As log cabins adjust to their environment, it is normal for the logs to expand, contract, crack and split. Sealing and caulking cracks and gaps are part of the routine maintenance of a log cabin and help avoid water damage and infestations of insects and small animals.
Walk around the exterior of your log cabin and examine its condition. Use a stick of chalk to mark any gaps or cracks that are more than 1/4 inch wide, so that you can locate them easily when you make the repairs.
Load your reusable foam gun with a can of expanding foam sealant and squeeze the product into any gaps and cracks. There are many sealant products on the market that are suitable for this task. For example, PurFill Expanding Foam Sealant is a moisture-curing foam that expands in place to form a solid seal.
Use a piece of sandpaper to smooth off the sealant once it is completely dry.
If possible, apply sealant on a dry day.