How to Frame a Bay Window

Lead Image
  • 15-30 hours
  • Advanced
  • 1,500-4,000
What You'll Need
Bay window
Saw replacement and framing wood

A bay window is a great way to add the illusion of more space to any room in your home. You will need to find a good spot for the bay window as well as decide what type of window you want. The installation of a bay window is a bit more difficult than installing a standard window. The good news is that many window companies have come up with prefabricated bay windows that will fit the space in your home just right.

Step 1 – Correct the Existing Frame

First you will need to locate any problems with the existing window frame. Take out any dry rot areas and replace with new wood. You will also need to make certain that the frame is level. Use new wood to make any adjustments and ensure that the wood is securely attached.

Step 2 – Prepare the Area

Once you have chosen a spot for the bay window to go, get the measurements and get an outline drawn on the outside of the home. This will help you to get more accurate cuts.

Step 3 – Installation

Be sure that you have a very level and stable surface for the frame of the window to rest on. This part is best done with the help of an assistant. Together, you will need to lift the window to the opening. To help the window to stay level, insert shims. While ensuring the levelness of the window, begin to insert screws. In order to attach the roof frame, nail it securely in place.

Step 4 – Framing the Window Cap

The window cap is what will make the bay window look as if it has always belonged in the space. It is framed to match the dimensions of the bay window as well as connect the frame to the home. It leans at about a 45-degree angle in order to accomplish this.

Framing the entire bay window is not necessary. You also can have it made to your specifications so that you can have an easy and quick installation.

Step 5 – Insulate and Weatherproof the Frame

Once the window is in securely, you will need to put in insulation in between the top of the bay window and the roof. You will also need to do this along the bottom and sides. A skirt bottom will also help to seal in the bottom of the window. Finish up with sealing the edges with a silicone caulking that is outdoor grade.

Use insulation tape to weatherproof where the frame and the window will meet. It is a metal tape that has aluminum on one side and a rubber backing. This seals out any moisture that may want to enter the house through these crevices. The tape will help to prevent problems with dry rot as well. This will expand the life of your window.