Simple Window Trim and Door Trim

Window trim and door trim with old world elegance—it’s actually easier than standard trim

Tradition window and door trim looks more complicated than picture-framed trim, but it's actually simpler and more forgiving. It also hides uneven walls and jambs better.

By the DIY experts of The Family Handyman Magazine

Traditional vs. modern trim

This traditional trim style for windows and doors may look like it requires old-school carpentry skills, but the truth is, it’s easier to install than contemporary trim. Modern trim—four pieces of casing that “picture frame” a door or window—requires wide miter cuts, which look sloppy if they’re not perfect. Traditional trim is more forgiving. While it also requires miter cuts, they’re shorter and less visible. And the most prominent joints are assembled with simple square cuts.

If you’re nervous about installing the mitered crown molding that tops off the window and door trim, check out “Make Your Own Moldings” below, where we show you how to make a simple router-shaped version that doesn’t require any miters. We’ll walk you through the steps and give you some tips and pointers for cutting and installing the moldings to create this classic trim style.

Project Details

Time: 90 minutes per window or door.

Skill level: Intermediate to advanced

Cost: $35 per window and $40 per door for pine trim. Oak or maple trim would cost about twice as much.

Tools: A miter saw with at least a 40-tooth blade. A pneumatic trim nailer and compressor, and a table saw and router with a 1/4-in. roundover bit if you want to make a stool and fillet like the ones shown here.

Prepare the jambs

The first step in any trim job is to prepare the jambs for trim. If you’re replacing trim, pry it off and remove the nails from the jamb. Then scrape or sand the face of the jamb to smooth out any paint or finish that’s built up. Finally, mark the reveal on the jambs to show where the edge of the trim goes. A combination square set to 1/4 in. works great for marking the reveals. But you can also use a compass to scribe the marks, or simply measure and mark the reveals.

If possible, set up your miter saw in the room where you’re installing the trim. Having the saw nearby will save you a ton of time. I like to rough-cut the casing and other moldings to length, allowing a few extra inches, and label them to make sure I have all the material I need and won’t accidentally cut the wrong piece.

For tips on buying or making the moldings you’ll need, see “Traditional molding” below.

Mark the trim, don't measure

With the moldings and other parts cut to rough length, and the reveals marked on the jambs, the fastest and most accurate method for marking the trim for cutting is to simply hold the molding in place and mark it (Photo 1). It's foolproof. You don't have to measure, do math or remember any numbers.

Figure A: Window Trim Parts

Trim terminology can be confusing. Here's a labeled photo to show you the names of the window trim and door trim parts we used.

Window and door trim parts

Install the window casings, stool and apron

The order of trim installation for windows (and door trim as well) varies a little depending on whether you’re working on old double-hung windows or newer-style windows. On older double-hung windows, the stool rests on the angled sill and butts into the lower sash (check out Figure A if you’re not sure what a stool is). You have to notch the new stool to fit, and nail it to the windowsill before you install the side casings. But on newer windows like the one shown here, the stool isn’t notched and doesn’t rest on the sill, so it’s a little trickier to nail. An easy way to attach this type of stool is to install the side casings first, and then nail the stool to them (Photo 2).

The stool should protrude past the casings by about an inch (Photo 2). To find the length of the stool, make a mark 1 in. beyond the casing on both sides. Then hold the stool up and transfer the marks. After the stool material is cut to length, round the edges and ends. Or if you want a little fancier stool, rout the edges with a more decorative bit. You can even buy a special stool-shaping bit, but you may have to order it.

With the side casings and stool in place, the next step is to install the apron under the stool. Start by cutting a 45-degree miter on each end. Mark for the long point of the miters by resting the apron on the stool and making marks where the outside edges of the casings intersect the apron material. Snug the mitered apron against the bottom of the stool and nail it to the framing under the window. Then cut returns and glue them in (Photos 3 and 4).

Photo 3 shows how I used a sacrificial piece of wood behind the apron material. Any flat scrap of wood will work. This sacrificial backer board prevents the skinny piece of molding you’re cutting off from getting caught by the blade and flung through the gap in the fence. Don’t attach the sacrificial board to the saw. Just hold it in place along with the molding you’re cutting. Then reposition it with each new cut so you’re always making a fresh cut through the sacrificial board.

