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Add Flair with Trimless Windows

Finish Carpentry, Mantels. Trim, Molding, Trim Carpentry, Windows & Doors January 13, 2010 Sonia

By Mark Clement


Flaring the windows delivers depth and mass, and the lack of casing leaves more room for ceiling trim.



A benefit of working on old houses is that I get to see how they used to do it. Sometimes that’s good, other times the phrase “They don’t build ‘em like they used to—thank God!” comes to mind.

One good design trick in these older homes is trimless windows. In other words, instead of wood jambs and casing, I flare and bullnose my window returns using drywall and cornerbead. Now, this isn’t some cheap, money-saver disguised as a fancy technique because it takes some effort—and the payoff is terrific!

Prepare for design mumbo-jumbo: Flaring the windows delivers depth and mass without making a window feel like a tunnel through the wall. It also makes modest rooms feel much bigger. Another ROI (return on investment) is that the top of the window terminates in a soffit with no casing. That means there’s about 3-1/2 more inches between the top of the window and the ceiling. These extra inches allow room for larger, more elaborate crown molding above the windows. The end result is a room that transforms from a boring box to a stately room.

The first step is a window worth trimming out in the first place. As part of this room’s overhaul, I installed Simonton’s new Driftwood replacement windows. The color is pleasant and muted on both the interior and exterior and enables me to really play with exciting wall colors. White would work too, but the benefit here is that I have a choice.

I might have had it easy in this project because the room was gutted, so I had to reframe the walls. If you’re re-detailing a stick-built house (and/or not gutting the room) to accommodate this detail, at the minimum you’ll have to consider widening the opening to accept the flare. This could mean re-framing a few king studs, jacks and the header. You can also experiment with a more shallow flare, too. This window opening, so you have a frame of reference, has a rough opening about 6 inches wider than the window on each side—this amounts to a 16-degree flare on each side.


Existing Trim Details

On this house, the window-weight shafts had a simple trim detail that I chose to keep. Should you find this on your project, here’s how I dealt with it:

I used the existing molding on the window-weight shafts to layout and mark the new sill (1-by-10 knotty pine; the pine adds just a hint of earthy texture and color in the finished product). And, to minimize notching a finished piece, I map out the sill and install it now, using the drywall to hide the ends. I let the ears of the sill into the field of the wall drywall. This usually takes a few steps to scribe it right, which is why I use a scrap board to make the pattern.

Once the template fits, I transfer it to the finished piece and cut. I then rout a bullnose on the top and bottom of the front three edges. It’s worth mentioning that, theoretically, I’d stop here to sand and urethane the sill to protect it during installation. The reality of progress, however, T-bones that notion like a Hummer hitting a Hyundai, so I keep building.

Scribe the sill. Cut it out. Test the fir and install.

Scribe the sill. Cut it out. Test the fir and install.

Now that the sill is scribed I can remove existing window-weight shaft casing. On this house, it’s 1/2 inch stock with a beaded window stop.

Remove the existing trim.

Remove the existing trim.

For a house-sized project I’d buy the parts and simply size them as needed on site like any other trim. I planned to do that for this room because my lumber yard’s trim catalogue calls the beaded molding a “stock” item. Of course, what they meant to say was “special order.” Long story short, I used a table saw to mill it on site from 1/2-inch base molding stock. Layout Tip: Forget measuring. Use the piece itself as a gauge to set your table saw.