Keene’s Cement – A gypsum plastering ingredient that, when mixed with finish plaster, produces a dense surface commonly used around showers and bathtubs.

Kerfed Member – Lumber with saw cuts on the underside to permit bending.

Kiln – A heater chamber for drying lumber. 

Kiln-Dried Lumber – Lumber that has been seasoned in a kiln to lower the moisture content to approximately 7%.

Kilowatt Hour – Defined under “Electrical Terms”.

King-Post – The upright member in the center of a simple truss, extending from the apex to the middle of the bottom chord.

Knee Wall – Partitions of varying length used to support roof rafters when the span is so great that additional support is required to stiffen them.

Knot – That portion of a branch or limb embedded in the tree and cut through in the process of lumber manufacture. Knots are classified according to size, form, quality and occurrence.