Improvements in Fire-proof or Fire and Sound-proof Floors and Ceilings.
Year: 1899

page_text: Date of Application, 25th Oct., 1899
Complete Specification Left, 19th July, 1900-Accepted, 25th Aug., 1900
PROVISIONAL SPECIFICATION.
Improvements in Fire-proof or Fire and Sound-proof Floors and
Ceilings.
I, PHILIP HOBBS, of 6, Geneva Road, Kingston-on-Thames, in the County
of Surrey, Managing Director of W. B. Wilkinson & Co., Limited, of 13, St.
Mary's Place, Newcastle-on-Tyne, Concrete Specialists, do hereby declare the
nature of my invention to be as follows:-
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This invention which relates to fire-proof or fire-proof and sound-proof floors
and ceilings has for its object to cheapen and lighten the construction of such
floors and ceilings, and increase their fire-resisting and sound-intercepting pro-
perties as compared with the floors and ceilings hitherto constructed for those
purposes.
In a floor and ceiling constructed according to my invention metal joists,
preferably steel, at suitable distances apart are built at their ends into the walls
in the usual manner and on each side of each such joist I fit a skew-back
grooved or shaped at one side to more or less correspond with the contour of
the joist. At the lower part of the skew-backs I provide outwardly-projecting
flanges or rabbets which serve for supporting slabs or plates of fire-resisting
material such as plaster of Paris, such slabs or plates having corresponding
flanges or rabbets to rest on the first-named flanges or rabbets when the said
slabs or plates are dropped, or inserted, from above, into position between the
joists, the slabs being of such size as to fit nicely between and upon the flanges
or rabbets of the skew-backs, and of such thickness as to present at their under-
side, a ceiling-surface level with that of the underside of the skew-backs. The
skew-backs are preferably formed of plaster of Paris and of such size and shape
at the lower part as to leave, between their two inwardly-presented edges, a
dovetail groove, which serves for receiving a portion of the afterwards-applied
ceiling plaster which, when hard, is thereby keyed to the joists. The upper
parts of the skew-backs present ledges for supporting sheets of metal preferably
corrugated grooved, bulged, or expanded, or other sheets having uneven or
rough surfaces such as wire-netting, and over these metal sheets and the joists,
concrete is laid to the required depth so as to present a smooth and even floor
surface the concrete being keyed both to the said sheets and (by engaging with
the flanges of the joists) to the joists also.
If, by the action of fire or by any other cause, the ceiling slabs or plates
should fall or be removed, the strength of the floor would not be lessened and
the floor would still remain both fire-proof and water-proof, and in cases where a
floor is required to be only fire-proof, without also being sound-proof, and where
a level ceiling is not necessary I entirely dispense with the ceiling slabs or plates
the joists being still adequately protected against fire by the skew-backs in
which they are encased.
By constructing a floor and ceiling with the slabs or plates as before described
Dan uninterrupted air-space is provided between the latter and the metal sheets

