I live in Northern Michigan. I’ve had full natural sized logs that had surface rot repaired by attaching 1/2 logs to them. The problem is that those half natural various sized logs only get about 4 years before they rot. What type of log should be used? The problem is the lower logs where the snow lays on them for months. I prefer the 1/2 log method being it’s easier than a full log replacement but if I have to do this so often, it may not be the best way. The inner half of the logs are solid.
You may want to go with a treated log. Doesn’t look or match real well, but will not rot for years. other than that, Red Pine would be best. Never White Pine since it rot much quicker. Also, a good quality borate like Shell-guard should be applied before staining to help prevent rot. Anything you can do to prevent the snow and rain against them will help. Do you have rain gutters? Call Ryan at 877-788-56474 for more help.