Finishing the Opening: Door Jambs, Half-Wall Ledge, and Trim (DIY)

The wall is down (more here), the drywall is up (more here), and now it’s time for trim. After the drywall work, I focused on the half-wall ledge and the door jambs before tackling the trim.

I actually enjoy trim work. It demands concentration and attention to detail, but transforming rough edges into crisp white borders is very satisfying. For the half wall, we liked a neighbor’s treatment—a wooden platform on top with trim beneath—so we picked up an 8″ wide, 4′ long pine plank to form the top ledge.

The plank needed some fitting. One end was shortened with a straight cut, while the other required a notch so the ledge would overhang evenly on both sides once the interior trim was installed. We measured and re-measured the wood to avoid mistakes…

…then I took the plank to the driveway for cuts: a jigsaw for the notch and a miter saw for a clean straight end.

Before installing the ledge I sanded the edges to soften the corners—no one wants a sharp edge when walking past the new opening.

Fit-wise we got lucky: it was perfect on the first try. It looks long in some photos only because the side trim wasn’t installed yet; once the trim is in place there will be a slight overhang under it, harmonizing with the style of many windows in our house.

I tacked the plank into the framing with a couple of finishing nails at each end. We’ll prime and paint the ledge white to match the trim. With the ledge in place, we moved on to installing the door jamb.

Our opening matched a standard jamb width of 4 5/8″, so I used a pre-packaged door jamb kit from Lowe’s. Because our opening was taller than a standard 3′ doorway, I bought an extra $6 side piece to extend the top jamb.

The jamb covers the drywall edges and paneling so that when trim is added, the opening looks seamless. Although instructions suggested assembling the jamb as one piece and leaning it in, our slightly nonstandard dimensions made that impractical. Instead we hung each jamb piece separately, which worked well: cut the short side first, hold it in place, and nail it with finishing nails.

Next we slid in the short section of the top jamb and nailed it in. The opening started to look like a proper doorway, and the trim would finish the job.

We had to join two pieces for the 92″ top jamb because a single piece of that length wasn’t available. A thin bead of caulk and a coat of paint will make the seam nearly invisible. I also used a nail punch to sink each finishing nail head for a smooth finish (more about the nail punch here).

With the jamb assembled and secured, and the ledge completed, we moved on to trim. I won’t cover every step of trim installation here (you can find a detailed walkthrough when we re-trimmed our bathroom), but the process involved careful measuring, mitered cuts on the saw, and precise nailing with the nail punch to avoid dings.

We also added narrower trim beneath the ledge to visually ground it and echo the treatment used on our picture window and other windows throughout the house. This gave the half-wall a more finished, balanced appearance and provides a practical place to set small dishes or drinks when entertaining.

• We copied a neighbor’s attractive half-wall treatment and liked the result.
• The smaller trim under the ledge matches how many of our windows are treated, creating consistency throughout the home.

During demolition we removed several lengths of baseboard. Luckily most pieces survived intact so we didn’t need to buy new baseboard. A bit of touched-up paint and fresh caulking will make the reinstalled baseboard look seamless again. Some quarter round near the future flooring transition was left unfinished since it may be removed during the floor work, but most baseboard was reinstalled to keep the space looking polished while other projects continue.

Here are views of the opening from both sides with the finished jamb and trim—definitely more doorway-like. We’ll paint the wood ledge white to integrate it with the surrounding trim.

To help the space feel more like a kitchen and dining room, we moved some furniture back in. The kitchen chairs are temporary placeholders until we pick counter-height stools that are lighter in appearance—perhaps acrylic—to keep the look airy. Expect a little chaos while we finish other projects like counters, cabinet painting, lighting, flooring, and backsplash.

We also scored the final cabinet for the peninsula at the ReStore—free, actually. The donor had left a set out in the rain and the store couldn’t sell them, so they offered it to us. After airing it out and inspecting it for water damage, it looked fine and turned out to be the closest match we’d found to our existing doors and drawers.

The tape lines on the floor mark where the peninsula will end and where a 12″ counter overhang will reach, which helps visualize the final layout as we move forward.

The opening really brightens the kitchen by bringing more daylight into the space. Once we paint the cabinets and install white counters with mocha cork flooring, the kitchen will feel even lighter and more cohesive.

Now you can enjoy views from the dining room into the kitchen and fireplace—an improved flow that makes entertaining and everyday life more pleasant.

We also love the new sightlines: a peek through to the hallway and the sunny kitchen beyond looks great from the office. The pets adjusted quickly too—Clara happily explored the new route the day after we opened the wall, and Burger cuts through the doorway all the time now.

For comparison, here are a few older photos from right after we moved in last December. It’s amazing what eleven months and steady progress can do.

All told, finishing the entire opening ourselves—drywalling, installing door jambs and the ledge, and adding trim on both sides—cost about $90 in materials. Hiring a contractor would have been roughly $250, so DIY saved us about $160.

What did you do this weekend? Any door jamb, ledge, or trim projects underway? We spent a fair amount of time just standing around and admiring the new doorway—completely worth it.