How to Fix a Cracking Log Home

Horizontal cracks running along the exterior walls of a log home are known as "checks," and are a natural part of every log home. They typically occur as the logs age. While they are not usually indicative of serious problems, they should be examined and, when warranted, quickly repaired.

Fixing cracks in log walls is a simple process.

Usually, only upwards-facing checks should be filled, so that they don't collect rainwater and cause mildew or rot. Fixing such checks is a simple process that can be completed in as little as 30 minutes.

  1. Examine log walls for upwards-facing cracks. Cracks less than 1/4-inch wide can be ignored.

  2. Clean the cracked areas thoroughly, paying strict attention to the areas immediately inside the "lip" of the crack. These areas must be dry and free of rot for the sealant to properly adhere to the wood. If water is present, wait for it to evaporate before continuing. If rot is seen, cut away the rotted material until you have a solid wood surface.

  3. Measure the width of the crack. For cracks exceeding 1/2-inch in width, insert a sized foam backer rod that has been cut to proper length. These rods come in many sizes and should fit snugly into the crack, leaving at least 1/2-inch of space below the log surface for the sealant to fill. For cracks less than 1/2-inch in width, a backer rod is not usually needed.

  4. Squeeze a good quality commercial water-resistant sealant into the crack. The sealant must fill the area completely. Use a caulking gun to apply sufficient force to get the product deeply into the crack. A ladder may be needed to repair cracks high up on walls.

  5. Use a finger to smooth the sealant and even it out so that it is flush with the log surface.

  6. Let the sealant dry according to manufacturer directions.

  7. Tip

    Be sure the cracked area is fully dried before beginning any repairs to avoid trapping moisture inside the crack. Make the repairs when rain is not forecast for several days to promote even drying.


    Always follow manufacturer's directions when using any log repair product.