Wood Joints and Splicing

Joints and Splicing

• Joinery refers to the art of forming joints, particularly in woodworking
• Woodworking/Millwork encompasses the work of carpenters and joiners, often seen in stairways, furniture, moldings, and ornamental wood forms
• Moldings are shaped strips of material used as decorative architectural elements, especially in cornices
• A cornice is an ornamental molding placed around a room's wall just below the ceiling
• Baseboard/skirting is a wooden board along an interior wall's base
• Wainscoting involves wood paneling that covers the lower part of interior walls

Types of Wood Joints

• Wood joints are different methods of connecting two pieces of lumber together
• Wood joints are used to build lots of wooden frames and structures

Plain Joint (Lap Joint)

• Used for quick construction of temporary frames
• Achieved by overlapping two pieces and nailing them together
• Considered a weak joint
• It involves overlapping the ends or edges of two members

Butt or Square Joint (End Joint)

• Made by placing the full thickness of one piece of wood against another
• The butt end should be square, and the sides smooth for perpendicularity
• It is the most basic and weakest joint due to only having end-to-end contact
• Variations include end joint, square place, and finger joint

Halved Joint

• A lap joint formed by removing half of each member where they join to create a flush surface
• Also known as a half-lap joint
• To creates a level surface where the joint sits
• Types of halved joints include mitered halving, cross-lap joint, end-lap joint, and dovetail halving
• Mitered Halving: An end lap joint with a miter on one face
• Cross-Lap Joint/Through Half Lap: A halved joint made of two intersecting members
• End-Lap Joint/Corner Half-Lap: An angle joint halving each member to equalize width
• Dovetail Halving

Oblique Joint

• Used when two pieces do not meet at right angles
• Involves cutting one piece at an angle to fit the other before nailing them together securely

Scarf Joint

• Used to unite two pieces of timber end-to-end to create a continuous piece
• The mating surface may be beveled, chamfered, or notched before bolting, gluing, or welding
• Use cases extend wood members

Mortise & Tenon Joint

• Used for building wooden frameworks needing strength and rigidity
• Created by fitting the projecting tenon of one piece into the mortise (hole) of the other
• Variations include through tenon, open mortise, haunched tenon, fox tail wedge and keyed joint

Rabbet Joint

• Formed by cutting a shoulder or edge from one piece to receive another
• Use cases include window/door frames, shelves, and drawers

Dado Joint

• Similar in shape and purpose to a rabbet joint, but features a groove cut at right angles across the grain
• Usually used in furniture making

Miter Joint

• Joins two pieces at a corner
• Not for structural applications needing strength
• Two ends are cut at complementary angles (usually 45 degrees) and butted together
• Securing methods involve clamp nails, finishing nails, corrugated fasteners, dowels, or glue
• Common variations are shouldered and tongued miter joints

Dovetail Joint (Bird's Beak)

• Offers strength and durability for cabinet and furniture work
• Made by fitting a dovetail-shaped pin into a similarly shaped groove
• Variations include lap dovetail, common dovetail, beveled shoulder bird’s mouth, and bridle joint

Coped Joint

• Used to fit one piece of molding at right angles to another
• Common variations are toungue and groove, or butterfly wedge
• Used in ship lapped joints or wood sheathing with rabbeted edges

Types of Nail Construction

• Face Nailing: Nails are driven perpendicular to the material's surface
• Blind Nailing: Also known as concealed or secret nailing, the nail heads are hidden from the surface
• Toe Nailing: Known as skew or tusk nailing, nails are driven at an angle to the surfaces

Types of Wood Framing System

• Framing: The process of fitting pieces together to provide structural support and shape
• Framing materials commonly include wood, engineered wood, and structural steel
• Building framing is divided into light framing and heavy framing

Light Framing

• Employs small, closely spaced members assembled by nailing
• Standard in U.S. suburban housing
• Balloon Framing: A light form where studs and posts run continuously from the sill to the roof plate
• It is not very rigid and liable to sway in heavy winds
• Ribbon/Ribband: A horizontal member housed in balloon framing studs and supports joists
• Braced Frame/Full Frame: A structural system resisting wind and earthquake forces includes girts and braces

