How To Install A Storm Window

When your new storm windows arrive, you will probably start wondering about what comes next. How do you install a storm window so that it works well and looks great? Although it is not difficult to achieve a professional fit, there are a few simple guidelines to keep in mind during the installation process.

Basically, your storm window frames must be hung square with the existing windows and sealed to the opening. All the steps in the installation process are organized to achieve these two requirements. And there is one additional issue – moisture.

Exterior-mounted storm windows will be manufactured with small openings called, 'weep holes” that allow moisture to drain. These tiny holes detract very little from the efficiency of storm windows, and they are absolutely necessary to deal with condensation created whenever there is a big difference in temperature on either side of a window.


In order to achieve a perfect fit for your new storm windows, you simply keep in mind that they need to fit squarely to the existing window frame when they are screwed into it, and they need to be sealed in place with caulk. The only area along the edge of a storm window that should never be sealed with caulking is where the “weep holes” are found along the bottom edge of the frame. It is just as important to avoid caulking these drainage holes as it is to carefully caulk all the other storm window edges.

Assuming your window measurements were accurate when you ordered your custom storms, installing them should prove quite easy. Keeping the above guidelines in mind, you simply screw each storm window into the window stop or into the window trim, depending on your choice of installation method. You will have already made this decision at the time you measured and ordered your new storm windows.

The difference between blind stop (inside mount) and overlap (outside mount) can best be explained by picturing a window shade that fits inside your window frame, compared to a curtain that hangs over the window frame. Storm windows that were ordered to fit inside the window frame are screwed into the window stop, which is the narrow strip that holds the window sash into position within the window frame. Storm windows that were ordered to fit on the outside of the window frame are screwed into the window trim.

Since most storm windows are mounted on the outside of the house, facing the weather and affecting the appearance of the home, installing them properly is important for a number of reasons. Cost of installation is just one of the reasons many homeowners choose to buy storm windows they will install themselves. Besides their anticipated savings in heating and cooling costs, homeowners can expect to save money on installation costs as well.

Professional installers often charge $175 or more to install each window, a cost which represents more than twice as much as the price of an average custom storm window. It is important to remember that old storm windows may need to be removed prior to installation, window frames may need repair and construction debris will need to be removed to a proper trash receptacle. Do-it-yourself homeowners must schedule their time and organize their tools, which can easily be accomplished before their shipment of storm windows arrives.

Knowing how to install storm a window is a skill that is quickly learned on the job, taking time with the first one and following instructions carefully. In the end, a storm window is only as effective as its installation. For the most energy savings, noise reduction and dust elimination, each storm window must be screwed onto the existing window frame, and it must be sealed completely around the edges, with the exception of the weep holes located on the bottom edge.