Tap to Read ➤

How to Trim Out a Window

Rimlee Bhuyan
Window trim gives a window a polished appearance and also enhances the décor of your home. Although installing your window trim is not hard to do, it can be a time-consuming project requiring a lot of patience.
We spend so much time and effort in doing up the interiors of our home with carefully chosen furniture, draperies and home décor artifacts. But we forget that some small details like installing trims and moldings can give the décor of the home more finesse and elegance.
Moldings around the door and window can completely transform the look of the house. The varieties of trims available in the market is virtually mind-boggling, but you need to choose one that best suits the architectural style of your house.
If your carpentry skills are fairly good, then you can install window trim yourself. This kind of DIY project, though easy, can be time-consuming and will require painstaking accuracy while taking measurements and cutting the molding.
There are basically two ways to trim out a window. One is the traditional method of framing a window where each of the four corners of the window trim are cut at 90 degrees. The second method is to install a stool (which is a small ledge) at the bottom of the window with an apron (casing) to support it.
The first method of installing window trim is suitable for modern homes, whereas the second method is suitable for older homes in which you need to preserve the architectural integrity of the house. For a novice, the first window molding idea is an easier project to undertake.

Trimming Out a Window

Things required

  • Wood trim
  • Miter saw
  • Hammer
  • Nails
  • Straightedge
  • Hand held drill
  • Drill bit
  • A combination square
  • Tape measure

Procedure

Prepare the Trimming
The first step in trimming out a window is to prepare the trim. To do this you have to sand the wood trim with a fine grit sandpaper until it is smooth. Next apply a stain of your choice making sure that the stain color matches the décor of your house.
Prepare the Window Jambs
You have to make sure that the window jambs are parallel to the wall. Window jambs are located inside the frame of the window. If the window jambs are not parallel to the wall, then you need to level it by using a straightedge. Now mark a reveal line with a pencil using the window jambs as a guide.
Cut the Trims
Once this is done, cut two long sections of the trim that you had prepared earlier at 45 degrees, with the help of the miter saw. When you align these pieces together they should meet at a perfect 90 degrees. This is one of the hardest part of the installation process, so it is better if you cut some "test pieces" to get a perfect fit of the trims.
Install the Top Trimming
Place the top trim over the window frame making sure that it aligns perfectly with the reveal line that you had marked earlier. With the help of a pencil, transfer the reveal lines that you had marked earlier from the head jambs to the top trim. Holding the trim in place with your hand, drill nail holes on the trim with the hand held drill. Insert the nails to finish.
Prepare the Side Trim
When you are done installing the top trim on the window, place the other trim on one side of the reveal line making sure that the corners of the trim fit tightly without any gaps. Once you have established this, place this over the window frame, flush with the corner of the top trim. Measure and mark the length of the side trims, and tack it in place.
Install the Side Trims
Cut the trim to the required dimension with the mitered saw and nail it in place by drilling holes with the hand held drill. Hammer the nails in place, making sure that the nails look inconspicuous. Now nail both the corners of the trim using light strokes with the hammer so that you don't split the trim edge. Repeat the same process on the opposite side.
Install the Bottom Trim
Lastly fit another miter trim on the bottom of the window frame. Overlap this trim over the other corner and mark the point where the trim overlaps. Cut the trim with a ¼ inch overhang, slide the trim into the corner of the side trim. Now cut the edge of the trim with a miter saw and nail this bottom trim in place with hand held drills and nails.
This was how you trim out a window. If you take precise measurements at every step of the installation process, you will not have any difficulty in trimming out a window.