Girt

• A horizontal structural member in timber-framed houses
• Typically supports ceiling joist ends and provides the main horizontal support
• Drop Girts support floor joists
• Raised or Flushed Girts run parallel to joists
• Diagonal Braces run from sill to corner post and from corner posts to the roof plate

Combination Frame

• This is a modification of the old braced frame with smaller timbers and uses less mortising

Platform Framing

• Also known as western or stick framing, builds each floor separately to create a platform for the next floor

Top Plate

• The top horizontal member to which rafters are fastened
• Sole Plate: A horizontal timber base for studs

Heavy Framing

• Heavy Framing is common in the Phillipines, and is when floor joists are carried by the the roof
• Studs sit on floor sills across girders/girts on each floor
• Timber Framing: This is the traditional style of building with heavy timbers using fitted and joined joints and secured by pegs
• Pole Framing: A simple technique using large posts buried to give vertical support with girts being the horizontal supports

Partition Wall Framing System

• Partition walls are dividing walls that bear loads
• Stud: Vertical supports in the wall partition
• Partition Cap/Head Plate: The upper horizontal part where the joists rest
• Sole Plate: A horizontal timber base where the stud sits -Cripple: A structural member, like a stud above a door

Constructing Wall Framing

• Wall framing can be done on a platform or on the wall; accuracy ensures sound construction

Wood Post

• Wood posts can be solid, built up, or spaced

Modulus of Elasticity (MOE)

• A measure of a material's resistance to elastic deformation when stress is applied -Measures a woods stiffness

Types of Wood Posts/Columns

• Solid Sawn Column: It’s a single piece of wood, with many different cross sections
• Built-Up Columns: Could be mechanically fastened, or glue laminated
• Spaced Columns: Consists of multiple lumber parts separated by joints
• Box Column: built-up column having hollow, square or rectangular section.

Wood Post on Concrete Pedestal

-Pedestal: A compressed element that holds loads from supported elements

Functions of Concrete Pedestal

• A: Avoid contact between soil and metal elements or wood
• B: To offer support for elements at some elevation
• C: To allow thinner foundation footings

Beam

• Beam: rigid structure member designed to carry and transfer transverse loads across space to supporting elements
• Span: the extent of space between the two supports of a structure
• Clear Span: The inner distance between the supports of a span
• Effective Span: The center distance between supports

Timber Connectors

• Metal additions used to add strength to bolted joints
• Split Rings: Used for heavy load-bearing construction
• Shear Plates: a special plate that increases load carrying capacity
• Toothed Plates & Tooth Rings: Used on two frames
• Clawed Plates: Has two sides in timber connections

Wood Floor Framing System

Consists of joists, and supportive members for carrying flooring

• Floor Joist: A range of parallel beams in concrete,timber and steel holding up floor
• Girder: A larger steel or concrete beam that holds concentrated loads
• Bridging: A system of braces to distribute load
• Cross Bridging: Holds adjacent floor joist
• Block Bridging: Vertical supports that hold the floor joist
• Bridging Floor: A floor held by common joists
• Sleeper Joist: Any joist resting on the timbers supporting floors
• Sleepers: are timbers on a concrete slab where flooring rests
• Ledger Strip a strip which carries joist
• Rim Joist:A joist that sits on the sill of the top perimeter
• Rail Piece: short rafter supported by a wall

Wood Ceiling Framing System

• Ceiling joist, the binding joist or binder, the plate joist and the ceiling strap make it up
• Ceiling Joist: One of a series of several beams to which the ceiling is hung
• Binding Joist/Binder: a beam to support joists of a floor and sits at 90 to it
• Plate Joist: a horizontal board which connects and terminates the ceiling joists
• Ceiling Strap: a strip of wood, nailed to the underside of floor joists
• Ribbands: the ribband is laid flat and fastened to the top of each joist with nails.
• Strongback: prevents twisting or bowing of the ceiling joists
• Attic Scuttle: a ceiling opening for the attic area

Ceiling Metal Framing Parts

- Wall ingle: determines the the ceiling definition
-Double Furring Chanel; supports ceilings
- Carrying Chanel: main support where other supports attach
- Ceiling Hangers: supports the overhead of ceiling framing