IN- PROVEMENTS IN THE CONSTRUCTION OF ROOFS FOR BUILDINGS."
Year: 1871

page_text: LETTERS PATENT to Joseph Tall, of Lawson Street, Dover Road, in
the Borough of Southwark, Engineer, for the Invention of "IN-
PROVEMENTS IN THE CONSTRUCTION OF ROOFS FOR BUILDINGS."
PROVISIONAL SPECIFICATION left by the said Joseph Tall at the
Office of the Commissioners of Patents, with his Petition, on the
15th April 1871.
I, JOSEPH TALL, of Lawson Street, Dover Road, in the Borough of
Southwark, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF ROOFS FOR BUILDINGS," to be as
follows:-
My Invention has for its object to construct the roofs of buildings in
such a manner that the space comprised within the roof may be utilized
in a more convenient manner than at present. To this end I construct
the principals or rafters of the roof of bars of iron bent to a curve, so
that when fixed in place they will approach an upright position at the
lower part and will meet at the upper, where they will be bolted or
rivetted together. These principals or rafters are to be placed about two
feet apart, and are kept in place by laterally projecting rods, bars, or
struts which are either bolted, rivetted, or otherwise secured between
Laths of wood, or
them so as to form a kind of open iron framework.

page_text: iron hooping, or wire work, or netting are interlocked between the cross
bars and form a close lattice or basket work. Mortar, plaster, or any
analogous composition is placed on this lath work on each side, and is
trowelled smooth on the inside, so as to form the walls and ceilings of a
room. The outside is covered with stucco, plaster, or other composi-
tion which will resist the wet. I prefer Portland cement stucco for
the purpose. The vertical ribs which form the joints of the stucco are
covered with a rolled rib, which will keep out the water. Dormer
windows may be made in the sides of the roof between the ribs, and the
latter may be further secured and strengthened by means of tie rods and
struts at the upper part.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Tall in the Great Seal Patent Office
on the 14th October 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
TALL, of Lawson Street, Dover Road, in the Borough of Southwark,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of April, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Joseph Tall, Her special licence
that I, the said Joseph Tall, my executors, administrators, and assigns,
or such others as I, the said Joseph Tall, my executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF
ROOFS FOR BUILDINGS," upon the condition (amongst others) that I, the
said Joseph Tall, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and scals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Scal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Joseph Tall, do hereby declare
the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawings here-
unto annexed, and to the letters and figures marked thereon (that is to
say):-
My Invention has for its object to construct the roofs of buildings in
such a manner that the space comprised within the roof may be utilized
in a more convenient manner than at present. To this end I construct
thic principals or rafters of the roof of bars of iron, bent to a curve, so
that when fixed in place they will approach an upright position at the
lower part, and will meet at the upper, where they will be bolted,
rivetted, or otherwise connected together. These principals or rafters
arc to be placed about two feet apart, and are kept in place by laterally
projecting rods, bars, or struts, which are either bolted, rivetted, or
otherwise secured between them, so as to form a kind of open iron
framework. A ridge bar may also be used, if desired, in order to still
further strengthen the structure. Laths of wood, or iron hooping, or
wire work, or netting are interlocked between the lateral cross bars, and
form a close lattice or basket work. Mortar, plaster, or any analogous
composition is placed on this lath work on each side, and is trowelled
smooth on the inside, so as to form the walls and ceilings of a room.
The outside is covered with stucco, plaster, or other composition which
will resist the wet. I prefer Portland cement stucco for the purpose,
but asphalte or other suitable material may be used if preferred. The
vertical ribs which form the joints of the stucco are covered with a rolled
rib which will keep out the water. Dormer windows may be made in
the sides of the roof between the ribs, and the latter may be further
secured and strengthened by means of tic rods and struts at the upper
part.
In the accompanying Drawings I have shewn various ways of carrying
out my Invention.
Fig. 1, Sheet I., is a sectional view of the roof of a house constructed
in the improved manner; Fig. 2 is a side clevation of the same.
a, a, are the principal rafters formed of flat bar iron, placed edgeways.
Their lower ends are embedded in the side walls b, b, of the building,
and their upper ends meet at the top, and are rivetted r bolted together.
These iron rafters or ribs are placed about two feet apart, and are kept

