storm window.

Again, refer to your manufacturer's instructions if you have any concerns about the proper installation process. It's a good idea to have a helper along with you, especially if you're just learning how to install windows for the first time.

Installing windows isn't an extremely complicated task, but it's one that must be done with care, precision and patience. Errors can cause drafts, and that can diminish your home's energy efficiency. Be sure to take the time to install the window correctly the first time; you'll see a major difference on your future utility bills.