Chinking is the stuff you put between the logs to keep the weather out. That’s why we like to build an insulated sandwich in the spaces to insure against a Canadian winter barging uninvited into our livingroom and making itself at home. The ideal space to work with is about three inches of height by the thickness of the log, usually about eight inches. Historically we’ve found some ingenious methods that the pioneer builder used to fill the spaces; cedar rails hewn to fit, cedar shingles wedged together, horsehair or stones set in lime and sand mortar, and other natural materials that often did little to insure interior warmth.
Today we like to improve on their ideas of weatherproofing and there are some great products available to do just that. Those little cans of spray foam are just the thing. So much easier to use than that two large canisters we’d haul around that became foam when you pulled the unreliable trigger that messed up in seconds.
So here’s the sequence of events, using our tried and true method. We begin on the exterior, cutting the wire lath in strips that match the height (and a bit more) of the spaces. We tack the wire with large-headed 2” galvanized nails about every 10” to the upper log and the log beneath it, careful to keep the wire edge within the log’s exterior surface. When the weather is right, (and this is important) usually in the spring or fall when it is damp, we trowel on the mortar. We like to use slaked lime in the mix, especially if you’re looking for that nice white chink line. Many do. There are dyes available to add to the mortar if your taste goes to other shades. If the chinking space is large the mortar may have to be applied in two stages. The weight of the mortar may fall otherwise. The mortar must be kept damp for many days. Too much sun would dry out the mortar, leading to cracks later. A light spray of a hose or soaked burlap bags hung on the walls usually suffice.
When the mortar seems stable we go to the interior and spray in the foam insulation. It expands to close up the spaces. Not a whisper, not a gnat can get through. Unnecessary foam excess can be cut off easily with a kitchen knife or serrated scraper. Then the wire mesh is applied over the foam in preparation of the mortar, which should also be kept damp. Before the mortar sets up check for sags, patting them out if necessary. Wiping over the entire length of the chinking with a synthetic sponge gives a nice texture overall. Best wipe off any mortar spill on the logs before it dries.
That’s about it. Maybe a do-it-yourself project. Put the kids to work!