Installing French Doors with a DIY Transom Window

Article Posted By: Elisha Albretsen

of Pneumatic Addict

Installing French Doors with a DIY Transom

Installing a pair of pre-hung French doors and a DIY transom completely transformed not just one, but two rooms in Elisha Albretsen’s home.

Elisha, who writes the blog Pneumatic Addict, is a fearless DIYer, and shows us exactly how she and her husband completed this project.

Installing the French Doors

We sold our home last year and started house hunting. We were looking for a 4-bedroom home, but when we came across a “3-bedroom plus den” with the perfect floor plan in the perfect location, we changed our minds and rolled up our sleeves.

Our “den” was just a small room, open directly into the living room. I have plans to turn this space into a playroom for my boys, but in the meantime it was no man’s land and a landing place for random junk. Not a pretty view for our guests.

Installing French Doors with a DIY Transom

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?”

Installing French Doors with a DIY Transom

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.

Pre-hung French doors at The Home Depot

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.

Installing French Doors with a DIY Transom

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

Building the Transom Window

With the doors in place, I started building the transom window.

I used 4-9/16 in. wide door jamb stock, which I found in the moulding aisle. To determine the size the window needed to be, I measured the rough opening above the doors.

I purposely made the window ¼ in. smaller, both in width and height so I could use shims and make sure it was level and plumb.

Installing French Doors with a DIY Transom

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.

Installing French Doors with a DIY Transom

Installing French Doors with a DIY Transom

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.

Installing French Doors with a DIY Transom

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

Installing French Doors with a DIY Transom

Installing the Transom Window

At this point, the transom was ready to install above the doors. I slid the window in the opening, shimmed it in place and secured it with more 16-gauge nails.

Installing French Doors with a DIY Transom

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.

Installing French Doors with a DIY Transom

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.

Installing French Doors with a DIY Transom

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

Installing French Doors with a DIY Transom

Adding the Door Hardware

Installing French Doors with a DIY Transom

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.

Installing French Doors with a DIY Transom

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.

Installing French Doors with a DIY Transom

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 door knob.

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.

Installing French Doors with a DIY Transom

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

Installing French Doors with a DIY Transom

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.

Installing French Doors with a DIY Transom

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. Its basically a box with sheets of glass held in place with quarter-round moulding.

Installing French Doors with a DIY Transom

Installing French Doors with a DIY Transom

If you’d like a pro to install your doors, let The Home Depot’s Door Installation Service take care of it for you.

Browse our selection of French doors at The Home Depot.

Related Pinned Items