Sovereignty Module: Raise the Frame

Complete Timber Framing, Wood Joinery, and Structural Carpentry Guide

The Philosophy of Timber

Timber framing is the art of building structures from heavy timbers joined by interlocking wood joints, without nails, screws, or metal fasteners. A properly framed timber building can stand for centuries (many medieval timber frames are still in use after 500-800 years). This technique requires only trees, hand tools, and knowledge. No hardware store, no power grid, no supply chain. This campaign provides the complete knowledge to design, cut, and raise timber frame structures from barns to houses to bridges.

Chapter 1: Wood Science for Builders

Structural Properties by Species:

Timber Selection Rules:

1. Straight grain (no spiral, no excessive knots in tension zones)
2. Minimal taper (less than 1 inch per 8 feet)
3. Sound wood (no rot, no insect damage, no ring shake)
4. Proper moisture content (green timber is acceptable for framing if joints are designed for shrinkage; air-dried is ideal)
5. Adequate size (timber should be oversized by 10-20% for safety margin)

Shrinkage:

Green (freshly cut) timber shrinks as it dries. Shrinkage is greatest across the grain (tangential: 6-12%, radial: 3-6%) and negligible along the grain (0.1-0.3%). This means:

• A 12-inch wide beam may shrink to 11-11.5 inches across its width
• But its 20-foot length will not change measurably
• Design joints to accommodate cross-grain shrinkage

Chapter 2: Essential Joints

The Mortise and Tenon (most important joint in timber framing):

A rectangular hole (mortise) in one timber receives a rectangular projection (tenon) from another timber. Secured with a wooden peg (drawbore pin).

Sizing Rules for Mortise and Tenon:

• Tenon thickness: 1/3 of timber width (a 6-inch timber gets a 2-inch tenon)
• Tenon length: 3/4 of receiving timber width minimum
• Mortise should not remove more than 1/3 of receiving timber's cross-section
• Peg diameter: 1 inch for standard joints (3/4 inch minimum, 1.25 inch for heavy loads)
• Drawbore offset: 1/16 to 1/8 inch (peg hole in tenon offset toward shoulder, pulling joint tight)

The Scarf Joint (lengthening timbers):

When a single timber is not long enough, two timbers can be joined end-to-end with a scarf joint.

The Lap Joint:

Two timbers cross or meet with material removed from each so they fit together flush.

Chapter 3: Layout and Marking

The Rule of Thirds:

Timber frame joints follow the "rule of thirds": never remove more than 1/3 of a timber's cross-section at any point. This maintains structural integrity.

Layout Tools:

The Reference Face System:

Every timber has a designated "reference face" (marked with a symbol). All measurements are taken FROM this face. This ensures that even if timbers vary slightly in size, all joints align correctly because they are all measured from the same reference.

Chapter 4: Cutting Joints by Hand

Essential Tools:

Cutting a Mortise (step by step):

1. Mark mortise outline on timber (use marking gauge for parallel sides)
2. Drill out waste with auger (series of overlapping holes within the outline)
3. Chop to layout lines with chisel and mallet (work from both sides to prevent blowout)
4. Pare walls smooth and square with wide chisel
5. Check with tenon (test fit, pare as needed for snug fit)

Cutting a Tenon (step by step):

1. Mark shoulder lines all around timber (crosscut saw depth)
2. Mark cheek lines on end and both edges (rip saw depth)
3. Cut shoulders with crosscut saw (do not cut past the line)
4. Cut cheeks with rip saw (or split off waste and pare smooth)
5. Test fit in mortise (should slide in with firm hand pressure, not hammer blows)

Chapter 5: Common Frame Types

The Bent:

A timber frame building is composed of a series of "bents" (cross-sectional frames) connected by horizontal timbers (plates, girts, purlins). Each bent is assembled flat on the ground, then raised into position.

Post and Beam (simplest):

Vertical posts support horizontal beams. The most basic frame type. Suitable for simple shelters, sheds, and single-story buildings.

Cruck Frame (oldest type):

Two curved timbers (cruck blades) lean together to form both walls and roof in a single arch. No separate wall posts or rafters needed. Extremely strong and simple, but requires naturally curved timbers.

