Chinking fills the spaces between the logs, keeping out drafts and rain. In early Appalachian log houses, the chinks were thin pieces of wood or stone that were wedged diagonally, like fallen dominoes, into the spaces between the logs. The chinks provided backing for mud or clay or other substances. One of the problems with log houses is that they can be drafty because of the spaces between the logs. In old log houses, chinking often cracked and fell out repeatedly, responding to the movement of the logs, which expand and contract especially when green, and the changes in temperature and humidity. Log house builders have tried many materials and techniques to try to get chinking to stay in place. Charles McRaven’s book, Building & Restoring the Hewn Log House, has a useful discussion of chinking techniques.
For our house, Lewis and his crew will insert metal lath between all the logs. On the exterior, Lewis will use Perma-Chink. When the outside is done, he will begin on the inside by adding a layer of insulation between the logs. Then he will chink the inside with a traditional mortar mix.
Today Lewis began adding mortar over the lath on the exterior of the house. He will cover this layer of mortar with Perma-Chink, which is a modern acrylic latex chinking. Perma-Chink is less likely to crack as the logs settle, contract or expand in different weather conditions. It is capable of expanding lengthwise several times its length. Since our logs are old, Lewis and Kelley do not expect them to move very much, but Lewis finds that Perma-Chink works well to avoid the problem of cracking chinking.
The very high-tech device Lewis is standing on is called a “pump jack scaffold.” Lewis pumps with his foot to raise or lower the board he is standing on. Geez.