How to Treat & Clean an Old Barn Beam

Updated February 21, 2017

Without the presence of too much moisture, as wood ages, it hardens, rather than decaying. This makes barn beams and other construction timber a valuable commodity, but these one-piece beams are becoming harder to find. While laminated beams may be lighter and stronger, they do not have the same visual punch as a solid wood beam. Before incorporating a barn beam into your construction project, take some time to clean and treat it to restore the moisture content.

Vacuum the surface and any voids in the beam with a wet-dry vacuum to remove surface dust. Inspect the beam for any nails or other fasteners or hardware that may damage tools or cause injury during handling. Pull out old nails and other hardware with locking pliers.

Lay the beam on a sturdy work surface or a pair of saw horses. Mix a few ounces of wood cleaner, such as oil soap, to a quart of warm water. Wash the surface of the beam with a sponge dampened with the cleaning solution. Scrub the beam thoroughly using a nylon scrubber for stubborn soil. Plug in a fan or two and allow the air to circulate over the beam to dry it out thoroughly.

Rub the surface of the beam with a rag dampened in odourless white spirit to remove any oil or other residue that the cleanser may have missed. Allow the white spirit to dry to the touch. Apply boiled linseed oil with a clean rag to the entire surface of the beam. Boiled linseed oil is a finish product readily available in most paint departments at hardware and home improvement stores. Apply two more coats without waiting for the oil to dry to penetrate into the grain and restore the natural oil of the wood.


Apply the same techniques to an installed beam, with the added precaution to work carefully on the ladder. Spread dust sheets under your work area to aid in cleanup.

Things You'll Need

  • Wet-dry vacuum
  • Locking pliers
  • Oil soap
  • Sponge
  • Fan(s)
  • Rags
  • White spirit
  • Linseed oil
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About the Author

Mark Morris started writing professionally in 1995. He has published a novel and stage plays with SEEDS studio. Morris specializes in many topics and has 15 years of professional carpentry experience. He is a voice, acting and film teacher. He also teaches stage craft and lectures on playwriting for Oklahoma Christian University.