Abutment:
In joinery, the end of one timber touching another. See also BUTT
JOINT.
Adaze:
A handled edge tool (various patterns) with its edge at a right
angle to the handle, used to shape or dress timbers.
Aisle:
Lengthwise space (parallel to the roof ridge) in a building divided
into several such spaces, usually three. Cf. BAY.
Anchor
Beam: Major tie beam joined to H-bent posts, generally
with shouldered, outside-wedged through-tenons.
Arch
Brace: 1. Curved brace. 2. Brace rising from bridge
abutment to support lower chord of truss.
Arris:
The edge along which two adjacent surfaces meet.
Ashlar
Piece: Short vertical strut near the foot of a rafter,
joining it to a sole piece at the top of a masonry wall.
Auger:
A handled edge tool for boring holes in wood.
Backing:
Top surface of a hip or valley rafter, beveled to follow the slopes
of adjacent roof surfaces. The hip backing is thus convex, the valley
backing concave.
Barefaced
Dovetail: A dovetail (see) flared only on one side
and thus suitable for mortising as well as housing. Also half-dovetail
Barefaced
Tenon: A tenon flanked by only one shoulder.
Barge
Board: The board covering the ends of purlins at the
gable end of a roof Also RAKE.
Base
Cruck: Cruck with blades starting as posts and curving
upward to end at the collar beam. Cf CRUCK FRAME.
Bay:
The volume between two bents or cross frames. Cf AISLE.
Beam:
Any substantial horizontal member in a building's frame.
Beetle:
A large wooden mallet typically weighing 15 to 30 lbs. Also COMMANDER,
PERSUADER.
Bending:
Deviation from straight resulting from the application of force.
In a bent member, the concave surface is compressed, the convex
surface is tensioned and the neutral axis is unaffected.
Bent:
1. An assemblage of timbers perpendicular to the ridge, usually
the cross frame of a building, sometimes including rafters, assembled
on the ground and then reared up into position. 2. One of the supporting
frames of a railroad trestle.
Bent (gebent) is a Dutch word for example.
Best
Edge: On a timber to be laid out, the secondary reference
surface adjacent to the best face.
Best
Face: On a timber to be laid out, the primary reference
surface, which will typically receive flooring or wall and roof
sheathing. Not an appearance term.
Bevel:
Any non-orthogonal angle taken through the breadth or depth of the
material; the tool to measure or layout such angles.
Binding
Joist: Transverse floor timber (runs perpendicular
to the ridge) connecting posts and carrying common joists. Cf. BRIDGING
JOIST.
Birdsmouth:
A 90-degree notch cut into the seat of a rafter to fit the corner
of the plate or a step in it.
Blade:
1. In a scarf joint, the termination of one half of the joint so
as to lap under the beginning of the other half 2. In a cruck frame,
one half of the cruck.
Bolt-O'-Lightning:
Scarf form with many abutments, whose jagged interface line resembles
its eponym; used in heavy work.
Boring
Machine: . A hand-cranked device with gears that drive
an auger bit, used to bore large holes, as in roughing out a mortise.
Bow:
Deviation from straight in the length of a timber. Also SWEEP. See
also CROOK and CROWN.
Boxed
Heart Timber: Timber whose section includes the heart
of the tree. Since checks will not cross the heart, such a timber
can never split completely. Cf FOHC.
Box
Frame: Construction in which roof trusses are carried
by a self-supporting structure of posts, tie beams and wall plates.
Cf CRUCK FRAME.
Brace:
Any diagonal timber (permanent or temporary) that resists distortion
of a frame. See also KNEE BRACE. BRACKET. Block tenoned or pegged
to one timber to support another. Also cleat.
Breadth:
See WIDTH.
Bridging
Joist: Intermediate floor beam connecting one cross
frame to another and carrying the inner ends of common joists. See
also SUMMER BEAM. Cf BINDING JOIST.
Bridle:
1. An open mortise and tenon end joint, such as at a rafter peak
or sill corner, with one end of the mortise open (see TONGUE AND
FORK). 2. An open mortise and tenon joint between the top of a post
(the bridle) and a passing beam reduced in section to form the tenon.
Broadaxe:
Wide-bladed axe with its edge usually beveled only on one side,
and fitted with an offset handle for knuckle clearance. Used to
hew timbers from logs or for similar shaping work.
Buckling:
Irreversible bending of a timber as a result of a compressive force
along its axis.
Builder's
Level: A rotating telescope set on a tripod and used
for leveling a foundation or sill timbers.
Butt:
1. The end of a log that in the living tree stood at the ground;
generally, the larger end. 2. The end of a timber cut at right angles
to its length.
Butt
Joint: An abutment (see) of two timbers withoUt penetration,
kept in place by gravity or other timbers, or ironwork.
Buttress:
A reinforcing mass, typically masonry, built against a wall to counteract
the thrust of an arch.
Camber:
Hewn, sawn, natural or deliberately bent upward sweep in a beam
or in its top surface, often incorporated into the lower chords
of timber trusses, to increase stiffness (especially in bridges)
or to obtain aesthetic effects in the space below. See also CRANK.
Cantilever
Beam: A projecting timber unsupported at one end.
Carrying
Sticks: Sticks placed under a timber to provide easy
handholds for carrying.
