Custom Transom for Interior Door

A client of mine wanted to add French doors to divide a large bonus room upstairs in his home. It's the same room where we installed the laminate flooring a few weeks ago. (See this post.)

Anyway, he ordered the doors to be custom made to fit this opening.  The only problem was, there was still a 7 inch gap at the top.  Instead of covering this with drywall or trim, he wanted me to build a transom or window over the door to coordinate with the French doors below.

I measured the door frame below and wanted to match this size with the transom above.  I bought some 1/8th inch window glass and made the frames out of 1x6 boards that I had to rip to 4 1/2 inches.  To strengthen the corners I made mortise joints in the horizontal pieces that the sides would fit into.  You can see the notches in the picture.

The glass would be set toward the back, around 3/4" from the edge to match the French doors.  Thinking ahead, I realized that if I put this all together I would not be able to get my nail gun inside the frame to nail the muntins in place. ( A muntin is the strip of wood trim that will hold the window in place.) So, I glued & nailed the top and bottom muntins before I assembled the frame.  You can see in the first picture that the muntin is already in place.

I clamped the frame together on a flat surface with a little glue and held it together with a couple clamps while a put some nails in the corners.  The clamps enabled me to square it up perfectly before I nailed it.  It needs to be square so that the window will fit right.

Now that the frame was finished I inserted the glass over the muntins I already installed and added the muntins on the other side.  This would 'sandwich' the glass in place.

WHERE DID I GET MUNTINS?   

This took a little improvisation.  I ended up buying some pieces of mullion trim that are widely available and 1 1/4" wide.  (Mullion is trim that separates different windows, whereas muntins separate panes of glass, at least that's how I understand it...)  I ripped about 3/8" off of each edge to use as the muntins.  This worked great for this project because the edge profile was a very close match for the muntins used for the doors and sidelight.

Once the transoms were completely built I positioned them in place above the door and tacked them in place with some finish nails.  All that was left was add normal door casing.

It was a beautiful day and this was a fun project.  Kind of like craft day at school, except with nail guns...

-Peter

www.CarpentryGuy.com