Raise a wooden frame

Cut, notch, lash, and peg posts and beams into a strong skeleton that will carry the roof.

hard⏳ two weekstradition — not yet hand-tested

A frame is the skeleton of the house: upright posts, horizontal beams tying their tops together, and sloped rafters carrying the roof. Get the skeleton right and everything after — walls, roof, door — just hangs on it. Get it wrong and no amount of mud or thatch will save a house that leans a little more each winter.

The whole craft comes down to three ideas: joints that lock wood to wood, triangles that stop wobble, and keeping wood away from wet ground. Everything below serves one of those three.

You need

• 6 to 9 posts — split or round trunks, a hand-span thick (about 15 cm), each a head taller than you plus a knee-depth extra for the ground. Use your most rot-proof wood for these: oak, chestnut, cedar, or black locust if you have them.
• 4 or more beams — for the tops of the walls (these top beams are called plates) and across the width (tie beams). Same thickness as posts.
• Rafters — a pair of poles for each roof slope, arm-thick, meeting at the top.
• Many pegs — hard, dry wood whittled to finger-thick, a hand long, slightly tapered.
• Cordage for lashing — strong rope or bark cord, and the lashings you learned: square lashing holds two crossing poles.
• Axe, sharp knife, maul, wedges — from your wood-splitting kit.
• A water level or line level — a long clear tube of water shows level between two points; or hang a stone on a string (a plumb line) to show true vertical.
• Two helpers for raising days — one person can cut a frame alone; standing it up safely wants three.

Steps

1. Draw the plan on the ground, full size. A rectangle about 3 by 4 paces is a fine first house. Check it is square with the diagonal trick: measure both corner-to-corner diagonals with a cord — when they are equal, the corners are true.
2. Protect the post feet before anything goes in the ground. Wood rots where damp and air meet. Char the bottom knee-length of each post in a fire until the surface is blackened all round — charcoal resists rot — or, better, stand posts on flat stones at ground level instead of burying them.
3. Set the posts.
   • Dig each hole knee-deep, a bit wider than the post.
   • Drop in a flat stone for the post to stand on (so it doesn't sit in wet soil).
   • Stand the post, hold your plumb line against it on two sides, and pack the hole with fist-sized stones and rammed earth in thin layers, checking vertical as you go.
   • Brace each post temporarily with two leaning poles lashed on, until the frame ties it in.
4. Bring all post tops to one level. Use the water level between posts and mark, then cut the tall ones down. A level top now saves endless trouble later.
5. Notch the tops for the beams. The simplest strong joint is a lap joint: cut a flat-bottomed notch halfway into the post top, and a matching notch halfway into the beam, so they nest into each other flush. Cut notches slightly small and pare to fit — you can remove wood but never put it back.
6. Peg and lash every joint.
   • Bore or burn a hole through the overlapped joint (a hot iron rod, or careful drilling with a stone or metal-tipped bit), and drive in a dry, slightly fat peg with the maul. Dry peg in green wood is the secret: the wood shrinks around the peg and grips it forever.
   • Where you cannot peg, square-lash tightly and check the lashings each season.
7. Add the tie beams and, above all, the braces. A rectangle of posts and beams can still fold sideways like a book closing — that folding is called racking. Triangles stop it: lash or peg a short diagonal pole across every corner, from partway down each post up to the beam, at roughly 45 degrees. Do not skip a single corner. Braces are the difference between a frame and a trap.
8. Raise the roof triangles. Lash each pair of rafters together at the top on the ground first, add a horizontal cross-piece partway down (making the pair a rigid A shape), then lift each A onto the plates and peg or lash its feet. Cut a small notch (a bird's-mouth) where each rafter foot sits on the plate so it cannot slide. Aim the slope steep — about 45 degrees, meaning the roof rises as much as it runs — if thatch is coming; steep roofs shed rain fast.
9. Tie the ridge and shake the frame. Run a pole along the rafter peaks (the ridge) and lash every crossing. Then grab a post and heave in every direction. It should feel like one solid thing. Anything that shifts gets another brace or a tighter lashing today, not later.

Watch out

• Raising is the danger day. Beams overhead can fall; lift with your legs, keep everyone on the same side, agree on the words ("up — hold — down") before you lift, and never stand under a beam that is not yet pegged.
• Buried untreated posts rot at the ground line in a few years — the house then stands on rotten ankles. Char the feet, stand them on stones, and slope the earth so water runs away from every post.
• Skipping braces because "it feels solid today." Green lashings loosen and soil settles. The first big wind finds every missing triangle. Brace every corner, both directions.
• Knots and cracks in a post carry the whole house. Put your cleanest, straightest wood in the posts and plates; use knotty pieces for braces and short bits.
• A frame out of square fights you forever — nothing after it fits. Re-check the diagonals after the posts are set and again after the plates go on, while things can still be nudged.
• Green wood shrinks as it dries. Expect joints to loosen in the first months; walk the frame each moon and re-drive pegs and re-tighten lashings.

How it works

Wood is hugely strong along its length — a finger-thick peg can hang a person — but joints are where frames live or die. A lap joint makes two sticks share the same space so load passes through wood, not just through rope. Pegs lock the joint; the triangle braces do the rest, because a triangle is the one shape that cannot change without a side breaking. Post, beam, peg, triangle: that skeleton has held roofs up for five thousand years.