Installing new windows in an old house isn’t a challenging job. If you’ve planned to install new windows by yourself, you must be aware of some important steps. Windows not only differ in style, size, and design but they have different installation methods as well.

Here is an easy step-by-step guide to installing new windows in your old house.

Tools you will need

Before you start replacing your worn-out window, make sure you have all the necessary tools required for window installation.

These include:

  • Measuring tape
  • Caulk gun
  • Hammer
  • Cordless drill/driver
  • Putty knife
  • Spade bit – ⅜-inch
  • Utility knife
  • Flat pry bar
  • Paint scraper

How to install new windows

Once you’ve gathered all the tools necessary for window installation, follow these easy steps to replace your old windows safely and professionally.

Man installing a window

1. Measure the windows

The first and foremost step in window installation is taking accurate measurements of the windows. Before starting with the installation process, make sure you’ve got the right measurements so you can find the perfect fit. Measure the dimensions of your current window frame to ensure you order the right size of the replacement unit.

How to take accurate measurements:

  1. Start by measuring the inside width of your current window frame, jamb to jamb, in three different places – across the top, middle, and bottom.
  2. On a paper, note down the smallest measurement among the three.
  3. Calculate the height of the window from the top of the sill to the underside of the head jamb in three different places – left jamb, middle, and right.
  4. Once again, note down the smallest measurement.
  5. Examine the squareness of the frame by calculating the diagonals from one corner to the other.
  6. Examine the slope of the sill with the help of an angle-measuring tool.

2. Remove the sash

How to remove the sash from the window frame:

  1. Remove the lower sash by prying off or unscrewing the interior wooden stops. If you’re willing to reinstall the stops, make sure you’re doing it carefully as they can easily be broken.
  2. Uninstall the parting beads to release the upper sash. Here, all you need to do is simply press in on the jamb liners and pull the top of the sash forward.
  3. Turn one side of the sash upward to release it from the jamb liners.

3. Pry out the jamb liners

If the frame was previously fitted using vinyl or aluminum jamb liners, pry them free with a flat bar. When working on the original window, take off any wooden stops you see from the frame. Additionally, don’t remove the interior and exterior casings.

4. Set up the frame

Scratch all the loose and blistered paint you see and patch all the cracks and holes using exterior-grade wood putty.

5. Prep for insulation

Consider polyurethane foam for insulation as it is more effective at obstructing the air than fiberglass insulation. Make sure that you only use a low-pressure, minimally expanding foam specifically designed for windows and doors. Anything else will bend the frame and restrict the sash from working properly.

  1. Remove any fiberglass present in the weight pockets.
  2. Bore 3/8-inch-diameter holes, one in the center and others near each end, down across the sill and up through the head jamb.

6. Spray in the foam

How to spray in the foam:

  1. Spray the expanding foam into the holes until you see it oozing out (you can either use a commercial system or a simple can).
  2. Also spray foam into the sash weight pockets present in the side jambs.
  3. Leave the excess for at least 6 hours to harden.
  4. Break or cut it off before you replace the sash-weight pocket panels.

7. Caulk the opening

To install the window, apply an elastomeric caulk on the inner face of the exterior casings or to blind stops you can see at the top and sides of the frame. Furthermore, run two continuous beads of caulk along the windowsill.

8. Install the new window

Work from inside the room and follow these steps:

  1. Set the bottom of the insert replacement over the sill.
  2. Now, tip it up into the opening.
  3. Lastly, press the window against the blind stops or exterior casings.

9. Fasten the window loosely

Once you’re done with installing the new window, hold it in place with a 2-inch screw-driven screw-driven loosely along the upper side jamb and into the frame. Make sure that the screw is in just far enough to let the window operate properly. Finally, close and lock the sash.

10. Wedge as necessary

How to wedge as necessary:

  1. Adjust the window by inserting wedges under the sill and behind the side jambs until it is all set to open, close, and lock smoothly.
  2. Measure the new window diagonally from one corner to the other – all the measurements should be equal. When the window is finally square, set it in place by screwing through the predrilled holes.
  3. To prevent the frame from bending, slip a shim behind the jamb at every screw.
  4. Screw through the shim.
  5. Cut off the shim flush using a utility knife.

11. Caulk, prime, and paint

Follow these simple and easy steps to paint the window your desired color:

  1. From the outside of the room, calculate the gaps present between the window frame and the casing.
  2. Fill these gaps less than ¼ inch wide using elastomeric caulk (wider gaps need to be stuffed with a foam-rubber backer rod first).
  3. From inside the room, fill in the gaps using minimally expanding foam.
  4. Finalize by reinstalling the old stops or adding the new ones.
  5. Lastly, prime and paint to give it an appealing look

Ready to replace your old windows?

Taking accurate measurements and making sure your window fits in perfectly is a challenging task. It is better to hire an expert to get the job done. Our trained and professional workers will install your new windows effectively. Contact us today and get a free quote.

Man installing a window

Leave a comment

Your email address will not be published. Required fields are marked *