And don't allow the tops of the log overhangs to be flat, which only adds to the problem. Make sure chimney and gable dormers are properly flashed. This is a problem in any home, but it's worse on a log home. If you see water leaking into the home, you can be sure it's also saturating the logs. Make sure all windows and doors are flashed above the trim top, or at least have a log with a positive drip edge.
Exterior sealing between the logs is essential.
Systems such as the grooves with tape sealants are not enough. The water will get in. Penetrating Epoxy Preventative Measures Make an active search for wood problems. Open cracks, checks, soft wood, deterioration, rot - when the weather is dry. Epoxy will not displace water in wet logs.