There is something special about historic windows that have survived more than a hundred years. Take the double-hung window as an example: It’s amazing that such a simple configuration of wood and glass can perform effectively for so long. As a master craftsman, it’s important to me to build things that last, and double-hung windows have certainly earned their place in history by withstanding the test of time.
Once back in the shop after performing the evaluation and extraction, I’ll strip the windows sash, and jambs so they can be examined for repairs.
It’s helpful to think of these historic window systems as millwork, because that is exactly what they are comprised of. The quality of the wood is very important. Most of these historic windows are made from tight-grain fir, although I have seen historic double-hung windows made from cedar, oak, mahogany, and even cherry. Wood was a significant local commodity back in the day, so places like the La Conner Quilt & Textile Museum had sashes that were made of locally abundant cedar. Historically accurate woods should be used to restore the windows, like vertical tight-grain, fir.
One reason historic sashes last so long is because the joints were made open, without glue or sealers. Historic homes were designed to send moisture down and away from the building, so when repairing historic windows, it’s imperative that you deviate from the modern tendency to use glue or caulk in the joints. Pre-prime all components with a quality oil-based primer before assembly. This gives the wood an added layer of protection.
Replicating new components is accomplished through shop millwork and assembly. We use a numbering system to stay organized, which also keeps each window’s parts grouped together. The millwork must be custom-made, so restoring these windows requires a shop that is equipped to replicate the necessary components. Assembling the window should prove to be a smooth process for sash and jamb alike. The last thing we do is install the glass and apply a quality glazing putty.
I like to take extra care when transporting historic windows. One reason is because of the lead that remains in the paint—I don’t want to leave a chip behind. Historic double-hung windows are also glazed, and the glass is fragile and breakable. To address these concerns, I like to wrap the windows in plastic bags and tape the bags closed. Having an upright transport rack in the back of your vehicle ensures that the sash will be transported securely, without undue stress on the windows.
There is a lot to know and learn about historic windows. A restoration should only be performed by someone who has the talent and the expertise to do the job properly. The historic homes and buildings in our community are emblematic of our heritage, and we all want to see them skillfully preserved.