Chain
Mortiser: Jigged power tool with chain-mounted cutters
that plunge into the face of a timber to cut a mortise, fitted with
a depth stop and other controls.
Chamfer:
A bevel cut at the long arris of a timber, which may be run right
through or decoratively stopped before the ends; a bevel at the
leading arrises of a tenon, to ease assembly.
Chase
Mortise: 1. A lengthened mortise for swing-insertion
of a tenoned member otherwise impossible to insert in an existing
assembly, such as a brace or a joist added after assembly of main
members. See also PULLEY MORTISE. 2. A mortise with one end angled
to follow the slope of a member such as a brace.
Check:
Separation of wood fibers along the rays, caused by the tension
of differential radial and tangential shrinkage or by surface fibers
of a timber drying first and attempting to shrink around an incompressible,
still-wet center.
Check
Brace: A short, low-angle brace fitted behind a principal
post in a bridge truss as reinforcement. It transfers back to a
housing in the chord the horizontal component of the main brace
load arriving on the front of the post. Also kicker (M.
Graton, 1972).
Cheek:
The broad surface of a tenon; the corresponding surface of a mortise.
The tenon shoulder is usually square to its cheek.
Chord:
In a truss, the major uppermost member (top chord) or lowermost
member (bottom chord). In a roof truss, the principal rafters serve
as top chords, the tie beam as bottom chord.
Clasped
Purlin: A purlin fitted under the common rafters (the
principal rafter is reduced to match) and over the collar beam.
Cog:
Recess in one timber to accept full cross-section of the end of
another timber; notch. See also HOUSING.
Collar
Beam: Horizontal member fitted between a pair of opposed
rafters, used, depending upon position, to prevent sagging or spreading
of the rafters. Often improperly called collar tie.
Collar
Purlin: In a roof frame, the central longitudinal
beam running under the collar beams and usually supported by crown
posts.
Commander:
See BEETLE.
Common
Purlin: In a roof frame, lengthwise member, regularly
spaced in sets, connecting principal rafters and carrying the roof
sheathing. See also PRINCIPAL PURLIN.
Common
Rafter: Inclined member, regularly spaced in sets,
that supports the roof sheathing. See also PRINCIPAL RAFTER. COMPOUND
JOINERY. A connection whose timbers are cut at non-orthogonal angles
on both face and edge, typically found in hip and valley roofs.
Compound
Roof: Hips (outside corners) or valleys (inside corners)
formed where two adjacent roofs join at an angle.
Compression:
The state of stress in which particles of material tend to be pushed
together.
Corbel:
A block protruding from a wall to support the springing point of
a masonry arch or a roof or floor member.
Corner
Chisel: A chisel with two equal cutting edges forged
at 90 degrees, struck with a mallet to clean out the corners of
a mortise.
Crab:
In steeple work, an eight-armed flat roof frame that sits upon the
octagon stage of a steeple, supporting the next octagon.
Crank:
A sharp change of angle in a timber, usually in a collar or tie
beam higher at the center than at the ends on both upper and lower
surfaces. See also CAMBER.
Cribbing:
Stack of crisscrossed short timbers used for temporary support of
a structure or timbers being worked on.
Crook:
Deviation from straight in the length of a timber. In a plank, crook
is curvature of the width, bow (see) is curvature of the thickness;
in a squarish timber, the two are indeterminate.
Crosscut
Saw: Saw whose teeth are sharpened to a point and
set outward to cut across the wood fibers by severing to left and
right, so that the waste between falls out as dust. Cf. RIP SAW
Cross
frame: See BENT. However, traditional cross frames
do not include rafters.
Crossgrain:
Grain not parallel to the long axis of a timber. The ultimate strength
of a timber is greatly dependent on the slope of its grain. Also
DIAGONAL GRAIN.
Crown:
Curvature in a timber's length placed upward in spanning members
where the load will tend to straighten it.
Crown
Post: Central post of a roof truss that connects the
beam to the collar or to the collar purlin.
Cruck
Frame: Early timber frame type with each cross frame
made up of two opposed and collared timbers, usually curved, se
up as an arch or A-frame that rises from the ground or a short foundation.
Each half of a cruck is called a blade, and a matched pair of blades
is often cut from the same tree. Cf. BOX FRAME.
Crushing:
Permanent deformation resulting from compression
Dap:
To house in (usually) a beam; the housing (see) itself.
Dead
Load: Weight of building (roof, floors, walls, etc.).
Deflection: Movement of structure under load.
Depth: 1. The vertical dimension of a beam or rafter. 2. The sectional
dimension of a post measured perpendicular to the wall otherwise,
the larger dimension of a post.
Diagonal
Grain: Also sloped grain. See CROSSGRAIN.
Dimension
Lumber: Planed timber sold according to it nominal
size, usually less than 6 in. thick.
Dormer:
Aperture or window of variable shape rising upright from the surface
of a roof and having its own roof. According to it extent and form,
a dormer may be termed eyebrow, doghouse, roundhead, shed or running.
Double
Tenon: Two tenons cut in line on the end of a wide
or deep member. A triple tenon is possible. Cf. TWIN TENON.
Dovetail:
A central or lap tenon shaped like a dove's spread tail to fit a
corresponding notch. See also BAREFACED DOVETAIL.
