Manual of Purpose-Made Woodworking Joinery

Panelled doors 81

partly because the jointing of frames seems to have

changed from mortises- and- tenons (requiring horns)

to comb joints (not requiring horns), and partly due to

improved frame- fixing screws.

Nowadays, to improve a dwelling’s energy rating

in compliance with changes in Part L of The Building

Regulations, more attention must be given to draught-

seals and weather- seals and there is a wide (and

confusing) range of these available from ironmongery

The opposite edges are usually rounded or splay-
moulded. Traditionally, they were bead- moulded and
the head and sill were given 50 to 75mm horns on
each side, which were splay- cut on site and built in to
the brickwork. The former (bead- moulding) might
still be used occasionally, but the latter are not. This
is partly because the horns create more work for the
bricklayer, partly because – if the frames are inset – the
horns clash with the vertical DPC in a cavity wall,

(a) (b) (c)

Figure 5.5 (a) This semi- circular construction is formed with two solid- timber quarter- turns, with their grain tangential to
the curves (as indicated) and can be jointed at the crown with a loose tenon (or a double tenon) insert and at 50mm
below the springing line with single or double jamb- or stile- tenons; (b) shows a semi- circular door- or frame- head made-
up of gluelam laminae with a thickness equal to the semi- circle’s inner radius divided by 150; the shape is glued and
set up in a purpose- made male and female former; and (c) is of a similar construction to (a), but the short grain and the
timber wastage is less severe; structurally, the side- thickness of the shape is made up of two layers of four pieces on one
side and five on the other, with the radial joints staggered on each side. On one side the joints are positioned at 45°,
90° and 135° and on the other side (shown dotted) they are at 22.5°, 67.5°, 112.5° and 157.5°.

(a) (b)

Figure 5.6 (a) A cross section through a 95 × 57mm par doorjamb and/or frame- head with a 12 × 46mm inset
rebate, a splay- moulded face and a traditional mortar- groove in the back – which could be omitted nowadays. The
12mm edge of the doorstop has a saw kerf, or router groove, into which a Raven tubular- type silicon- rubber compression
seal is push- fitted. The vertical broken lines indicate the possible division for five- fingered comb jointing. (b) This cross
section is through a140 × 45mm hardwood sill, with the comb- jointed doorframe jamb in the background (giving a part-
elevational view of the tubular compression seal) and a partly open, weather- boarded door with a rebated bottom edge.
Similar to the doorframe’s rebates, the door’s underside rebate is grooved and fitted with a more cylindrical- type Raven
tubular silicon- rubber compression seal. This closes against the compressible fin of the upstanding PVC water- bar fitted
into the grooved sill. Note that these corner- fitted, tubular- type compression seals seem to me to be better able to cope
with the conflicting geometry of the closing hinge- side edge approaching the seals from a different direction to the door’s
top- face and lock- edge face.

Exterior frame details

Figures 5.6(a)(b): Whether of softwood or hard-
wood, an exterior frame should be of a substan-
tial width and thickness, usually not- less- than 95 ×
57mm par (finish), from which rebates of at least
12 × 46mm should be removed to house the door.