Cracks in the logs
Logs naturally do develop some cracks or checks. As wood dries, the difference in surface tension and moisture gradients between the inner and the outer parts of the logs cause checks. This is part of the charm of the log home.
These cracks can face up or down, depending on where they are on a log. Logs with cracks that face upward can be susceptible to rot because they allow the water to travel deep into the logs, where rot starts. The more exterior areas of logs can usually dry out after a rain because of the wind and sun, but the more interior areas can remain wet longer. When this happens, they can reach the right moisture point that allows rot fungi to grow.
Here are the three criteria we generally use when determining if it is necessary to caulk checks on log homes:
- The checks need to be over 1/4" wide
- The checks need to face upward on the log
- The checks need to be in vulnerable places
If all these criteria are met then the check needs to be filled.
Here is how we recommend it be done:
- Stuff flexible backer rod such as SOF rod into the check to about 3/8" from the surface.
- Sometimes we use painters’ tape to mask off the surface of the log to prevent caulking from being smeared on the surface of the log.
- Next step is to apply a good quality silicon-ized latex caulk (not pure silicon) into the check bringing it out close, but not even, with the surface of the log.
- Now the caulking is skimmed off with your finger or a putty knife being careful to make sure the caulking makes strong contact with the top and bottom of the check.
- Finally, if tape was applied remove it.
Now that you have caulked checks on your house, you need to make this a place that you routinely inspect to make sure that the caulking has not split or cracked. Caulking that has split is the main reason we don't recommend caulking checks under 1/4". Checks less than 1/4" wide move so much as a percentage of their size that they are almost impossible to keep filled. The caulking simply can’t handle this amount of movement.
Filling checks is part of an overall water management plan. Failure to control water is a guarantee of future problems including rotten logs and failure of finishes and chinking. Applying a quality caulk can seal these up-facing cracks and prevent water from penetrating into the log.
For more information on how we handle problematic cracks, contact us.