Dragon
Beam: A horizontal timber bisecting the angle formed
by two wall plates and used to carry the foot of a hip rafter or
the inner ends of joists from the adjacent walls, or both.
Drawbone:
Traditional fastening technique in which the peg hole in the tenon
is deliberately offset from the peg hole in the mortise to draw
a joint tight when assembled and fastened with a tapered pin. The
proper offset varies with species and scale.
Drawknife:
A large knife blade with bent tanged handles a each end so that
the knife can be pulled with both hands toward the user; for chamfering,
shaving pegs and shingles and general trimming.
Drift
Pin: Tapered iron pin with enlarged head used to bring
joints home and hold them temporarily during assembly, to be removed
and replaced by a permanent wooden pin. Also hook pin.
Drop:
In general, any ornamental pendant; in particular, the square-turned
or carved termination to the lower end of a second story post in
a framed floor overhang.
Eave,
Eaves: The drip edge of a roof, often overhanging
the wall.
Edge-Halved:
A lengthwise timber joint divided through its thickness; a class
of scarf joints. Cf. FACE-HALVED.
Extreme
Fiber Stress: Maximum compression in the can cave
edge and tension in the convex edge of a member in bending without
failure.
Fascia:
Generally, a face board to cover the exposed ends of joist or rafters.
In neo-Classical trim, the horizontal band in the comic assembly,
set plumb to cover the edge of the soffit.
Face-Halved:
A lengthwise timber joint divided through it width; a class of scarf
joints. Cf. EDGE-HALVED.
Fish,
Fishplate: Reinforcing member applied over a break
in a timber or an end joint between two timbers; usually applied
in pairs and bolted right through.
Flying
Plate: In a framed overhang, a beam set outside the
wall plane and forming a solid base for the cornice elements and
some times for the feet of common rafters; it can be continuous
or interrupted (by tie beams) according to the framing system. Cf.
PLATE
FOHC:
Free of heart center. Timber sawn to exclude the heart can in theory
be seasoned without checking.
Footing:
Sub-foundation.
Framing
Chisel: (US). A long, rectangular-section heavy-duty
socket-chisel typically 1 1/2 in. or 2 in. wide, handled for striking.
Framing
Square: L-shaped metal graduated measuring tool with
legs fixed at 90 degrees, used for layout and checking of angular
lines. Most framing squares have a body 24 in. long by 2 in. wide
and a tongue 16 in. long by 1 Y2 in. wide. Also STEEL SQUARE, RAFTER
SQUARE.
Free
Tenon: A tenon cut as a separate piece and used,
via appropriate mortises, to join two timbers face to face, end
to end or end to face. See also SPLINE.
Froe: A stout, flat-bladed, handled tool for cleaving pegstock
as well as shingles, clapboards or sections for furniture.
Gable
Roof: A double-sloping roof that forms an inverted
V.
Gain: Sizing (see) reduction at timber surface in joinery
area; any shallow housing, as for a hinge. Cf HOUSING.
Gambrel
Roof: A double-pitched, double-sloping roof with
the lower slopes steeper than the upper slopes; resembles the gable
roof but with each leg of the inverted V broken into two pitches.
Gin
Pole: A lifting device composed of a single pole,
stayed by guy lines, from which lifting tackle is hung.
Girder: Major timber spanning between sills to carry floor joists.
Girding
Beam: See BINDING JOIST.
Girt: Horizontal timber joining wall posts at a level somewhere between
sill and plate. A wall girt runs parallel to the ridge, a bent girt
perpendicular; either can support the edge of a floor frame.
Grain: The pattern of growth rings, rays and other structUral
elements in wood made visible by conversion from the tree.
Green
Wood: Wood freshly cut, not dried or seasoned.
Groundsill: Sill, originally laid directly on the ground.
Gunstock
Post: A post deeper at the top to provide more wood
for intersecting joinery, and usually obtained by inverting the
timber from its grown position to take advantage of butt taper or
swell. Cf JOWL.
Half
Dovetail: See BAREFACED DOVETAIL.
Half
Lap: An end joint or a crossing (the latter called
a halving), in which two timbers are let in to each other to half
their depths.
Half-Timbered: 1. An evolved building type in which wall timbers are spaced out
(cf STAVE CONSTRUCTION), to be filled in with other materials. 2.
Closely studded or otherwise elaborated versions of the type. See
NOGGING and WATTLE AND DAUB. HALVING. See HALF LAP.
Hammer
Beam: A roof bracket consisting of an interrupted
tie beam projecting from the top of a wall and supporting a roof
truss. A complete hammer beam roof frame permits a large roof span
made of relatively short timbers.
Hardwood: Wood of certain deciduous trees, e.g., oak, beech, ash and the like.
Cf SOFTWOOD.
Haunch,
Haunched Tenon: On a tenon, the part--square or diminished
in outline-that would otherwise be removed to preserve the relish
of a mortise cut quite near the end of a timber. The haunch helps
preserve alignment of the members without unduly weakening the end
of the mortise.
H-Bent: Crossframe made up of floor-to-roof posts connected by a heavy,
braced tie beam, usually enclosing the taller central aisle of a
Dutch or other three-aisle barn.
Header: 1. Floor member running across the joists at an opening, as for
a staircase, and supporting the ends of cut joists. 2. Wall member
bridging the opening for a door or window and carrying any cut studs.