page_text: in position by lateral rods or bars c of round rod or bar iron, which are
screwed or rivetted into the vertical ribs a. If preferred, long rods may
be run through several of the ribs instead of short ones, as shewn in the
Drawing. A ridge bar d, Fig. 2, may be used to keep the ribs in place,
and an open iron framework is thus formed, as shown at Fig. 2. Wooden
or iron laths e, e, are then interlaced over and under the lateral bars c, c,
so as to form a close lattice work, as shown at Fig. 2. A portion of
the roof constructed in this manner is shown at Fig. 3, drawn on an
enlarged scale. When the close lattice work e, e, is completed it is
covered over with concrete composed, by preference, of burnt clay or
hoggin and sand, with a proper proportion, say, one in six or eight of
Portland cement. A metal roll or capping, f, is then placed over
the upper edges of the ribs a, a, and is secured by rivetting or in any
other convenient manner. The surface of the concrete g, Fig. 3, may
then be finished with a coating of neat Portland cement or any other
material which will render it waterproof, and will resist summer heat.
The inside h, h (Fig. 3), of the roof may be plastered and finished in
the ordinary manner. In roofs of large span the two sides of the roof
may be tied together by means of tie rods or bars i, i. Fig. 1, and the
roof may be divided into two rooms by means of a vertical partition j, j,
Fig. 1. If desired the tie rods i, i, may be made to support a ceiling for
the room.
Dormer windows may be made in the roof, as shown at
Figures 1 and 2, and gutters may be constructed along the top of walls
at the base of the ribs c, as shewn at k, k, Fig. 1.
Fig. 4 is an enlarged sectional view of part of a roof in which the con-
struction is somewhat different from that shewn in the former Figures;
Fig. 5 is a side view of the same. In this instance the ribs are made of
Tiron, with the flanges at bottom. The lower ends of the ribs are
embedded in the walls of the building, as in the former instance, and
their upper ends are rivetted or bolted to a flanged ridge plate / which
will keep them in position. Instead of the lateral bars c, c, and lattice
work e, e, the bed of concrete y rests upon a layer or course of short
lengths of match boarding m, m, the ends of which rest upon the
flanges of the T-iron ribs a, a. In constructing a roof of this kind
care should be taken to allow plenty of room for the match boards m, m,
to expand when damped by the concrete, and care must also be taken
to prevent the finer parts of the concrete from getting in between the
boards, and thus preventing them from expanding. A ridge roll is
placed over the top edge of the flanged ridge plate, and rib rolls are

page_text: placed over the top edges of the T ribs, and are embedded in the con-
crete, as shewn in the transverse section, Fig. 6. The under side of
the match boarding m may be stained and varnished, and the flanges or
under part of the ribs a, a, may be painted of any desired colour. A
plaster ceiling may then be dispensed with and a neat appearance may
be given to the interior of the roof.
Fig. 7, Sheet II., is a plan view, and Fig. 8 a transverse section
(drawn on an enlarged scale), shewing a modification of the plan shewn
at Figures 4, 5, and 6. The ribs a, a, in this instance are made of
Tiron, and they are held together laterally by lengths of flat bar
iron n, n, the ends of which are inserted through holes punched in the
web of the T bars, and are turned up and down to prevent them from
being displaced. The spaces between the ribs are filled with breadths of
iron network, either straight or reticulated and of sufficiently fine
gauze to hold the concrete. The flat bars n, n, may be roughly rivetted
together, as shewn at n³, n', and to prevent the iron network from
sagging down when the concrete is placed thereon it may be temporarily
supported from behind by means of boards, which may be removed when
the concrete is set. The inner side of the roof may then be plastered
over and finished in the ordinary manner, or the inside plastering on
the strained wire network may be done first, and will form a support for
the concrete behind. In this instance a metal rib over the top edges
of the T iron is dispensed with, and a ridge is made over the edge and
finished in neat Portland cement to make all water-tight.
Having now described my Invention of "Improvements in the Con-
struction of Roofs for Buildings," and having explained the manner of
carrying into effect, I claim as the Invention secured to me by Letters
Patent as aforesaid, constructing the roofs of buildings of bar iron in
combination with concrete, as herein set forth.
In witness whereof, I, the said Joseph Tall, have hereunto set
my hand and seal, the Fourteenth day of October, in the year
of our Lord One thousand night bundred and