Manual of Purpose-Made Woodworking Joinery

FL&B and L&B doors 85

the ledge- thickness) must be diagonally positioned

like gallows’ brackets to support the unhinged side

of the door. The braces are often right- angle pointed

and fitted into the corners, but this has the potential

to push the joints apart, so on good- class work they

are birdsmouthed into the top rail and ledge- edges, as

illustrated at (b) below. The angle- of- lean on braces

above and below the middle ledge should not be less

than 45° and if this cannot be achieved, they should

be lined up and effectively formed as one steep angle.

The ex 125 × 25mm tongued, grooved and vee- jointed

(TG&V ) matchboarding should theoretically cover

Construction details of FL&B doors

Figures 5.10(a)(b)(c)(d)(e)(f )(g): The ex 112 × 50mm
stiles and top rail are joined with haunched mortise-
and- tenon joints and the inner face- edges are cham-
fered, with mason’s mitres where they meet in the top
corners. The ex 175 × 30mm middle- and bottom-
rails, reduced in thickness to allow for the boarded
face – and called ledges instead of rails – are mortised
and bare- face tenoned into the stiles. The bottom
ledge is usually raised up by 40 to 50mm above the
base of the door. The ex 112 × 30mm braces (equal to

25

38

(a)

(b)

(c)

Figure 5.10 (a) Front elevation of a double- ledged framed, ledged and braced door; (b) the birdsmouthed housing-
detail at the top of a diagonal brace; and (c) the inferior method of a right- angle pointed brace positioned in the corner.
Note: in practice, the most successful way of achieving a good birdsmouth fit to the top rail and ledges is to lay the
un- jointed braces in their exact position on the framed- up door, mark the inner door- edges where the braces cross and,
immediately above these points, mark the braces’ edges. Use these marks to form the obtuse- pointed ends of the braces,
then lay them back (in their numbered positions) and mark the birdsmouth shapes with a sharp pencil. When forming the
birdsmouth shapes by saw cuts and chisel- paring, leave the pencil lines showing to achieve a snug fit.

Figure 5.10 (d) Part horizontal section through a FL&B door, showing the final two TG&V boards to be sprung in against
the ledges – and the broken lines indicating the position of the bare- faced tenon. Note that the left- hand and right- hand
edge- boards (and the top edges of all the boards) are usually given a thicker tongue (about one- third of the boards’ thick-
ness), on the inner edges only, as shown above and below at (g).