Tips for Choosing, Buying and Making Your Own Traditional Molding

Shopping for trim
We found the wide casing and base blocks at the home center, along with the fancy casing we used as an apron. We had to go to the local lumberyard for the 2-1/4-in. crown molding. If your local home center or lumberyard doesn’t have what you want in stock, ask to see a molding book or chart that shows what styles are available to order. The Internet is also a good place to search for traditional moldings for door trim and window trim. Here are a few links to help you get started.

Make your own moldings
You don’t have to buy moldings. With a little ingenuity and a few standard router bits, you can make your own door and window trim. Figure B shows an example of a cap molding for a head casing that we made by stacking two pieces of 3/4- in. oak. Shaping the edges of wood strips with a router and stacking them to make bigger moldings is a great technique for making your own moldings.

You can make moldings with a handheld router, but it’s a lot easier and faster to mount your router in a router table. The Ryobi router table shown here (about $100) works well, but there are plenty of other options. For plans to make your own, see this DIY router table .

The photo shows how to use featherboards for safer and more accurate routing. You can make your own featherboards, or buy plastic ones like the ones in the photo for about $10 to $20 each.

The ends of the boards shown in Figure B are routed. This method eliminates the need for mitered returns, but it does expose end grain and means you have to cut the parts to length before you shape them. To rout the end of boards, use a shop-made push block like the one shown here. It serves two functions. First, it allows you to hold the board square to the fence. And second, the push block prevents splintering by providing a backer behind the board you’re routing.

Hold the wood with featherboards.
Build a simple push block to rout ends.
Figure B: Router-shaped cap molding

Build the head casing assembly

The final step for both the door and the window trim is building and installing the head casing assembly. It’s made up of three parts: the fillet, a 1x6 and the cap molding. Traditionally this cap molding was solid, but since a solid molding this large is hard to come by, we substituted 2-1/4-in. crown molding. If you have a router and want to avoid using crown molding, check out Figure B above for an attractive alternative.

Start by setting the 1x6 on top of the side casings and marking it at the outside edge of each casing. Cut the 1x6 to length. Then cut the fillet 3/4 in. longer than the 1x6. Round over the edges and ends of the fillet to make a bullnose shape using a router and 1/4- in. round-over bit. Nail the fillet to the bottom of the 1x6.

Finish the head casing by wrapping the front and sides of the 1x6 with crown molding. photos 5 – 8 show how. Make a jig (photo 6 and Figure C) to hold the crown molding at the correct angle while you cut it. Remember to set the crown molding upside down in the jig. Mark and cut the short pieces of crown molding (photos 5 and 6). Then cut a miter on one end of the long front piece and hold it in place on the 1x6 to mark the opposite end for the miter (photo 7). Cut the second miter on the front piece.

Check the fit by holding the short mitered ends in place against the front crown molding. If the miters are tight and everything fits, complete the head casing by nailing the crown molding to the 1x6 (Photo 8). Complete the window trim by nailing the head casing assembly to the framing above the window (Photo 9).

Figure C: Crown Molding Cutting Jig

This jig holds the crown molding at the correct angle in the miter saw, so it's easy to make accurate miters every time. Glue two strips of scrap wood together at a right angle. Then set the crown molding upside down in the jig and mark the position of the stop. Glue the stop to the bottom and you're ready to cut some moldings.

Cutting jig for crown molding

Finishing up

If you’re installing painted moldings like ours, see Trim Painting Tips for advice on how to finish your moldings with a flawless coat of paint. If you prefer natural wood, check out Finishing Wood Trim With Stain and Varnish.

A DIYer's success story

Matt Timpany finished a huge empty room in his basement into a home theater, pool room, game room and full bath.

Matt’s an avid, self-taught DIYer with 15 years of woodworking experience. For this 1,400-sq.-ft. basement remodel, he went a little outside his comfort zone and also tackled the wiring and plumbing, which he did successfully except for one plumbing mistake, which, in Matt’s words, led to some “training cost.” Between his dad job and his day job, this project took Matt two years and three months to finish.

Door trim is similar

Trimming a door is just like trimming a window, except you start out with base blocks at the floor, as shown here. The base blocks should be about 3/8 in. wider than the casings. Trim them if necessary. The height of the base blocks should be about 1 in. greater than the height of the baseboard you're planning to install.

Door trim

Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • Miter saw
  • Air compressor
  • Air hose
  • Brad nail gun
  • Tape measure
  • Combination square
  • Hearing protection
  • Orbital sander
  • Router
  • Router table
  • Safety glasses
  • Utility knife
  • Wood glue


Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

  • Casing for window and door trim
  • Fillet molding
  • Crown molding
  • Window stool
  • Window apron
  • Base block for door trim

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