Installing Window Trim

Example of Wrap Around Window Trim

Installing window trim is an easy job for a homeowner who is comfortable with basic woodworking. While some window trim methods are complex, the common wrap around style of trimming interior windows requires very little skill.

Required Tools and Materials

This project requires a few basic woodworking tools and materials to complete. Here's some basic DIY advice for choosing the correct items for the job.

  • Tape measure: While tape measures can be found at any price point, plan on spending a few dollars extra to get a sturdy tape that is at least 25 feet long.
  • Hammer: A lightweight hammer will be fine for this project. Select a hammer that feels comfortable for you.
  • Nail set: This tool is used to push the head of the nail below the surface of the wood. It is essential for any fine woodworking project.
  • Wood putty: Match wood putty to the type of wood you use to further conceal nails or imperfections.
  • Saw: A small hand saw and miter box is fine for most small woodworking projects such as this one.
  • Trim: In most cases, window trim is made of wood, although composites are gaining popularity. Take time to try to match any existing trim to the trim purchased for the windows.

Installing Window Trim Using the Wrap Around Style

Use these simple techniques to create wrap around style trim to frame any window in your home.

  1. Begin by taking the measurements of the window. This should be the distance between each of the inside edges.
  2. Decide how wide the reveal of the trim should be. Add this measurement to the window measurement. A common reveal is 1/8 inch, so add 1/4 inch to the measurements. Also take into account any possible obstacles, such as interior window shutters or window screens.
  3. Decide how to finish the corners of the trim. Commonly the corners are mitered at a 45 degree angle to create a clean corner, although this is not a requirement. In general, you should finish the corners so they match any other trim in the house.
  4. If the corners are to be mitered, make a 45 degree cut on one end of the trim.
  5. Next, using the shorter side of the trim, mark out the length calculated in step two.
  6. Make a cut at that mark, making sure that the angle of the miter is a mirror image of the other end.
  7. Tack the piece into place using two finishing nails.
  8. Cut and attach the rest of the pieces using this measuring technique.
  9. With all of the pieces of trim in place, double check that the corners are tight and fit together properly.
  10. Add additional finishing nails to secure the trim into place. A good rule of thumb is to use a nail every eight inches.

Finishing the Trim

With the trim secured around the window, the finish work can begin. The quality of the finish work will determine the overall appearance of the trim, so work slowly when completing these steps.

  1. Get a nail set and use it to set all of the nails.
  2. Fill the nail holes with putty.
  3. Once the nail holes are dry, sand the area thoroughly to ensure the putty is not noticeable.
  4. Stain or prime the trim, working with a high quality brush to minimize visible brush strokes.
  5. Finish by painting or sealing the trim.

Other Things to Consider

While the wrap around style works for most window types, it is not suitable in all situations. In most cases, matching the trim already present in the house should be a priority. If the cost of the trim is a concern, try to match the style, but use the cheapest type of wood trim available. The trim can be painted to conceal the quality of the wood. This type of compromise is far better than choosing a very plane trim for a home that already has highly ornate woodwork.

Installing Window Trim