Installing French Doors With a DIY Transom Window

Right away we made plans to install a pair of French doors. However, we had a dilemma. The existing opening to the den was 8 feet tall. My front door is 8 feet tall as well, but the rest of the doors in my home are the standard 6 ft. x 8 in. height.

The debate was “Should I hang 8 ft. tall doors to fill the space? Or go with shorter doors and match the rest of the house?”

I came up with an option that would give us the best of both worlds. We decided to install off-the-shelf French doors and build a custom transom window to fill the space above.

We headed to The Home Depot and picked up a pair of 60 in. x 80 in. French doors.

The first step we took was to prep the opening for the doors. The French doors we used required a 62 in. rough opening. For us, that meant removing the drywall and moving one of the trim studs.

At that point, we installed and leveled the doors. If you haven’t installed pre-hung doors before, I recommend checking out this tutorial.

I cut a top and bottom plate to run the length of the box, two sides, and two dividers. I connected the top and bottom to the sides, using glue and 16-gauge finish nails.

Next, I divided the interior length by three, giving me three equally sized windows.

Then, I attached the dividers with more glue and finish nails.

To keep the window glass in place, I chose to use ¾ in. quarter-round moulding.

I measured the circumference of each window opening.

Then, I cut and mitered the trim, creating a frame.

I attached the frame to the inside of each opening, ⅛ in. from center, using glue and 18-gauge brads.

With the doors and windows installed, I could add the door casing and decorative trim. I attached a small strip of lattice moulding over the seam between the doors and window, making the two look like one united piece.

Next, I caulked every seam and filled all the nail holes with wood filler. I painted the casing to match the rest of the trim in my home and painted the door and transom, using the color “Raven Black” by Behr, in a satin sheen.

Cutting glass isn’t nearly as scary as it sounds. I cut my own glass for my kitchen remodel, but since the transom is within 24 in. of an active door, residential building code requires the window glass to be tempered. I ordered three pieces of ⅛ in.-thick tempered glass from a local glass company for around $75.

In each window section, I ran a bead of clear silicone caulk on the flat side of the quarter round trim and pressed a sheet of glass firmly in place.

I cut more quarter-round trim for a second set of frames.

Using 18-gauge brads, I very carefully attached the moulding to the transom frame, sandwiching the glass and holding it in place.

Next, I caulked the seams, then painted the quarter-round frame with the same black paint.

The last step was to add the door hardware. To protect the finish on the doors, I made my reference marks on top of a small strip of masking tape.

The hinges included with my set of doors were Satin Nickel, which worked perfectly with the black doors, so I chose Kwikset Milan levers in the same color.

These French doors are a little unusual. They came with a ball catch installed on the top of each door.

That means I didn’t have to worry about drilling out and attaching a lock bolt to hold one side closed. Both doors can be opened or closed independently. More importantly, I could use dummy levers instead of a functioning doorknob.

A dummy lever is fixed in place and doesn’t use a bolt and strike plate. Since the ball catch holds the door closed, I just needed something to grab when I push or pull the door.

I attached a dummy lever on both sides of each door.

Lastly, I screwed the ball catch strike plates to the top jamb, making sure they lined up properly with the bearings in the doors.

And now my den has doors!

I’ll admit, I was super nervous about painting the doors, transom and whole jamb black, but I’m so glad I did! I love the contrast between the dark door and my white walls.

I am so glad the existing opening was 8 feet tall. I absolutely love the added light the transom window brings into the room.

Although it looks intimidating, my transom window was really pretty simple to build. It's basically a box with sheets of glass held in place with quarter-round moulding.