IMPROVEMENTS IN THE CONSTRUCTION OF FIRE AND SOUND PROOF CEILINGS AND FLOORS
Year: 1882

page_text: LETTERS PATENT to Richard William Hitchins of Stoke Newington in
the County of Middlesex for an Invention of IMPROVEMENTS IN THE
CONSTRUCTION OF FIRE AND SOUND PROOF CEILINGS AND FLOORS
PROVISIONAL SPECIFICATION left by the said Richard William Hitchins
at the Office of the Commissioners of Patents on the 4th December 1882.
RICHARD WILLIAM HITCHINS of Stoke Newington in the County of Middlesex
"IMPROVEMENTS IN THE CONSTRUCTION OF FIRE AND SOUND PROOF CEILINGS
AND FLOORS
"
My Invention relates to improvements in constructing ceilings and in preventing
the transmission of heat and sound through ceilings and floors.
"
In constructing my improved ceiling, I stretch wire netting beneath the joists
and fasten it thereto by hooks or staples in place of the ordinary lathing and fix
temporarily a "centre or flat frame of wood beneath the netting. A composition
to form the body or foundation of the ceiling then poured in between the joists
from above and passing through the interstices of the netting envelops the wire, its
under surface being moulded tolerably even by the "centre or supporting frame
beneath the netting. This body or foundation is afterwards "set" in the ordinary
way to finish the ceiling.
The composition consists of plaster or cement with which is mixed a certain
proportion of coke, breeze, and fibre together with a small portion of alum or
equivalent material.
I also manufacture pugging slabs of the same composition and support them
immediately beneath the flooring boards on the joists or on the fillets between the
joists so as to effectually prevent the transmission of sound and likewise to prevent
the downward spread of fire.
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard William Hitchins in the Great Seal Patent Office on the
4th June 1883.
RICHARD WILLIAM HITCHINS of Stoke Newington in the County of Middlesex
"IMPROVEMENTS IN THE CONSTRUCTION OF FIRE AND SOUND PROOF CEILINGS
AND FLOORS."
My Invention relates to improvements in the mode of constructing ceilings and
in pugging floors to prevent the spread of fire and the transmission of sound.
I construct my improved ceiling without the ordinary lathing, and in its place
I use wire netting which I stretch beneath the wooden joists and fasten thereto,
and I mould the plaster composition upon the wire netting by casting it upon a
moulding table or "centre" fixed beneath the netting by pouring the composition
onto the netting from above in contradistinction to the ordinary method of
rendering or "pricking up" when lathing is used. The ceiling is thus constructed
of plaster composition with wire netting embedded in it to strengthen the plaster
and afford a strong and durable means of fastening the ceiling to the joists and
enabling it to withstand the shock and jars caused by moving heavy packages on
the floor above as in warehouses. I pug the floors by manufacturing pugging
slabs and fixing the ready made slabs upon fillets fixed to the joists at such a
height that the pugging slabs shall be as nearly as possible flush with the top
edges of the joists and therefore immediately beneath the flooring boards.
a is
The drawing partly shows a section of my improved ceiling and pugging and
partly shows the wire netting fixed to the underside of the joists, and the centre
or moulding table applied beneath it ready for casting the ceiling thereon.
the galvanised iron wire netting of any ordinary description and having an open
mesh (say about 1 inch more or less.) This netting is stretched beneath the
joists b to which it is securely affixed by staples c. d is the "centre" or moulding
table having a smooth surface preferably covered with sheet metal when a
finishing coat is not intended to be applied to the ceiling, but it may be of wood
and rough when a finishing coat is to be applied. The "centre or moulding table
may be supported by a strut e from the floor below as shown or suspended from
the joists above. The table has fillets f along two of its outer edges which bear
against the joists and hold the table at the proper distance for the desired
thickness of the ceiling and prevent the plaster over-flowing the edges of the
table.
Having fixed the netting and placed the "centre" in position as shown at the
right hand side of the drawing, I pour in the plaster composition between the
joists from above (and therefore before the flooring boards above are laid.) The
composition passing through the interstices of the netting envelops the wire
netting and its under surface is moulded more or less smooth by the "centre" or
moulding table. When the composition has become sufficiently set, the moulding
table or "centre" is removed to another place and the operation is repeated for à
fresh portion of the ceiling; g shows the ceiling as moulded. If required a
finishing or setting coat may be afterwards applied in the ordinary way to the
whole ceiling when the body or foundation is thus completed.
The plaster composition consists of plaster of Paris or cement with which is
mixed a proportion of pulverised coke with or without a small quantity of vegetable
fibres or hair. The presence of the coke causes the generation of carbonic acid gas
when a fire occurs which gas is evolved in the space between the ceiling and
flooring above and thus prevents the spread of fire.

page_text: h are the pugging slabs cast beforehand of the same material with or without
wire netting embedded therein; they are made of a width corresponding to the
width between the joists and of convenient lengths (about or 6 feet.) They are
fixed on fillets i nailed to the joists at such height that the slabs are nearly flush
with the tops of the joists, the joints between the slabs and joists, and between the
slabs being thoroughly stopped with plaster to make an airtight closure. By this
arrangement of the pugging slabs on a level with the joists, a fire is prevented from
spreading downwards from the floor above, the joists (except in respect of their
upper surfaces which necessarily become charred) being thoroughly protected from
the fire by the pugging slabs.
Having described the nature of my Invention and the manner of performing the
Bane, I declare that what I claim as my Invention to be protected by the berein-
before in part recited Letters Patent is.
1 A ceiling composed of Plaster of Paris or cement, coke, and a small quantity
of vegetable fibre or hair in combination with open meshed wire netting embedded
therein, substantially as shown and described.
2nd The mode of constructing ceilings which consists in casting the plaster or
cement composition around wire netting stretched beneath and affixed to the joists
and moulding the surface of the ceiling upon a table or "centre" temporarily fixed
beneath the netting, substantially as shown and described.
3rd The combination with the joists of a floor, of pugging slabs constructed of
plaster composition with or without wire netting embedded therein, supported at a
level flush or nearly so with the tops of the joists, and of a ceiling applied to the
undersides of the joists and constructed of plaster composition with wire netting
embedded therein for the purpose of protecting the joists from fire, substantially as
specified.
In Witness whereof I the said Richard William Hitchins have hereunto set
my hand and seal this fourth day of June. A.D. 1883.
RICHARD WILLIAM HITCHINS (L.S.)