3. Roof member bridging the opening for a chimney, dormer or skylight
and carrying any cut rafters.
Heartwood: The inner, nonliving part of the tree, as a rule
the more durable portion.
Hew: Shape wood with an axe, usually to convert a log
to a timber.
Hip
Rafter: In a roof frame, the rafter that follows
the line of the hip, typically backed to follow the slopes of the
adjacent roofs.
Hip
Roof: A compound roof occurring where two roof slopes
meet over an outside corner. Cf. VALLEY ROOF.
Hog: Lengthwise deformation of a timber supported in the
middle and (over)loaded at its ends. Cf. SAG.
Hollow
Chisel Mortiser: Jigged power tool with fitted auger
bit inside a square hollow chisel that plunges into the face of
a timber to cut a mortise, fitted with depth stop and other controls.
Horizontal
Shear: Shear along the grain resulting a beam is
loaded in bending.
Housing: A shallow mortise or cavity to receive the full section of a timber
end for load bearing. Often but not always combined with a standard
mortise to add bearing area and secure the connection via the tenon.
Cf GAIN. See also COG and DAP.
Hundegger: Proprietary name for computer-controlled industrial
joinery machine designed to handle large timbers.
Infill: 1. Insulation placed inside timber-framed walls (see NOGGING and
WATTLE AND DAUB). 2. Studding placed between major posts to support
interior and exterior finish.
Jack
Rafter: A roof framing member that lies in the common
pitch and terminates at the hip or valley rafter. In a valley system,
the jack runs from the ridge down to the valley; in a hip system
it runs from the eave up to the hip. In general, any rafter shortened
from its full run between ridge and plate.
Jamb: Side of any opening such as a door or window.
Jetty: Cantilevered overhang of an upper story.
Joinery: The work of connecting timbers using woodwork joints; the joints
themselves.
Joint: The connection of two or more timbers; to make one.
Joist: Relatively small timber, usually spaced regularly
in sets to support a floor or ceiling.
Jowl: Local step or flare near end of post or beam to ac date joinery.
Cf GUNSTOCK POST.
Juggling: In hewing, striking a log crosswise at wide intervals and then splitting
off the chunks in between, to remove the bulk of the waste before
broadaxe work. Also SCORING.
Kerf: The space left by the passage of a saw blade.
Kerfing: . 1. Making a series of shallow sawcuts to hasten
removal of a section of wood. 2. Sawing along the abutments of an
assembled joint to improve the fit.
Key: Small element, usually wedge shaped, used to lock a joint or, if
a shear key, to prevent sliding of one member over another.
Kingpost: In a truss, the central, vertical member extending from the tie
beam (or lower chord) to the peak and receiving upper ends of the
rafters (or upper chords). Cf QUEENPOST
Knee: Alternative term for brace, but often implying a naturally curved
piece, usually taken from the base-swell of certain trees that presents
long grain to both timbers being braced. Knees are termed hanging
(if beneath the beam), standing (if above the beam) and lodging
or lying (if bracing beam to beam).
Knee
Brace: A relatively small, short timber framed diagonally
between two members at right angles to stiffen their connection.
Lap
Joint: Similar to the half-lap joint, but the parts
are not necessarily housed to half their depths.
Layout: The drawing of a joint on a timber before it is cut; the arrangement
of timbers into a predetermined pattern for marking.
Lean-To: A shed-roofed section of a building, often an addition, joined into
the main frame. See also OUTSHOT.
Ledge
or Ledger: Band of timber fastened to or let into
the face of studs or posts to support the outer ends of floor joists.
Also RIBBAND.
Lintel: Horizontal beam over a door or window opening. Also
HEADER.
Live
Load: All load other than the permanent weight of
a structure including people, furnishings, snow, wind, earthquake,
etc. (Cf. DEAD LOAD.)
Load: Force imposed on a structure.
Mallet: A hammer of wood, rawhide, steel or synthetic material,
weighing generally between 24 and 40 oz., and used to drive a framing
closed.
Marriage
marks: are the numbers (usually Roman) which are carved
into beams near the mortises and tenons that tell the carpenter
what fits into what (i.e. insert tab "A" into slot "B,"
or more to the point, tenon "IV" into mortise "IV").
They were particularly necessary for early buildings where every
joint was custom made and no parts were interchangeable.
Mast
: In framed spires, a central timber that anchors
the spire rafters at their apices and moves the center of gravity
of the spire inward and down. Masts often exceed 45 ft. and may
be pendant, compressing the rafters, or clasped by partner timbers
(nautical tradition) to stiffen the spire.
Miter: Equal division of the angle formed by two intersecting members.
Modulus
of Elasticity: A measure of stiffness of a material.
The ratio of stress (force per unit area) to strain (deformation).
Moment: A load that imparts torque or rotation, quantified as the product
of a force times the distance over which it acts.
Moment
of Inertia: A measure of the resistance of a body
to angular acceleration about a given axis. Moment of inertia is
the section property used to gauge the stiffness of a beam in bending. For
rectangular members of breadth b and depth d, the moment of inertia
taken through the centroid (center of mass) of the section is quantified
by the formula I = bd3 divided by 12.
Mortise: In general, a rectangular cavity into which a tenon (or another
object such as a lock) may be inserted.