page_text: and concrete above, without the necessity for using iron bars or hangers such as
have hitherto been employed for supporting suspended ceilings, and moreover
the arrangement is such as to enable the said floor and ceiling to be constructed
without the use of any temporary centreing, thus materially reducing the cost
of construction as compared with ordinary fire-proof floors.
The skew-backs and the ceiling slabs or plates may be cast or moulded in any
desired length and afterwards sawn as required to effect the necessary fitting.
The joints between the ceiling slabs or plates and the skew-backs may be
suitably pointed with cement or the like.
Dated this 25th day of October 1899
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in Fire-proof or Fire and Sound-proof Floors and
Ceilings.
I, PHILIP HOBBS, of 6, Geneva Road, Kingston-on-Thames, in the County
of Surrey, Managing Director of W. B. Wilkinson & Co., Ld., of 13, St.
Mary's Place, Newcastle-on-Tyne, Concrete Specialists, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
This invention which relates to fire proof or fire proof and sound-proof floors
and ceilings has for its object to cheapen and lighten the construction of such
floors and ceilings and increase their fire-resisting and sound-intercepting pro-
perties as compared with the floors and ceilings hitherto constructed for those
purposes.
I will describe my invention by reference to the accompanying drawings in
which Figures 1 and 2 are vertical sections, taken at right angles to each other,
of a portion of one of my improved floors and ceilings. Figure 3 shews in section
a modified construction of the floor and ceiling.
In a Hoor and ceiling constructed according to my invention metal joists A,
preferably steel, at suitable distances apart are built at their ends (as shewn for
example at the left hand end of Figure 1) into the walls B in the usual manner
and on each side of each such joist I fit skew-backs C grooved or shaped at one
side as shewn in Figure 2 to more or less correspond with the contour of the
joist. At the lower part of the skew-backs CI provide outwardly-projecting
Hanges or rabbets c which serve for supporting slabs or plates D of fire resisting
material such as terra cotta, cement, concrete or plaster of Paris, such slabs or
plates having corresponding flanges or rabbets d to rest on the flanges or
rabbets when the said slabs or plates are dropped, or inserted from above, into
position between the joists A, the slabs D being of such size as to fit nicely
between and upon the flanges or rabbets c and of such thickness as to present
at their underside a ceiling-surface level with that of the under side of the skew-
backs. The skew-backs C may be formed of terra cotta, cement, concrete or
plaster of Paris and of such size and shape at the lower part as to leave, between
their two inwardly presented edges, a preferably-dovetail groove el which serves
for receiving a portion e of the afterwards-applied ceiling plaster E which,
when hard, is thereby keyed to the joists A. The upper parts of the skew-
backs C present ledges c² for supporting sheets F of metal preferably corrugated
as shewn in Figure 1, or grooved, bulged or expanded, or other sheets having
uneven or rough surfaces such as wire-netting, and over these metal sheets and

page_text: the joists A, concrete G is laid to the required depth so as to present a smooth
and even floor surface, the concrete being keyed both to the said sheets F and
(by engaging with the upper flanges of the joists) to the joists A. also.
In the modified form shewn in Figure 3 instead of the skew-backs being con-
structed and fitted as previously described I form them of concrete moulded
around the joists constituting solid cast beams for the same and having the
flanges or rabbets c and ledges ².
If by the action of fire, or by any other cause, the ceiling slabs or plates D
should fall or be removed, the strength of the floor would not be lessened and
the floor would still remain both fireproof and waterproof, and in cases where a
floor is required to be only fireproof without also being sound-proof and where
a level ceiling is not necessary, I entirely dispense with the ceiling slabs or
plates D, the joists A being still adequately protected against fire by the skew-
backs C in which they are encased.
By constructing a floor and ceiling with the slabs or plates D as before described
an uninterrupted air-space H is provided between the latter and the metal
sheets F and concrete G above, without the necessity for using iron bars or
hangers such as have hitherto been employed for supporting suspended ceilings
and moreover the arrangement is such as to enable the said floor and ceiling
to be constructed without the use of any temporary centreing, thus materially
reducing the cost of construction as compared with ordinary fire-proof floors.
The skew-backs C and the ceiling slabs or plates D may be cast or moulded
in any desired length and afterwards sawn as required to effect the necessary
fitting
The joints between the ceiling slabs or plates D and the skew-backs C may
be suitably pointed with cement or the like as indicated at i in Figure 2.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
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1. In a fire-proof floor the combination with a metal joist of skew backs so
shaped as to fit against the sides thereof, and cover part of the sides and bottom
flange of the joists and present ledges below the level of the upper flange or
surface of the joist substantially as herein before described with reference to the
accompanying drawings.
2. In a fire and sound-proof floor the combination with a metal joist and skew
backs such as C of flanges or rabbets such as c on the skew-backs, and ceiling
slabs or plates such as D having flanges or rabbets to rest on the flanges or
rabbets substantially as hereinbefore described and illustrated in the accom-
panying drawings.
3. A fire and sound proof floor constructed and arranged substantially as
herein before described and illustrated in the accompanying drawings.
Dated this 19th day of July 1900.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.