80 Making doors and doorframes
sandwiched, square- edged gluelam components (one
vertical and two side arms). The outer, edge- moulded
laminae on each side of the central, tenoned cross
would be 14.5mm thick. To make more sense of this
explanation, see Figure 5.4(f ) above. The other joints
are similar to those indicated for the semi- circular
headed door in Figure 5.4(b).Straight- top tudor- headed doors
Figures 5.4(d) and (e): The top rails of these attractive
Tudor- period doors could be partly (and economi-
cally) built- up on the underside of their joint- ends
for shaping – and, as illustrated, the shoulders should
be part- mitred and splayed to avoid ‘feathered’ edges
and short grain. On exterior doors, the bevelled top
edges of the rails, shown here, would of course act as
weathered edges.Methods of constructing heads of
shaped- doors and/or frames
Figures 5.5(a)(b)(c): Apart from shapes cut uneco-
nomically from diagonally- orientated solid pieces of
timber, illustrated at (a), which can create problems
with short grain, the alternative methods of forming
curved shapes are shown at (b) and (c) below:exception to the norm, G- cramps should be applied
to the cheeks of the open- topped tenons, in addition
to normal cramping with sash cramps. However, the
straight shoulder- abutments, as shown, would only be
possible if the shaped rail had been formed by gluelam
bending. As explained in Chapter 3, this is when thin
laminae (strips of timber) are glued and cramped
together in purpose- built formers to produce curved
shapes. Otherwise, if the curved top rail was formed
by being cut to shape from one piece of solid timber (a
traditional method), the straight shoulder- abutments
would create short grain at the ends of the concaved
shape, so – as shown in Figures 5.4(d) and (e) – the
shoulder abutments should be mitred and splayed.
Semi- circular headed door
Figure 5.4(b): As with all shaped- headed doors, there
are alternative ways to shape the heads and alterna-
tive methods of jointing and joining the heads to the
stiles. Again, the shaping shown here refers to two
quadrant- shaped segments cut from pieces of solid (or
built- up – laminated) timber, jointed at the crown and
to the stiles on the springing line. The springing line is
about 50mm above any intermediate rail. This is done
mainly to promote an easier transition from curve to
straight and partly to create two horns to strengthen
the mortise- and- tenon jointing of the intermediate
rail. Radial- ended tenons are shown on the stiles and
a radial- ended loose- tenon insert is indicated at the
crown. The technique of dowelling described for the
first door should also be used on these three joints.
Traditionally, hammer- headed tenons or separate hard-
wood hammer- headed inserts would have been used
on the three joints in question, but they involve an
enormous amount of work and hand- skills.
Depressed- gothic headed door
Figures 5.4(c) and (f ): Again, there are alternative ways
of shaping and jointing the two arched stiles that form
the head of this type of door. My own idea (to add
strength to the relatively- weak top- heavy arched third
of the door) is to make the top muntin continuous
with the middle muntin, passing as one component
through the intermediate rail and forming a joined-
up, self- supporting cross. Thereby, instead of relying
wholly on side- support from the springing- line joints,
the arched stiles would also be supported by the mun-
tin’s stub tenon into the underside of the crown joint.
To make the cross, yet keep the appearance of the two
muntins being separated by the horizontal interme-
diate rail, it could be built- up with three gluelam
thicknesses: With a door thickness of 45mm, the
tenon- thickness would be 16mm (equal to the panel
thickness) and this would be the thickness of the
Figure 5.4 (f) An exploded isometric view of the built- up
gluelam cross.