How to Replace Vinyl Windows

house with vinyl windows
  • 2-4 hours
  • Intermediate
  • 200-400
What You'll Need
New vinyl window
Tape measure
Small pry bar
Silicone caulk
Caulking gun
Wood shims
Spray insulation

Replacing vinyl windows is a manageable DIY task for most homeowners. Replacing these windows is much easier than regular wood windows, or large casement windows. In fact, specific vinyl replacement windows are made for a simple install. If you are thinking about replacing the vinyl windows in your home with new ones, here are some steps to take for a quick, successful, and air tight install.

Step 1 - Determine Size of New Vinyl Window

Before you buy your new vinyl window you will need to know the dimensions you need. Remove the outer trim of the window that is already installed and measure the height and width of the casing. It is important that you do not remove the window from the casing yet. Once you have the dimensions from the window casing, it will need to be ordered from the home center.

Step 2 - Remove Old Window

man installing a window

Once the new window has been delivered, and it is in good shape (glass is not broken), then you can move onto the actual replacement. Remove the exterior, and the interior trim around the window. You will have to lift the window pane up until you can see the screw hole on the side. If replacing an older window that is nailed, use a reciprocating saw to cut the nail. Slide the blade in between the window frame and the wood casing. Otherwise, use a drill to remove the screws holding the window in place. Remove window from opening.

Step 3 - Clean Window Casing

With the old window out you can now inspect the casing. Check to make sure that the wood that frames in the window casing is still in good condition. If not, you will have to replace some. Scrape away any old caulking and insulation. Remove any broken nails or screws that were broken when removing the window.

Step 4 - Caulk Window Casing

Once the casing is clean, lay a thick bead of silicone caulking around the casement where the window will be placed.

Step 5 - Install, Center, and Level Replacement Window

person caulking a window

Lift up the window into the opening and center it in place. Once it is in the center, place a small level on it to know where the placement of shims should go. Place a screw in the upper right corner and check it for plumb and level. The shims should be driven in around the window until the window is perfect.

Step 6 - Complete Securing Window

The vinyl window will have four different screw holes on the side. Make sure to use three-inch screws and secure the window. Cut off the ends of the shims to make them flush with the window casing.

Step 7 - Insulate Window

Spray some foam insulation around the edges of the window where there is any type of crack. Do not spray too much as the foam will expand and can warp the vinyl window.

Step 8 - Finish With Caulking and Trim

Give the window a better seal by applying a very thin bead of caulking and spreading it out flat. Place the trim boards on both the exterior and interior.