Mortise
and Tenon Joint: The end of one timber, usually reduced
in section' to form the tenon, inserted into a corresponding cavity,
the mortise, in the face of another timber, and most often pinned
across, though sometimes otherwise secured.
Mud
and Stud (UK): 1. Late framing method using relatively
few and light framing members infilled with wattle and daub. 2.
Notorious timber framers' pub in the East Midlands.
Mullion: Vertical division in window opening.
Nogging: Infill in early framed walls, often brick. See also WATTLE AND DAUB
and HALF-TIMBERED.
Nominal
Size: Sawn or hewn timber dimensions before sizing;
actual dimensions may be larger or smaller than nominal.
Notched
Lap Joint: . Lap joint with interference surface
cut to prevent withdrawal of the tenon, found in very early braces.
Outshot: Lean-to (see) area added to a building, usually an
aisle.
Overhang: Projection of second story beyond the first, or projection
of roof over wall.
Packing
Piece: 1. Short piece of material used to fill the
empty space in a mortise previously elongated to allow insertion
of a tenoned member into an existing assembly. 2. In cruck framing,
the cleat set on the back of a cruck blade to carry a purlin.
Pargeting: External plastering.
Passing
Brace: A long brace half-lapped over other timbers,
sometimes running from plate to sill (Cecil Hewett, 1962).
Peavey: A pointed tool with long stout handle and forged
side hook, used to roll logs or heavy timbers.
Peg: A wooden pip typically 3/4-in. dia. and larger, usually
of oak or other tough hardwood, formerly riven and shaved, now usually
turned, and used to fasten timber joints, particularly the mortise
and tenon joint. Bridge builders distinguish tapered pegs from cylindrical
pins: the latter are used particularly at connections stressed in
shear (see PIN 2).
Pentice: Narrow roof projecting from a wall over a door or window to protect
it from the effects of the weather.
Persuader: See BEETLE.
Pike
Pole: A long pole, pointed with a sharpened spike,
used to raise frames. These tools were known as early as the 15th
century, when they were called butters.
Pin: 1. A short shaft of tough hardwood, often tapered,
used to draw together and fasten the traditional mortise and tenon
joint in timber framing. See PEG. 2. A pin of uniform diameter,
usually 1 or 2 in., used to transfix timber, join members or resist
flexure when the goal is to maximize the uniform bearing area between
timber and fastener, notably in bridge lattice-truss work.
Plate: (US). In normal position, the most important longitudinal
timber in a frame. It ties the bents together at their tops and
simultaneously stiffens and connects the wall and roof planes while
providing a base for the rafters. Also top plate, wall plate. Cf.
FLYING PLATE.
Plate: (UK). The sill or the subsill; the sole plate.
Plumb: Vertical; perpendicular to the ground.
Post: Vertical or upright supporting timber. See STORY
POST and PRICK POST. Cf. BEAM.
Post
and Beam: 1. Any structural system made up primarily
of vertical and horizontal members. 2. Such a system in which floor
and roof loads are carried by principal timbers butted together
and fastened with structural hardware. 3. A structural system of
heavy timbers connected by woodwork joints. See TIMBER FRAME
Prick
Post: A post of single-story height.
Principal
Purlin: In a roof frame, lengthwise timber connecting
principal rafters and carrying common rafters. See also CLASPED
PURLIN, COMMON PURLIN, PURLIN and RIDGE PURLIN.
Principal
Rafter: In a roof frame, a large inclined timber carrying
a substructure of purlins and common rafters, usually but not always
placed over a principal post.
Pulley
Mortise: 1. Long mortise found at the lower edges
of the lower chords of roof trusses, where ceiling joists were evidently
swung in after erection of the trusses. See CHASE MORTISE.
Purlin: Any longitudinal member in a roof frame lying in
or parallel to the roof plane.
Purlin
Plate: In a roof frame, a longitudinal continuous
timber used to support common rafters near the center of their span
and itself supported by posts or struts.
Pythogorean
Theorem: In a right triangle, the theorem that the
sum of the squares of the sides is equal to the square of hypotenuse
(a2 + b2 = C2). Used to calculate rafter, knee-brace and other lengths.
Queenpost: In a truss, one of a symmetrically placed pair of
vertical members standing on the tie beam or lower chord and separated
at their upper ends by a straining beam. In a barn, queen-posts
may be full height and connect to rafters, the collar bean purlin
plates. C£ KINGPOST.
Rabbet: An open (one-sided) groove cut at an arris.
Rabbet
Plane: A handplane with cutting edge exposed completely
across the sale, and thus able to cut up to an inside corner; used
to trim tenon cheeks and shoulders, to level material across the
grain and to form or trim rabbets.
Rack: The action of straining or winching a framework to
bring! it into square or plumb; the opposite action by a force of
nature.
Rafter: . In a roof frame, any inclined member spanning any part of the
distance from eave to peak. See COMMON RAFTER, PRINCIPAL RAFTER
and JACK RAFTER.
Rafter
Foot: The lower end of a rafter, usually framed into a plate or a tie
beam, rarely into a post.
Rafter
Peak: The point where the tops of opposed rafters
would meet if mitred (see). A series of such points forms a ridge.
Rafter
Square: See FRAMING SQUARE.
Raising
(A Frame): Erecting the bents, roof trusses and other
subassemblies of a frame and fastening them. Also REARING
Rake: In a gable or gambrel roof, the edge of the roof
as seen at the gable end. Also BARGE BOARD.
