DIY Modern Door Casings

Do you want to take the look of your home up a level??? It’s all about the details! One way is with custom door trim (casing). We moved into a 90s-inspired home recently, and I enhanced the look with these DIY modern door casings! Super easy to do, and it’s sure to add a contemporary vibe to your space. I am slowly working my way through the first floor, so for some of the photos, the doorways might look like they are in a different area–and they are! I collected the best shots to showcase how to do this project.

Materials for DIY Modern Door Casings

• Primed Pine Casing 3.25″ width
• Screen Mouldingfor narrow sides
• Corner Moulding for regular sides
• Painter’s Tape
• Brad Nails at 1.25″ length
• Wood Fill
• Sandpaper
• Behr Paint in Eggshell Finish, Intellectual

Tools I Used to Install Modern Door Trim

• Box Cutter
• Pry Bar
• Rubber Hammer
• Putty Knife
• Oscillating Tool
• Tape Measure
• Miter Saw
• Painter’s Kit with Mini Rollers & Brush

Remove the Old Trim

To get started, you’ll need to remove the old trim. If it’s just wood, you should be fine to remove. If it’s been painted over, or caulked, you may want to use a razor or box cutter to prevent any rips in the wall paint. Score along the edge where the trim piece meets the wall.

Then, using a pry bar, try to get into that separation. If you can’t, try using something more narrow, like a putty knife–thin enough to make space for the pry bar. Use the rubber hammer to insert the pry bar. The trim should pop off in sections. You may have some finishing nails to remove with pliers, or pound into place with a hammer.

Adjust the Base Trim

If you’re going from traditional door casings to something more modern, you’ll most likely be adding width to the casing, like I did. I went from a 2-2.5″ piece to 3.25″ which meant the base trim needed to be cut to fit. I held the new trim piece up to mark my cuts.

I used my oscillating tool (multi-tool) to cut this section off.

Measure for Height & Width

You’ll take long measurements. If you’re adding modern door casings, like I did, the width and height will add extra length to the entire door, so using your old trim to make cuts is not ideal. You’ll be cutting some of the edges at a 45º angle, so always measure long to get started. When you put it up after the first cut, you’ll get an idea of how much you still have to cut off.

Make the Cuts

On the sides of your doorway, you’ll start with the 3.25″ wide moulding. Two of the pieces will placed flat against the floor, with one top edge of each cut at a 45º angle. Because I used this moulding, one edge is rounded off and one is flat. I chose to use the flat edge, tucking the rounded edge under the corner piece. Using the flat side ends up looking more modern, so it’s really up to you and the look you prefer. Just make sure when you make the side cuts at 45º that they are angled in properly. I always cut a little bit long on my first go, so I can put everything in place and make sure angles are correct.

The top piece of casing will be cut at 45º on both ends–in opposite directions. When you’re working alone, painter’s tape can be your BEST friend, especially when working with long doorways and lightweight trim. This is a process, making a number of cuts to get as close as possible. I leave tape in place so I can make adjustments as the pieces are cut to fit.

Nail the Casing

Once the pieces are dry fit in place, you can nail in place with a nail gun. I used 1.25″ nails.

Fill Nail Holes

Use a paintable wood filler to fill in any holes created by the nail gun. Then, either wipe with a damp cloth, or wait until it dries to lightly sand.

Add the Edge Trim

For these modern door casings, I finished the look with an edge piece. Most of the edge pieces I used was the Corner Moulding that wraps around the edge.

For a few of my doorway openings, the side closest to the exterior wall is so close that I had to swap the corner for a simple piece of Screen Moulding. No one could tell the difference because the edging in the front is a perfect match! I did most of the measuring of these pieces before painting anything so I wouldn’t scratch the paint. The edge pieces got painted just before installing them, which kept me from getting paint on the wall–or having to tape.

With these pieces, it’s important to practice cutting a 45º angle. It’s easy to get mixed up since you’re cutting an “L” shape of wood into an angle. I used the same method–cut long and tape in place till the sizing is right. The same finishing nails are used to fix these to the casing–just angle in toward the wall, so you don’t accidentally nail in front of the casing.

Painting Details

Because there will be a corner piece going on the exterior edge, you can paint the wide trim pieces once they are installed. A roller paints them nicely–and quickly, but using a paint brush is simple, too. If you’d like to protect the finish from brush strokes, consider using Floetrol to thin your paint.

What I’d Do Differently Next Time

If I were doing this project again, I would cut every piece slightly long, dry fit everything with painter’s tape, and paint the edge trim before installing it. Those small steps made the finished casing look cleaner and saved me from touching up the wall afterward.

DIY Modern Door Casings: What Do You Think???

Are you ready to try this project in your own home? I’d love to see!

Common Questions about My DIY Modern Door Casing

Can I install modern door casing myself?

Yes, this is a manageable DIY project if you are comfortable measuring, cutting trim, and using basic tools like a pry bar, miter saw, and nail gun.

What size trim did you use for the modern door casing?

I used 3.25-inch primed pine casing for the main trim pieces, then added corner moulding or screen moulding along the edges depending on the doorway.

Do you have to remove the old door trim first?

Yes, removing the old casing gives you a cleaner finish and allows the new wider trim to sit properly around the doorway.

What paint color did you use?

I used Behr Intellectual in an eggshell finish.