How to Replace Wooden Exterior Window Trim

A home with wood trim.
  • 2 hours
  • Intermediate
  • 30-50
What You'll Need
New molding
Wood putty
Miter saw
Nail set
Pry bar
Paint primer

When your exterior window trim becomes damaged and you need to replace it, you can choose between wood or plastic. Each has advantages and disadvantages, including price and maintenance. Whichever type of exterior window trim you choose, this article briefly explains how to complete the job.

Removing Old Trim

Use your pry bar. Place a wood strip beneath the bar to keep it from damaging your siding. Pry the old exterior window trim loose.

Attaching New Trim

Measure the pieces of trim you plan to attach. With your miter saw, cut each corner at a 45-degree angle.

To attach plastic trim, apply glue to its rear surface and tack it with finishing nails to hold it in place. For wood trim, attach it by driving in finishing nails. Fill in holes with wood putty.

Caulking and Painting

Apply caulk around the edges and allow the caulk to dry. Paint the new trim with two coats of paint. Allow the first coat to dry before you apply the second coat.