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How to Fix a Metal Barn Roof Leaks

Sheet metal often appears on barns because it is durable, long-lasting and highly weather-resistant.

Keep your barn safe from water damage by making seams and screws watertight.
Roof leaks often occur in valleys where water accumulates; however, barns primarily consist of only two slopes and do not have any valleys. This means that leaks in a barn roof are likely due to water seeping into the holes of loose roofing screws or into the seams between sections of sheet metal. Repair the roof promptly, as leaks will quickly cause moisture damage to the barn's interior wood structure. .

Put on boots with decent traction, as metal roofs are slippery. Don't work on the roof if it is wet. For extra precaution or if the barn has a steep slope, anchor yourself by tying one end of a rope around your waist and the other end to a tree or solid structure on the opposite side of the roof. Walk along the screw heads to enhance traction when walking on the roof. If the roof does not have sheathing, walk only along rafters.

Clean the seam areas using roof cleaner and a scrub brush. Remove any flaking coating or rust with a wire brush. Rinse with fresh water and treat any remaining rust with rust converter.

Paint any areas where coating had flaked away with roof primer and a paintbrush.

Remove screws along sheet metal and roof cap seams, using a drill with a socket bit. Apply consistent beads of metal roof sealant with a caulk gun under the laps. If the sheet metal is thin and flexible enough, you may be able to get the nose of the sealant tube under the laps without removing the screws. Replace the screws after applying the sealant. Allow the sealant to cure for eight to 12 hours.

Paint the seams with waterproof metal seam sealer. While the seam sealer is still wet, cover the seams with 4- to 6-inch strips of high-tensile-strength metal roof fabric. Paint a coat of seam sealer on top of the strips of fabric.

Inspect all other screws to locate loose screws. Tighten these screws and cover the screw heads with metal roof sealant. If a screw is stripped, replace it with a longer roofing screw.

Things You Will Need

  • Work boots
  • Rope (optional)
  • Ladder
  • Roof cleaner
  • Scrub brush
  • Wire brush (optional)
  • Rust converter (optional)
  • Roof primer (optional)
  • Paintbrush
  • Drill with socket bit
  • Metal roof sealant (caulk-type)
  • Caulk gun
  • Waterproof metal seam sealer
  • Roofing screws (optional)

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.