Raking
Strut: . In a roof truss, an inclined member fitted
between the tie beam and the principal rafter.
Reaction: A force pushing back in response to a load.
Rearing
(A Frame): UK term equivalent to RAISING.
Relish: 1. In the case of a mortise cut quite near the end of a timber,
material the width and depth of the mortise remaining between the
mortise-end and the end of the timber; in a tenon, material between
the peg hole and the end of the tenon, equal in cross-section to
the path of the peg through the tenon.
Reversed
Assembly: (UK). For a timber frame with continuous
top plate, raising procedure in which the crossframes or bents including
tie beams are raised first and the top plates are laid last. Traditional
assembly first raises the sidewalls including the plates and lays
the tie beams over the plates, as for the English tying joint (Cecil
Hewett, 1962). American frames with dropped tie beams are raised
by "reversed assembly."
Ribband: See LEDGE.
Ridge
(Ridge Piece, Ridge Tree): . In a roof frame, the
continuous longitudinal timber at the peak of the roof to which
the rafters and sometimes wind braces are attached; ridges are often
five-sided or otherwise non-orthogonal in section to allow square
connections to the rafter ends when the roof peak is not square.
Ridge
Purlin: In a roof frame, a ridge member, continuous
or interrupted by rafter apices, lying in notches or trenches on
one side of the roof; if continuous, sometimes itself trenched where
it crosses a principal rafter.
Rip
Saw: Saw whose teeth are designed to cut parallel
to the wood fibers, each tooth a small chisel to shave off lengthwise
a short bundle of fibers that falls out as stringy waste; the teeth
are set left and right merely for clearance. Cf. CROSSCUT SAW.
Rive: To split wood along the grain, thus avoiding any
slope of grain, for maximum strength in a given cross-section; pegs,
ladder rungs and chair parts were formerly riven and shaved.
Roof
Pitch: Inclination of a roof to the horizontal, usually
given as inches of rise per foot of run. For example, a roof inclined
at 45 degrees has 12 inches of rise for each foot of run and is
therefore called a "twelve-pitch" roof.
Roof
Truss: See TRUSS.
Router: A hand or power tool designed to produce or to level grooves and
housings along and across the grain; the power tool can also be
used as a molding plane.
Sag: Lengthwise deformation of a timber supported at its
ends and (over) loaded at its middle. Cf. HOG.
Sally: Pointed end of a scarf-half.
Scantling: 1. The cross-section of a timber, as found in a table of scantlings,
together with length. 2. Any small piece of wood.
Scarf: To join two equal-section timbers in their length to make a longer
beam; the joint so used. There are many variations in the form of
scarf joints, such as bladed, bridled, or stop-splayed.
Schnafp: Slang for an inch and a half.
Scoring: See JUGGLING.
Scribe: In general, to mark a timber by scratching a line
with a sharp instrument; specifically, to use dividers to transfer
a profile to be cur-often enough irregular-from one surface to another.
Scribe
Rule: General term for layout systems where each
timber is custom-mated to its neighbors. The process requires setting
out all the timbers for a given assembly in a framing yard or on
a floor, positioned relatively as they will ultimately rest in the
building. Cf. SQUARE RULE.
Seasoned
Wood: Wood dried over time to equilibrium moisture
content with its atmosphere.
Section
Modulus: The section property used to quantify the
strength of a beam in bending; for rectangular sections, given asS=bd2+6.
Shake: Separation of the growth rings in a timber, a structural
defect normally developed during the growth of the tree.
Shear: State of stress wherein particles of material tend
to slide relative to each other; the force inducing such stress.
Vertical (crossgrain) shear loads also impart horizontal (long-grain)
shear stress.
Shear
Block: Wood block dapped (let in) partially to adjoining
parallel laminae in a built-up chord, designed to resist shear between
the two members or to transfer load around a discontinuity such
as a scarf, and properly oriented parallel to the grain, so that
shear block end grain bears upon chord end grain.
Shear
Key: Wood block oriented perpendicular to (across)
the grain. Easier to assemble, and tightenable if wedge-shaped,
but not so resistant to compression as a shear block.
Sheathing: . A covering of rough boards or sheet goods on exterior
walls or roofs, usually itself covered by an additional weatherproof
layer of material.
Shed
Roof: A monoplanar roof sloping in one direction.
Shoulder: In a mortise and tenon joint, the element of the tenoned member
perpendicular to the tenon cheek, and which lies against the face
of the mortised member; there can be as few as one and as many as
four shoulders on the tenoned member.
Shrinkage: Reduction in section and length of a timber as it
dries. Sectional shrinkage is analyzed into tangential (shortening
along the rings) and radial (shortening along the rays).
Sill: Horizontal timber that rests upon the foundation
and links the posts in a frame; usually fastened to the foundation.
Sizing: Planing hewn or roughsawn timber to uniform section,
by hand locally at the joints, or by machine for the whole timber.
Slick: . A large, long, heavy chisel with a blade as much
as 4 in. wide, fitted with a handle meant to be gripped with both
hands, used for trimming and surfacing of all kinds.
Soffit: 1. In general, the underside. 2. In neo-Classical
trim, the cornice element set level and joined to the fascia to
form a band under the edge of the eaves. 3. The trim piece covering
the undersides of overhanging rafters for a roof without cornice.
