I built my log cabin from scratch.
The biggest pain was chinking with mortar between the logs. Single use plastic grocery bags to the rescue. Stuffed between the logs they provided a fillling, weather proof mortar saving foundation for the chinking.
My way of eliminating single use plastic grocery bags is to make them multiple use plastic grocery bags. I always carry a few in my back pocket.
Click here to find some reasons no outdoorsman should be without them.