Agriculture Reference
In-Depth Information
Pratt reveals how skilled labour is used to rub and gauge (size) ashlared units on
upper and lower beds, the stretcher face, and either header, at 90º to them; only
the rear face abutting the common back-up brickwork is not touched. He com-
ments on the quality of rubbers used and the highly-skilled labour to prepare
and set gauged work made the work around 50 per cent more expensive than
standard front brickwork.
In writing on practical considerations of gauged brickwork in his notebook
for February 1666 Pratt records (Gunther, 1928, 232):
That in all rubbed work where the bricks are to be exactly ground and gauged and
so to be made thinner than those on the inside of the walls, that care be taken that
they may be wrought up together with the inside and so have good bond with it,
and that the white joint to be no more than a quarter of an inch only, and that the
inside of the walls be very well filled whether with mortar at the first, or with hot
lime afterwards.
To this end the rubbing bricks at the first should be made somewhat thicker than
the unrubbed….
Ashlared gauged work was not only reserved for Platt bands and aprons, but (for
those who could afford it) whole fronts in the post-Restoration period. Frequently
set with a larger bed joint of about 5mm (
1
⁄
4
inch) thick, as Pratt described
above, and 2-3mm (
1
⁄
8
th inch) wide for perpends. At this thickness more sand
was required in the mortar and the joint could not be applied to the dampened
rubbing bricks by dip-laying them onto the surface of the prepared mortar in
the dipping box, normal to gauged work with joints typically below 2mm wide,
therefore a 'butter joint' technique was usually employed. This involves holding
the rubber, bed face up, over the mortar and lifting up sufficient on the laying
trowel to deftly apply it along each side, being careful not to smear the face, so
that as the brick is laid to line it has a full bed. Ashlared gauged work with these
wider joints was generally jointed with a 'struck' and sometimes 'ruled' profile, as
can be seen on Wren's ashlared gauged work at Hampton Court Palace (Fig. 70).
Pratt reveals his concern for the problems arising from rubbing bricks being the
same size as standard bricks. Once rubbed, gauged and set on a finer joint, the
outer half-brick façade would immediately fall out of continuous vertical gauge
with the backing brickwork, leading to the question of how best to reconcile and
tie the two leaves together.
There can be little doubt that this contributed to the popularity of the later
common practice of Georgian 'facadism'; though by then it involved first-quality
face brickwork and not gauged work on the outer leaf. Flemish bond was pop-
ular for ashlared gauged work, as well as standard face brickwork, due to the
reduction in headers that could be snapped in two thus, for economy, gaining
two expensive header face bricks instead of one. Tying-in the half-brick façade
with full headers was only practised on an occasional basis. This practice used