Soffit
Tenon: A horizontal tenon with lower cheek coplanar
with the lower surface of its beam.
Softwood: The wood of conifers or evergreens, e.g. pine, spruce,
Douglas fir and the like. Cf. HARDWOOD.
Sole
Piece: Short beam at top of masonry wall to carry
the foot of the rafter and the ashlar piece; a sort of interrupted
tie-beam for intermediate roof crossframes.
Sole
Plate: (UK). Sill.
Span: In a roof frame, the horizontal distance covered
by a rafter; in a beam, the unsupported distance from support to
support.
Spandrel: The triangular space between a knee brace or arch
brace and its adjoining members.
Spiral
Grain: In the log, the disposition of the fibers
twisted like a corkscrew around the pith of the tree (and normally
visible in the bark); in the timber, distinctly sloped grain as
displayed by the direction of the rays. Such timbers tend to twist
as they dry and are weaker in ultimate bending than straight-grained
examples.
Splay: 1. In a vertical member, divergence from upright.
2. In a scarf joint, a cut through the depth or breadth of the timber
not parallel to the original surface.
Spline: . 1. A relatively thin piece of material fitted to
full-length grooves in the edges of planks, used for alignment and
load sharing; a feather. 2. A stout piece of material, comparable
in section to a tenon, used particularly to join beams to posts
in three-way and four-way joints where individual mortises cut for
each entering tenon would weaken the post fatally. See also FREE
TENON.
Split: Complete separation of wood fibers, normally on a
ray plane. See also CHECK.
Spokeshave: An extremely short plane with wing handles in line
with the edge of the blade. Pushed or pulled, it is used for forming
and finishing curved surfaces.
Spur: 1. The short tie that connects a cruck blade to the
outside wall post or plate. See CRUCK FRAME.
Square: At an angle of 90 degrees; a measuring tool so angled.
Square
Rule: Layout system in which a smaller, perfect timber
is envisioned within a rough outer timber; joints are cut to this
inner timber. Many timbers in a square rule frame are interchangeable.
Squaring
Off: Cutting off one end of a timber so that the
cut gives a plane surface perpendicular to the length; helpful for
layout.
Squint: In a scarf joint, an abutment angled at other than
square.
Stave
Construction: Ancient wall method of solid posts.
Steel
Square: See FRAMING SQUARE.
Sticker: Spacer used between stacked timbers or boards to
provide air circulation and between stacked bents for strap clearance.
Stop: See CHAMFER.
Story
Pole: A slender stick marked with important intervals,
for repeated transfer in frame, finish or individual timber layout.
Story
Post: A wall post that rises through more than one
story.
Straining
Beam: The topmost horizontal timber joining the upper
ends of queen posts in a truss or in a roof frame.
Stress-Skin
Panel: A sandwich of two layers of sheet goods enclosing
and bonded to a core of framing lumber.
Structural
Insulated Panel: A sandwich of two layers of sheet
goods enclosing and bonded to a core of thermal insulation.
Strut: An axially loaded minor member in a truss or frame.
Stub
Tenon: Abbreviated tenon designed for location only.
Stud: Subsidiary vertical member in a framed wall or partition.
Summer
Beam: Major timber spanning between other floor timbers
to support common joists. See BRIDGING JOIST.
Sweep: See BOW.
Table: 1. In a scarf joint, the raised portion of each scarf-half,
designed to interfere once assembled and so prevent withdrawal in
the length. 2. The broad surface of a vertical housing.
Teazle
Tenon: In the English tying joint, the tenon cut
at the top of the post that engages the underside of the tie beam.
Telescoping
Framing: Steeple framing, concealed from the outside,
that lodges the bottom timbers of any given stage several feet within
the frame of the stage below, contributing stability.
Template: A full-size pattern of thin material, used for laying
out and checking joints and other purposes.
Tenon: The end of a timber, reduced in section and flanked by one or more
resulting shoulders.
Tension: The state of stress in which particles of material tend to be pulled
apart.
Thickness: See DEPTH.
Through
Tenon: A tenon that passes right through the timber
it joins; it may be cut off flush or it may extend past the outside
face of the mortised member to be wedged or locked in place by one
of several means.
Tie
Beam: An important horizontal transverse frame member
that resists the tendency of the roof to spread the walls. The tie
beam may be found at the top of the walls, where it is able to receive
the thrust of the rafters directly, or it may be found as much as
several feet lower down the walls, where it joins principal posts
in tension connections.
Timber: A large squared or dressed piece of wood ready for fashioning as
one member of a structure.
Timber
Frame: A frame of large timbers connected by structural
woodwork joints and supporting small timbers to which roof, walls,
and floors are fastened. Sometimes called a braced fame. Cf POST
AND BEAM 2.
Tongue
and Fork: An end joint in which one timber has the
shape of a two-tine fork and the other a central tongue that fits
between the tines; usually found at rafter peaks. See also BRIDLE.
Trait
de Jupiter: See BOLT-O'-LIGHTNING.
Trench: Crossgrain open housing cut less than half the depth of the timber,
to receive any crossing lapped timber.
Trimmer: Floor member running with the joists at an opening,
as for a staircase, and carrying the end of the header (see).
Trunnel: A peg. Sometimes refers to an extra-large peg.
