Manual of Purpose-Made Woodworking Joinery

Boxframe windows and double- hung sashes 55

(non- opening) and only the central sashes open, the

mullions are solid – not boxed. This was done to lessen

the size of the mullion and gain more light through

the window. However, the cording and weight- fitting

of such centrally- positioned opening sashes is more

complex, as the cords have to run across the heads

of the fixed side lights to reach the outer boxes, as

illustrated below.

Multiple boxframe windows

Figures 4.2(a)(b)(c)(d)(e): Double- hung sashes pre-
dominate in single pairs, but can be in two or three
pairs, with boxed mullions dividing them. Such
windows are known technically as one- light (one
pair of sashes), two- light, or three- light, according to
the number of pairs in each. In three- light windows,
when the usually- narrower side lights are fixed

AA

Figure 4.2 (a) Exterior elevation of a two- light box-
frame window with two pairs of sliding sashes hung on
traditional sash cords and weights. Section A- A below
shows the detail of the boxed mullion. Note the joggles
shown above on the top sashes (which are not only used
to avoid dovetailed joints between the sash stiles and
meeting rails, but are also reckoned to give better support
to the mortise- and- tenoned meeting rails carrying the
glass); if you imagine this drawing as being upside down,
that would be the interior appearance of any joggles on
the bottom sashes.

15

20

11

1

4

18

9

18

10 10

18

(^2115)
1
20
9
11
18
5
Figure 4.2 (b) Horizontal section A- A through the double-
boxed mullion in Figure 4.2(a), showing (1) pulley stiles;
(4) double inner- lining (166 × 20mm par); (5) double
outer- lining (198 × 20mm par); (9) parting beads; (10)
wagtails; (11) sash stiles; (15) staff beads; (18) high and
low sash weights; (20) joggles (of bottom sashes); (21)
box divider (94 × 6mm plywood) – traditionally of sawn
softwood.
C
BB
C
Figure 4.2 (c) Exterior elevation of a three- light boxframe
window with boxed outer- jambs (similar to those detailed
in Section views D- D and E- E above), two solid mullions,
two pairs of fixed (non- opening) sashes and one central
pair of sliding sashes hung on traditional sash cords and
weights. Section B- B below gives a detailed view of one
of the mullions and Section C- C shows the concealed
cording- arrangement at the head of the fixed sashes. Note
the dotted lines indicating the cording and weighting of
the central top- sash.
15 15
(^2020)
11 11
21
5
9 9
Figure 4.2 (d) Horizontal section B- B through a solid
mullion in Figure 4.2(c), showing (5) 76 × 20mm par
outer lining; (9) parting beads; (11) sash stiles; (15) staff
beads; (20) joggles (of bottom sashes); (21) solid mullion
(108 × 44mm par).