Framed and glazed building

Freshly felled wood is 45–60% water by weight; air-dried it settles at 12–20%, shrinking across the grain far more than along it. See the wood guide.

• Window frames, sashes, doors and sawn studs must be dry: roughly a year per 25 mm of thickness of air-drying, stacked on stickers under a roof.
• Heavy oak frames were traditionally cut green and pegged with dry pegs: the frame shrinks onto the pegs and tightens. Plan for it, and leave the infill and plaster until the first year's movement is over.
• Never put a dry window into a green frame. The frame shrinks around it and cracks the glass.

Timber in contact with the ground rots; timber kept dry lasts for centuries.

• Build a plinth wall of brick or stone in lime mortar, on footings as for the masonry house.
• Keep the sill at least 150 mm above the ground outside, more in wet climates.
• Lay slate or a course of hard brick under the sill as a damp-proof course, so damp in the plinth cannot wick into the timber.
• Leave air under a suspended floor, with vents through the plinth, so the underside of the floor stays dry.

A frame is cut, fitted and marked flat on the ground, then raised in whole cross-sections called bents.

• Mortise and tenon: the mortise about one-third of the timber's thickness wide, and the tenon filling it without being forced.
• Pegs of dry, split hardwood, 20–25 mm across, driven through holes bored across the joint.
• Draw-bore every joint: bore the hole through the tenon 2–3 mm nearer the shoulder than the holes through the mortise cheeks, so the peg pulls the shoulder tight as it is driven.
• Number every joint on both pieces, so each bent goes together in the same pairing it was fitted in.

A rectangle of timber folds flat under a sideways push; a triangle cannot. A frame without braces racks in the first gale.

• Raise each bent with ropes, pike poles and a full crew, or with a gin pole, and hold it upright with diagonal props until the next bent is joined to it. See knots and lashings.
• Brace every wall in both directions: diagonal braces at about 45° from post to sill or post to plate, at every corner and along every long wall.
• In a light frame, diagonal boarding or diagonal braces let into the studs do the same job.
• Check square by the diagonals: the two diagonals of a rectangle are equal.

Where water power drives a saw and a smithy makes nails in quantity, a house can be framed from small sawn timbers nailed together instead of heavy pegged ones.

• Studs and joists about 50 × 100 mm at 400 mm (16 in) centres, the spacing Griffith's Carpentry gives, because laths and boards come in lengths that divide by it.
• Double the studs beside every opening, with a solid header over it.
• Fire-stop the walls: solid blocking between the studs at every floor, so a fire inside the wall cannot climb it as it would a chimney.
• Plank framing does the same for a barn: sawn planks nailed and bolted into trusses, in place of heavy timbers mortised and pegged (Shawver, 1904).

Window glass came only in small sheets until the 19th century, either crown glass spun from a blown bubble or cylinders blown, cut and flattened. That is why old windows have many small panes held in wooden glazing bars. See Glass.

• Glazing putty is whiting (fine chalk) kneaded with linseed oil until it no longer sticks to the hands. Linseed comes from flax, the same crop as linen cloth.
• Prime the rebates first, so dry wood does not suck the oil out of the putty.
• Bed each pane on a back layer of putty, press it in, hold it with small pins, then face-putty it at a bevel so water runs off.
• Paint the putty once it has skinned, after a few weeks, carrying the paint 2–3 mm onto the glass to seal the edge.
• Size the windows for light: glass of about a tenth of the floor area, half of it opening. Modern building codes ask for 8% glazed and 4% opening.

• Sills slope outward and project past the wall face, with a drip groove along their underside so water drops clear instead of running back to the wall.
• Put a drip cap or flashing over every window and door head, lapped under the cladding above.
• Lap the cladding downward: every board or shingle overlaps the one below it, so water is always led outward.
• Stop the cladding at least 150 mm above the ground, so rain splash does not soak the bottom boards.
• Project the eaves, as for any building in the building guide.

A tighter house is warmer, and it keeps its damp and its smoke.

• Fill the walls with a dry, loose insulation: sheep's wool, sawdust, or chopped straw mixed with lime against rot and vermin. Keep it dry, because wet insulation insulates nothing.
• Single glass loses heat about three times as fast as a solid brick wall of the same area, and ten or more times as fast as a well-insulated wall. Shutter or curtain the windows at night.
• Give every room air: an opening window and a high vent. Condensation running down the glass every morning means the room needs more air, not less.
• Every fire and stove needs its own air supply. A fire in a sealed room makes carbon monoxide.
• Keep the chimney in masonry, with 50 mm of air between it and every timber, as in the masonry house.