Box Frame (most common historical type):

Posts, beams, and braces form a rigid rectangular frame. Multiple stories possible. Braces (diagonal timbers) provide lateral stability (resistance to racking/leaning).

Hammer Beam (for wide spans without center posts):

Short horizontal brackets (hammer beams) project from the walls, supporting arched braces that meet at the ridge. Allows clear spans of 30-50+ feet without interior posts. The most complex and impressive frame type.

Chapter 6: Raising a Frame

Preparation:

1. All timbers cut, joints fitted, and pegs made BEFORE raising day
2. Assemble each bent flat on the ground (dry-fit, peg together)
3. Prepare raising equipment: pike poles (20-30 foot poles with metal hooks), ropes, gin poles (if available), and many helpers (minimum 10-20 people for a house-sized frame)
4. Prepare the foundation (stone piers, concrete pads, or continuous stone wall)

Raising Sequence:

1. Lay first bent flat, base toward foundation
2. Attach ropes to the top of the bent
3. Helpers push with pike poles while others pull ropes
4. Bent rises from horizontal to vertical (the most dangerous moment)
5. Brace temporarily with diagonal poles staked to the ground
6. Repeat for second bent
7. Connect the two bents with horizontal connecting timbers (plates, girts, purlins)
8. Peg all connections
9. Continue raising and connecting additional bents
10. Install braces (diagonal members that prevent racking)
11. Frame the roof (rafters, ridge, purlins)

Safety During Raising:

• Clear escape routes for all workers
• Never stand under a bent being raised
• Use tag lines (ropes) to control the bent if it goes past vertical
• Temporary braces must be secure before releasing pike poles
• Wind above 15 mph: postpone raising

Chapter 7: Roof Framing

Common Rafter Roof:

Pairs of rafters meet at the ridge, forming triangles. The simplest roof frame. Suitable for spans up to 20-24 feet without purlins.

Roof Pitch:

Rafter Length Calculation:

Rafter length = (half the building width) divided by cosine of roof angle, plus overhang length.

For a 24-foot wide building with 8:12 pitch (34 degrees) and 2-foot overhang:

• Half width = 12 feet
• Rafter run along slope = 12 / cos(34) = 14.5 feet
• Plus 2-foot overhang = 16.5 feet total rafter length

Chapter 8: Bracing and Lateral Stability

A timber frame without braces is a parallelogram waiting to collapse sideways. Braces convert the frame from a mechanism (can move) to a structure (rigid).

Brace Types:

Minimum Bracing:

• Every exterior wall must have at least one brace per bay (space between posts)
• Braces should be in BOTH directions (forming an X pattern when viewed from outside, though not necessarily in the same bay)
• Interior walls/partitions also provide bracing
• A building is only as strong as its weakest bracing direction

Chapter 9: Foundation Options

Critical Rule: Wood must never touch earth (except earthfast posts of rot-resistant species). Sills must be elevated on stone or concrete, with at least 6 inches of clearance above grade.

Chapter 10: Span Tables and Sizing

Beam Sizing (rule of thumb for residential loads):

Post Sizing:

Posts rarely fail in compression (crushing). They fail in buckling (bowing sideways). Bracing prevents buckling.

Reference Card

TIMBER FRAMING ESSENTIALS:

1. Rule of thirds: never remove more than 1/3 of a timber at any joint
2. Drawbore your pegs (offset 1/16-1/8 inch to pull joints tight)
3. Reference face system: measure everything from the same face
4. Braces in both directions on every wall (or it will rack and collapse)
5. Wood must not touch earth (rot prevention)
6. Shrinkage is across the grain, not along it (design joints accordingly)
7. Test-fit every joint before raising day (no surprises at height)
8. Raising requires many hands, clear communication, and escape routes

This campaign provides the complete knowledge to design and build timber frame structures using only hand tools and wood. A community with timber framing skills can build houses, barns, bridges, workshops, and any other structure from locally harvested trees, with joints that last centuries without a single nail or bolt.