Chinking

Chinking is a material and technique used to seal the gaps between the horizontal logs in log construction, and to seal joints in other timber buildings. The term can refer to both the material itself and the act of applying it. Proper chinking helps reduce air infiltration, water entry, and pest intrusion while allowing for wood movement as the structure expands and contracts.

Traditionally chinking consisted of local, workable mixtures such as clay or mud with sand, straw, or animal hair, sometimes reinforced with moss or plant fibers. Lime putty, cementitious blends, or asphaltic compositions were used in different regions and periods. In modern building, flexible chinking compounds based on acrylic or polyurethane are common, often designed to remain elastic through cycles of freezing and thawing and to shed moisture. Some systems combine a foam backer, a sealant layer, and a finishing coat.

Application typically involves cleaning the gaps, backing the joints if needed, and applying or extruding the chinking material to fill the voids. The material is then shaped and smoothed to create a uniform surface on both the interior and exterior faces. Chinking must accommodate movement of logs and temperature-related changes, so elasticity and proper curing are important. In some designs, chinking is paired with splash protection or weatherproof membranes.

Maintenance includes inspecting for cracks and moisture intrusion, cleaning joints, and replacing deteriorated sections. Chinking is distinct from mortar in masonry and from caulking in modern frame construction, though all serve to seal joints and improve energy efficiency.