Make Your Own Storm Windows

By Ed Kearney

Three years ago I decided I had to do something about the low thermal efficiency of our home and the ever-increasing fuel bills. Taking a close look at the windows, I realized they were the cold spots. By putting my hand against the wall just below the window sill, I could feel a down draft of cold air.

I had heard a lot about thermo-pane windows, but I decided there must be an easier and less expensive way than replacing the existing single-pane windows.

I planned a plastic-covered frame that would fit into the window casing inside the house. This frame would be surrounded with foam rubber, which would both form a seal and hold the frame in place: easy to put up, easy to take down.

I purchased enough ten-mill clear plastic to cover my windows, one quart of stain, two six-foot sheets of one-inch by thirty-inch foam rubber padding, and two quarts of contact cement. I already had enough pine-board strips to make the frames. (Since then I have discovered that an ideal wood size can be obtained by cutting two-by-fours into one-inch strips.) Then I constructed the frames, leaving a clearance of about 5/8 to 3/4 inch all the way around them for the one-inch thickness of foam rubber which was to be cemented to the outside edges. This actually made the overall dimensions of the frame 1 1/4–1 1/2 inches smaller than the dimensions of the opening into which it was to fit.

I glued and doweled the frames together, later finding that I could have substituted corner pieces for dowels, saving a little time and expense. For the larger windows, I placed a vertical brace made of the same size material into the center of the frame to give it extra strength. Next, I stained the frames, except for the outside edges where the foam rubber was to be glued. I then placed them on a table, carefully stretched the plastic over them, and stapled it down. It takes a little practice to stretch the plastic evenly into place, leaving no “waves”; some restapling may be necessary now and then. Next I cut the foam rubber into strips and cemented the strips to the outside perimeter of the frames.

I then cut more wood strips, stained them, and nailed them to the frame over the plastic. This not only secured the plastic to the frame, but I found I could staple another plastic sheet to those strips, nail on another set of strips over that, and have a double thermal barrier. My daughter appreciated that in her room. (See picture 1.)

For some windows—especially bathroom, laundry, or kitchen—ventilation may be desirable: This is possible by inserting within the frame two horizontal wood strips about six inches apart, into which another frame is set. This smaller inset frame is connected to the lower horizontal wood insert by a simple hinge—a strip of denim or light canvas, glued the full width of the horizontal strip. (See picture 2.) I screwed a simple wood latch to the top horizontal strip and a wood stop on each top corner of the ventilating frame. We open the ventilating frame, letting it hang down, and reach in to open the main window. This allows only a small opening, but on a cold winter day it is quite sufficient.

At the top of each storm window I write the room into which it will go. On each plastic pane I stick a small “Do not touch” sign because the plastic might stretch from too much pressure. (I have to admit, though, that this brings about the same response as a “wet paint” sign.)

Touching the plastic should also be avoided because cleaning off finger marks is a delicate job.

Installing the storm windows is easy. Push them in first at the top, and then, with one continuous motion, push up and in at the bottom. That’s all. The foam rubber makes an airtight seal, and it compresses enough to make room for the fingers, whether inserting or removing the window.

Before storing them, I drive a two-inch nail through the foam rubber and slightly into the wood at each end of the bottom of the frame. The nails support the frame, keeping the weight off the foam rubber so that it will not compress during storage and lose its resiliency. Then I lean the frames against the basement wall with a piece of plywood in front of them for protection. I also drape a sheet over the top to protect them from dust. (The nails are easily removed before mounting the storm windows.)

Our patio has a thermo-pane door, but since a lot of heat is lost through its aluminum frame, I am in the process of building a wooden frame for it also. Since there is no window casing around the existing frame into which to press my wooden frame, I will cement the foam rubber to the bottom of my frame so that it will seal against the floor, and then to the three faces of the frame that will seal against the existing door trim. Then I will screw my frame to the trim; with care and a light touch the screws can be replaced in the same holes year after year. I’ll cover the lower three feet of the door frame with plywood, since plastic too close to the floor would be easily damaged by routine housecleaning or children at play. (See picture 3.)

These storm windows are easy to make, efficient, and economical. Since they are installed on the inside of the house, they do not become weather beaten and should last indefinitely. Besides conserving energy, they have also made our home more comfortable by maintaining a more even heat.

Illustrated by Ron Boldt

Picture 1. I was able to create a double thermal barrier by adding another sheet of plastic and another set of wood strips to the basic window.

Picture 2. In windows where I need ventilation I installed a small frame within the storm window, hinged with light canvas. When we open the small frame we can also reach through it and open the main window.

Picture 3. For doors with no recess to fit the frame into, such as a patio door, I cemented foam rubber to the bottom of the frame and to the three faces of the frame that fit against the trim. When I screw the frame into place a seal is formed that keeps cold air out. Then I cover the bottom portion of the frame with plywood, to keep children’s feet or other objects from going through the plastic.