How to Install Flexible Molding

  • 2 hours
  • Intermediate
  • 50
What You'll Need
Measuring tape
Flexible molding
Miter Saw
Construction adhesive
Nail gun
Wood putty
Putty knife
Sandpaper or power sander

Flexible molding (sometimes called “flex molding” or “flex trim”) is a durable material ideally suited for making decorative moldings in curved or unusually shaped areas in your home where wood molding is just too tricky to install. Made out of polymer or polyester resin, flexible molding is readily available in hardware stores or on the internet. Flex molding is easy to paint and isn’t much more difficult to install than regular wood molding, so it's becoming increasingly popular. Check out the steps below to learn how to efficiently and successfully install flexible molding in your own home.

Step 1 - Measure and Trim Your Molding

Use your tape measure to determine how many linear feet you need to cover with your flex molding. Then, measure out this amount on the molding itself, making a note with a pencil or chalk at the spot the molding needs to be trimmed. You’ll have to use a saw to trim the molding down to the appropriate length.

Step 2 – Warm it up

Whether you’re working in the winter or just live in a cold climate, make sure that the molding is warmed up before you try to install it. Otherwise, the molding could become brittle and splinter, or break when nailed down. Spread the flexible molding out in a warm dry place, preferably a safe distance from a heater, for about 30 minutes to an hour before you get to work.

Step 3 – Apply Adhesive

In order to make sure your flexible molding sticks in place while you install it, apply some construction adhesive (polyurethane adhesive is recommended) to the back. Make sure to apply the adhesive smoothly and in a regular, wave-like pattern. This will not only bond the molding to the wall or ceiling, but will also help to prevent the flex molding from undesirable expanding or contracting with changes in the weather.

Step 4 – Nail the Molding Down

Next, affix the molding in the area you’d like it to be installed. You may need an extra pair of hands to help you out, as the molding might start to sag or contract as you work with it. Take your nail gun and nail the flexible molding into place.

Step 5 – Fill in the Holes

In order to erase any unsightly nail holes, apply wood putty over them with a putty knife. Wait for the putty to dry before painting. This may take from 30 minutes to an hour or more.

Step 6 – Sand and Paint

Use sandpaper or a power sander to smooth out any uneven edges and to ensure that different sections of molding line up seamlessly. This may take a little longer than with regular wood molding, given flex molding’s propensity to move during installation. Finally, paint the flexible molding or apply the stain as desired, and let dry.