How to Paint Roofing Tar on Fence Posts

Roofing tar is a traditional way of protecting fence posts. The tar adheres to the fence posts so that nothing can penetrate, prolonging the life of the wood by keeping insects and rot away. This method still works today and, while not attractive, treated fence posts don't need any maintenance. Treat your fence posts as soon as you get them, and they will last for the lifetime of the wood.

Step 1

Open a bucket of roofing tar and put on gloves. 

Step 2

Dip a wide bristle paintbrush into the roofing tar so three-quarters of the bristles are coated.  Let the excess drip off.

Step 3

Paint the fence posts so they're thoroughly covered in the roofing tar.  Use the end of the paintbrush to work tar into any of the groove or indentations in the fence posts. You need a thorough coating to keep insects and rot out of the posts.  Don't worry if the tar looks uneven, it serves a functional, not aesthetic, purpose.

Step 4

Continue painting the fence posts until they're all covered.  The roofing tar will take 12 to 24 hours to cure, depending on the weather conditions, such as humidity.

Things You Will Need

  • Protective gloves
  • Bristle paintbrush


  • Dip your fence posts in a bucket of roofing tar before installing them in the ground. Ensure two-thirds of each fence post is covered in roofing tar, and then lay each across another fence post so the dipped end is in the air while the tar sets.
  • Creosote and motor oil are two other substances that were traditionally painted on fence posts to protect them.

About the Author

Shara JJ Cooper graduated with a bachelor's degree in journalism in 2000, and has worked professionally ever since. She has a passion for community journalism, but likes to mix it up by writing for a variety of publications. Cooper is the owner/editor of the Boundary Sentinel, a web-based newspaper.