Historic Windows: Patience and Persistence Pays Off

There are numerous window companies today who are eager to replace those old windows in your home. After World War II, the double hung, rope and pulley window became a thing of the past. The simple old system of counter-weighting with cast iron weights was replaced with spring suspension systems. Today, modern windows do not use weights, and they are made of a variety of materials including wood, vinyl, and aluminum. Unfortunately, many of these modern windows simply do not have the lifespan of the traditional wooden window. Let's face it, windows that last forever are bad for business.

Our ancestors used their windows much more than we do today. The purpose of a double hung window was to help with ventilation. The top sash could be lowered, allowing the hot air to leave the house, while the bottom sash was raised to allow the cool air in. Modern heating and air changed all of that, and so we use our windows primarily in the spring and fall during those short periods of time when we are not concerned about our pocketbooks.

Now we could debate about energy efficiency, but that is not the purpose of this blog. Suffice it to say that windows only account for about 10% of heat loss, and there are ways you can reduce this percentage through weatherization.

The double hung, rope and pulley window is a very simple thing; two cast iron weights total the exact weight of the window sash allowing the user to open the window without having it come crashing down. Repairs require knowledge of how the window works, and most materials are available at your local hardware store. These windows were made so that any relatively skilled craftsman could repair them.

Removing the historic windows from an older home can drastically change the overall appearance of the structure. Windows are important architectural components, and nothing looks worse than having a modern vinyl window stuck in the middle of a wooden, clapboard home. Even a modern, crisp window pane looks odd when it is seen next to an historic piece of glass. Consistency is just as important as preservation.

The Hazen Historical Museum Foundation has been working on restoring our windows for a few years now. With the help of local craftsman Barry Gregory, we tare taking the time to restore the windows in our historic structures. The windows in Winstead Cottage (circa. 1881) at Bethel Cemetery was our first main project, and we restored the last of those windows towards the end of last year. The National Park Service has a great technical guide about starting the process.

Window repair at Mabry-Hazen House (circa 1858) is ongoing. We started with the windows that were in the most critical condition. Our first step was to build a steam box to speed up the process and to avoid breaking the original glass. Windows are steamed for about an hour, which loosens the old, rock-hard glazing that holds the glass in the window. Any loose paint is also removed in the process. Next, the old paint is stripped completely from the window. Heat guns are used to take the window back down to bare wood.

After all weak areas are identified, an Abatron epoxy is used to fill in any rotten areas. Wood hardeners are also used if any areas appear spongy. If window muntins (the pieces that hold the glass in) are too far beyond repair, we have a blade manufactured to recreate the profile and new muntins are made and installed. Once the window is structurally sound, it is primed before installing the glass. The glass is cleaned and installed with pins and traditional glazing. After it has cured for a few weeks, it is then ready for the final coat of paint.

The only material that is not easy to come by is period wavy glass. We sometimes have to replace a few panes if they are cracked or if they were previously replaced with new modern glass. Obtaining historic glass can be a bit of a quest. Sometimes you can find local architectural salvage in order to obtain period glass. There are modern companies that make reproduction wavy glass, such as Bendheim, but it can become costly. We were fortunate to obtain glass from our local historic preservation group, Knox Heritage. The replacement glass we are using now came out of a home that was built in the 1840's. Unfortunately, the home does not survive today, but we benefit from having period glass to use when replacing modern or broken window panes at Mabry-Hazen House. It is probably as close to local period glass that we will ever find.

Restoring historic windows takes patience, but it is not rocket science. With the right materials and persistence, period windows can be both beautiful and function. Should you be more interested in the process, feel free to contact our staff for additional details. In addition, if you would like to assist us in our window preservation goals, please consider becoming member or making a donation to the project.