Truss: A network of timbers forming a rigid support structure;
ideally, all members of the truss behave in either compression or
tension, none in bending. Trusses are used to span distances impractical
for solid members, or to support unusual loads.
Tusk
Tenon: 1. Horizontal through-tenon with outside-wedge
(the tusk) applied vertically (Hewett, 1980). 2. Horizontal blind
tenon with square buttress (the tusk) between lower cheek and shoulder
(Newlands, 1854; Alcock, 1996). 3. Horizontal blind tenon with diminished
buttress (the tusk) between upper cheek and shoulder (Moxon, 1680),
called by Hewett and Alcock (1996) a diminished shoulder tenon, and by Levin (1980) an entrant shoulder tenon. This
buttress is sometimes called a diminished haunch because of its
resemblance in profile to that of a diminished-haunch tenon. However,
the latter tenon is used to make a corner joint, whereas the tusk
tenon is used to connect the end of one beam to the face of another.
Twin
Tenon: Paired tenons cut side by side and used to
strengthen connections in large timbers. Cf. DOUBLE TENON.
Twist: Deviation from plane in the surface of a timber. The bane of the
woodworker. If the twist is the result of released growth stresses
in the tree (see SPIRAL GRAIN), rather than poor conversion, all
surfaces of the timber will be twisted. Also WIND.
Upper
Face: (UK). Best face, used for marking out.
Valley
Roof: A compound roof occurring where two roof slopes
meet over an inside corner. Cf. HIP ROOF.
Vernacular
Architecture: is the architecture of the ordinary
as opposed to the extraordinary, the common as opposed to the elite.
Instead of castles and cathedrals, vernacular architecture focuses
on simple farmhouses and barns, instead of the skyscraper or the
mansion, its focus is the general store or the humble tenement.
Vernacular architecture is about the everyday buildings in which
everyday people lived and worked.
Vernacular
Architecture is the architecture of the ordinary as
opposed to the extraordinary, the common as opposed to the elite.
Instead of castles and cathedrals, vernacular architecture focuses
on simple farmhouses and barns, instead of the skyscraper or the
mansion, its focus is the general store or the humble tenement.
Vernacular architecture is about the everyday buildings in which
everyday people lived and worked.
Walking Beams: Two parallel beams laid on the ground upon which timbers may be
moved with a pivoting action.
Wane: Nature's chamfer; the rounded edges of a timber squared from an
undersized log. Adjective waney.
Warp: Deviation from flatness across the grain. If concave, also called
cup. Timber surfaces typically warp as if to return to the log.
Wattle
and Daub: A framework of woven withes covered b) layers
of daub mixed of clay, lime, horsehair and cow dung, used to fill
openings between studs in early timber frames.
Width: The horizontal dimension of a beam as viewed in place breadth. Cf
DEPTH. Indeterminate for interior posts.
Wind
Brace: A brace lying in the plane of the roof, usually
running from a principal rafter to, a ridge or purlin.
Wind,
Winding: See TWIST.
Winding
Sticks: Matched pair of perfectly straight sticks
laid across a timber at some interval (usually the full length)
and sighted over their top edges to reveal twist in the timber surface.
If the sticks are parallel, the surface is free of twist.
- -by
WILL BEEMER AND KEN ROWER
Published
sources consulted for this beginner's glossary include Recording
Timber-Framed Buildings (Nat Alcock), Building the Timber
Frame House (Tedd Benson), Build a Classic Timber Frame
House (Jack A Sobon), The Timber Framers Workshop (Steve Chappell), The Frame, Houses of Massachusetts Bay (Abbott Cummings), English Historic Carpentry (Cecil Hewett), Discovering Timber-Framed Building (Richard Harris), Mechanick
Exercises (Joseph Moxon) and The Carpenters Assistant
(James Newlands). Ed Levin (engineering terms), Jan Lewandoski (bridge
and steeple builders' terms), Chris Madigan, Jack A. Sobon and Peter
Wechsler contributed additional entries or emendations. Many of
the joinery terms in this glossary are illustrated in Historic
American Timber Joinery, A Graphic Guide (Sobon), recently
published by the Guild and available at www.tfguild.org or 413-623-9926. For historic English carpentry Alcock, Harris and
Hewett all offer excellent drawings. For illustrations of first-period
New England work, Cummings is probably alone except for J. Frederick
Kelly's Early Domestic Architecture of Connecticut.
- - Definitions for the most part are from Timber
Framing, Journal of the Timber Framers Guild, Number
68, June 2003 issue.
John
Stevens adds this:
The
best glossary I have seen for our subject, but not our region is: An Illustrated Glossary of Early Southern Architecture and Landscape,
by (edited) Carl R. Lounsbury. Uniyersity of Virginia Press, 1994.
430 pages I bought this at Colonial VVilliamsburg. See also: A
Glossary of Colonial Architectural Terms--with illustrations
by Norman Morrison Isham (in-Early American Houses and A Glossary-of
Colonial Architectural Terms--originally published in 1928 and
1939 by the Walpole Society- reprinted by De Capo Press, New York
1967). Also useful are Richard Harris's Discovering-- Timber-Framed
Buildings- Shire Publications Ltd., 1978 and Recording Timber-Framed
Buildings: an Illustrated Glossary- published by. the council
for British Archaeology in 1996.
