Adding Mullions To Old Windows

When my house was built in 1859, it was common for windows to be made up of small panes of glass. Dividing these separate panes were wood mullions.

Today the look these mullions is commonly provided by adding a decorative mullion over one single pane of glass.

At some point, probably around the turn of the 20th century, the folks who lived here decided to update the front windows by taking out the six small panes in each sash and adding one large pane.

Luckily they didn't update the entire house. The all but two of the windows on the other sides contain the original mullions.

In the front, the windows weren't replaced, rather the mullions cut out to accommodate the larger panes of glass. To regain the original look in the front, I was faced with putting in replacement windows with decorative mullions, finding old windows that were the same size and replacing the original windows with those or having the mullions put back in the existing windows. Each of these options would have involved significant expense.

Instead, after talking with a helpful person in the window department at Home Depot, I decided to see if it would be possible to create decorative mullions. I purchased thirty-two 36" pieces of wood that is about 1/4 inch square, slightly smaller than the width of the existing mullions. Since they would all be on the same side of the building I figured matching the width wasn't essential. I cut each piece to fit inside the sash and then cut a notch in each piece where they crossed.

I did this entirely with hand tools. A hand saw cut the sides of the notch and a razor blade slice was all that was needed to remove the notched piece.

Learning by trial, I improved the construction as I went along by making each notch slightly smaller to provide a more firm fit. At first decided to hold them together with glue, but then decided to add a small staple where they crossed. The final step was to give them a coat of spray paint. The pieces, where I succeeded, were cut just the right size to fit snug inside the sash so they didn't need to by physically attached to the window and can be removed for cleaning.

I have completed two windows on the first floor. I have three upstairs windows, and five in a rental house to go.

The result is satisfying and accomplishes several goals. First, it provides the desired look and looks historically accurate passing at least at first-glance. Second, it saves the original windows. Third--and many people who redo old houses don't think about this, it leaves a story--the large panes of glass became less expensive and so the small panes and mullions were removed (you can see where the mullions had been cut out). Later, other folks came in and wanted to give the house its original look.

Making old houses completely new might sell them, but it doesn't leave much for history. restoring them completely doesn't leave much for history either.