How to preserve fence posts

Updated February 21, 2017

If not properly sealed, wood fence posts will quickly suffer the repercussions of moisture and sun damage. Preserve your wood fence posts by treating them with an exterior wood seal and waterproofer. Choose either transparent wood seal to maintain the natural wood tone, or use a tinted wood seal to change the colour. Wood seals come in both water-based and oil-based varieties. Oil-based seals provide better penetration into the wood while water-based seals are much less vaporous. It is best to treat new fence posts at the time of installation and. Old fence posts can also be cleaned and resealed.

Make sure the posts are clean before sealing. A pressure washer and a deck wash can be used if necessary. The posts should be free of dirt, grease, oil and mildew. A brightening agent can also be used for faded posts. Allow washed posts to completely dry before applying seal. This may take a couple of days.

Use an electric sander with 100-grit sandpaper to lightly sand the fence posts.

Wipe down the posts with a tack cloth to clean the dust produced by sanding.

Apply the first coat of seal. Apply seal with a paintbrush, staining pad or sprayer. Quickly wipe up any drips or pooling. Work in the long direction to prevent horizontal overlap marks.

Allow the seal to dry according to the drying time indicated on the can (usually three or four hours, until the seal is dry to the touch).

Apply a second coat of seal. Allow the second coat to cure for at least one day before installing the fence posts.


Wood seal has noxious properties. Wear latex gloves to prevent skin contact and work outdoors or in an area that has been adequately ventilated.

Things You'll Need

  • Electric sander
  • 100-grit sandpaper
  • Tack cloth
  • Wood seal and waterproofer
  • Paintbrush
  • Sprayer (optional)
  • Staining pads (optional)
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About the Author

Mason Howard is an artist and writer in Minneapolis. Howard's work has been published in the "Creative Quarterly Journal of Art & Design" and "New American Paintings." He has also written for art exhibition catalogs and publications. Howard's recent writing includes covering popular culture, home improvement, cooking, health and fitness. He received his Master of Fine Arts from the University of Minnesota.