Face Side: The side of a piece of wood or timber that shows the best quality.
Fiber Failure: Failure from tension in the lower fibers of a timber.
Flashing: Weatherproofing strips formed from metal, which channel water in a specific way. Step flashing is a series of short flashings that are layered between courses of roofing. Counter flashing is a piece of flashing that covers step flashings if no siding exists, such as at a log wall. Head flashing covers a window or door unit.
Flat Grain: Plain sawn or sawn tangential to the annual rings, as opposed to edge-grain or quarter sawn.
Framing Chisel: A heavy-duty chisel typically with a one-and-one-half to two-inch-wide blade. Designed to be used with a mallet.
Framing Square: Also called a steel square. An L-shaped metal tool used for laying out joinery. It has a body twenty-four inches long and two inches in width, and a tongue sixteen inches long and two inches in width.
Flutes: Hollows or grooves cut longitudinally for ornamental purposes.
Full-Width Notch: A notch on the tension or compression face of a bending member that extends across the full width of the face.
Furring: Any flat piece of lumber used to bring an irregular framing to a flat surface; in particular, a narrow strip of lumber, which is nailed to rafters, studding, and joists as backing.
Gable Roof: A double-sloping roof that forms an A-shape.
Gambrel Roof: A double-pitched roof with the lower slope steeper than the upper slope.
Gas Filled Window: Insulating glass units with a gas other than air in the air space; to decrease the unit's thermal conductivity "U value" (see U value)
General Contractor: A professional who oversees a construction project, including the scheduling, supervision and payment of subcontractors.
Girder: Major timber that spans between sills.
Girt: Major horizontal timber that connects posts.
Glaze: To fit a window frame with glass.
Glulam: An engineered support beam made up of laminations of dimension lumber that have been glued together.
Grain: A term used with reference to the arrangement or direction of the wood elements (spiral grain, cross grain, etc.) and to the relative width of the growth rings (coarse grain, fine grain, etc.) It is also used to designate the angle of the growth rings in relation to the axis of the board (edge grain, flat grain).
Green Lumber: Unseasoned or wet lumber; lumber in which free water still remains within cells; lumber which has a moisture content above the fibre saturation point (approximately 25 to 30%).
Green Wood: Wood freshly cut that is not dried or seasoned.
Grilles: A decorative grid installed on or between glass panes, that does not actually divide the glass.
Gunstock Post: A post wider at the top than the bottom. The wider portion provides more wood for intersecting joinery.
Half Dovetail: A dovetail tapered only on one side.
Half Lap: A joint in which the two timbers are lapped or let-in to each other.
Half-Timbered Frame: An ancient building system in which the space between the timbers is filled with brick, plaster, or wattle and daub, so that the timbers are revealed to the exterior and to the interior of the building. The wattle was a framework of woven withes covered by layers of daub consisting of clay, lime, horsehair, and cow dung.
Halving: The removal of half the depth of two timbers in order that they may cross each other. A half lap.
Hammer Beam: A roof bracket projecting from the top of the wall that supports a roof truss. The design creates a large span with relatively short timbers.
Hand-Peeled: The process of removing the bark and outer layer (cambium) of a log. Hand peeling is usually done using a drawknife, although some companies use machines to achieve a hand-peeled look.
Hardwood: Wood of certain deciduous trees, e.g., oak, maple, ash, etc.
Header: Built-up horizontal member of a home's frame that tops a window or doorway.
Heartwood: The inner layers of wood which in the growing tree have ceased to contain living cells, as opposed to the sapwood, which contains growing cells. Heartwood is generally darker in color than sapwood, though in some species the difference is scarcely perceptible.
Herringbone bracing: a decorative and supporting style of frame, usually at 45° to the upright and horizontal directions of the frame.
Hewn: Cut with an axe or an adze. (also called hand hewn)
Hip: A hip is the angled ridge formed by two adjoining planes.
Hold-Down Rod: A metal rod that provides extra anchorage of the roof system to the logs. These are desirable in high wind areas.
Horizontal Timbers: sill-beams, noggin-pieces, wall-plates.
Hook Pin: Drift pin.
Housed Mortise: A recessed mortise in which bearing is provided for the entire width of the tenoned member.
Housing: The shallow mortise or cavity for receiving the major part of a timber end. Usually coupled with a smaller deep mortise to receive a tenon for typing the joint.
Jamb: The side of a window, door, or other such opening.
Jetty: An upper floor that depends on a cantilever system in which a horizontal beam, the jetty bressummer, on which the wall above rests, projects forward beyond the floor below.
Joinery: The art or craft of connecting timbers using woodworking joints.
Joint: The connection of two or more timbers.
Joists: Small, parallel timbers that complete the floor frame.
Kerf: The groove formed in wood while being sawn or the thickness of the wood removed as sawdust.
Kerfing: Either a series of cuts with a circular saw set at a desired depth to remove a section of wood or the hand-sawing along the shoulder of an assembled joint to improve the fit of the joint.
Keyway: A joint between the footing and foundation wall.
Kiln: A heated chamber for drying lumber.
Kiln-Dried Lumber: Lumber, which has been seasoned in a dry kiln, usually, though not necessarily, to a lower moisture content than that of air seasoned lumber.
King Post: A central, vertical post extending from the bent plate or girt to the junction of the rafters.
Knee Brace: A small timber that is framed diagonally between a post and a beam.
Layout: The drawing of a joint on a timber before it is cut.
Lean-to: A shed section of a building that is framed into the main frame.
Live Load: Weight due to occupancy of building (people, furnishings, etc.).
Load: Weight.
Mallet: A hardwood hammer weighing from one and one-half to two and one-half pounds. Used for driving a chisel.
Maul: Beetle.
Maximum Allowable Fiber Stress in Bending: Safe design standard for fiber stress.
Maximum Allowable Horizontal Shear Stress: Safe design standard for shear stress.
Modulus of Elasticity: A measure of rigidity of a material. The ratio of stress (force per area) to strain (deformation).
Moment: The product of force times distance from which it acts. This causes a beam to bend.
Moment of Inertia: A property that reflects the strength of a timber dependent upon the size and shape of its cross section.
Mortise: A groove or slot into which or through which a tenon is inserted.
- Open mortise - a mortise which has only three sides.
- Stub mortise - a shallow mortise, depth depends on the size of the timber; also a mortise that does not go through the workpiece (as opposed to a "through mortise").
- Through mortise - a mortise which passes entirely through a piece.
- Wedged half-dovetail - a mortise where the back is wider, or taller, than the front, or opening. The space for the wedge initially allows room for the tenon to be inserted, the presence of the wedge, after the tenon has been engaged, prevents its withdrawal.
- Through wedged half-dovetail - a wedged half-dovetail mortise which passes entirely through the piece.