Improvements in the Construction of Fireproof Floors and Ceilings.
Year: 1894

page_text: Date of Application, 8th Dec., 1894
Complete Specification Left, 9th Sept., 1895-Accepted, 19th Oct., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Fireproof Floors and
Ceilings.
I THOMAS POTTER of 7 Outram Road, Croydon, Secretary to a Public
Company do hereby declare the nature of this invention to be as follows:-
--
Fireproof floors are sometimes made by depositing between, or on top of metal
joists, concrete resting on platforms or centres, which are removed when the
concrete is hard. These platforms or centres are generally supported by props, or
posts, resting on the floor or ground beneath. I dispense with these props or
posts, and instead thereof I employ metal hangers somewhat in the form of the
letter Z. The upper member, or limb, of the metal hangers rests upon the wall or
upon the metal joists which support the floor. I place these hangers any distance
apart, and make them of any suitable dimensions and upon the bottom limb I rest,
in a direction parallel with the walls or posts, timber of any required size, between.
which and the bottom member of the hanging iron I place folding wood wedges or
metal keys. Upon these timbers I rest others crosswise and reaching from joist
to joist; and on the crosswise timbers I place corrugated iron or wood boards to
form a platform or centreing. Sometimes I dispense with these cross timbers and
use only corrugated iron or boards whose ends rest upon the timbers which are
parallel with the walls or joists. Upon the top of the centreing or platform and
corresponding with the top members of the hanging irons, or metal hangers,
When the
I place blocks of wood somewhat larger than the said members.
corrugated iron, or wood platform, is removed by slacking the folding wedges,
these blocks drop out and leave a core or cavity which permits of the hanging
irons or metal hangers being liberated sideways. The top member of the metal
hanger is made taper so as to move out freely with slight pressure sideways, by
means of a lever or wedge.
Another part of my invention consists in the insertion of hangers in the soft
concrete, to support metal lathing bars to attach lathing to, to form a ceiling.
These hangers have mortices at their lower ends through which the lathing bars
slide, and are of a similar character in this respect to the one shown by d.
Figure 5 and K Figure 3 of a Patent granted me in 1893 No. 4259 dated
February 27/1893 but the upper parts are straight and have holes or mortices
thereon, through which pieces of metal are passed to obtain a grip on the concrete
and to regulate the distance of the hangers below the temporary centreing through.
which they pass.
The bottom ends of the hangers may be formed to hold the
lathing bars by means of a book shape fang with wedge and key instead of a
mortice.
Another improvement consists in forming burnt clay flange shields to protect
the bottom flanges of the metal joists from heat during a conflagration. Instead
of making these shields in two parts as shown by C Figure 5 of a Patent granted
me in 1894 Number 22978 and dated November 30, 1893 I make them in one piece,.
and slide them on the joists from their ends before the joists are fixed; by this
means no joint is shown beneath the joists.
I also mould these casings of an ornamental character, or groove or roughen
them to enable them to be covered with plaster, if required.
Another part of my invention consists of hangers similar to those shown by D
Figure 4 of a Patent granted me in 1894 No. 22978 and dated 30 November 1893

page_text: but with fangs or nuts and screws to uphold fibrous plaster or other slabs used for
ceilings. These hangers rest upon the bottom flanges of the joists or upon the
flange casing shields. In the former case they are provided with a wedge shape
clip to hold them rigid to the joist.
Another improvement for the purpose of constructing fire proof floors which
have to be performed in a limited time, or for immediate use is to cast concrete
slabs an inch in thickness and upwards, which are placed between tee metal joists,
or on top of double flanged joists. I sometimes intervene the clay flange shields,
previously described, between the concrete slabs and the bottom flanges of the
joists to protect the latter in case of fire.
Dated this Eighth day of December 1894.
Improvements in the Construction of Fireproof Floors and
Ceilings.
I, THOMAS POTTER, of 7 Outram Road, Croydon, Surrey Secretary to a
Public Company 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 :-
Fireproof floors are sometimes made by depositing between or on top of metal
joist, concrete resting on temporary platforms which latter are removed when the
concrete is hard. These platforms or centres are usually supported by wood props
or posts resting on the floor or ground beneath. I dispense with these props or
posts and in lieu thereof I employ metal hangers as shewn by Fig. 1 somewhat in
the form of the letter Z. The upper members of the hangers rest upon the wall
or upon the top flanges of the metal joists which are to support the concrete floor.
I place the hangers any distance apart and make them of any suitable dimensions
and I also vary their shape as may be found necessary without departing from the
principle described.
Upon the bottom limb of the hanger I rest in a direction parallel with the
joists, timber of any requisite dimensions which I call plates and on these plates
I rest other pieces of timber crosswise and reaching from joist to joist called
bearers; between the bearers and the plates I insert folding wedges. I cover the
entire space or area between the joists with a rough wood platform to support the
concrete in a soft state. Sometimes I use corrugated or plain sheet iron instead
of boarding. To enable the hangers to be withdrawn after the floor has got hard
I use wood core blocks somewhat larger in size than the top member of the hangers.
When the platform is removed by slacking the folding wedges the core blocks.
drop away and leave a cavity which permits the hanging iron to he withdrawn.
The top member of the hanger may be made taper so as to move out freely
sideways by means of a lever or wedge.
A is a steel joist. B. hanger. C. plate. D bearer. E folding wedges.
F platform. G core blocks. H concrete.
For the purpose of deadening sound I sometimes employ metal hangers clipping
lathing bars which rest on clay or other fireproof blocks. I insert pads or blocks
of asbestos or other non combustible materials, between the bottom flanges of joists
and the hangers to check the transmission of heat. I then cover the lathing bars
and hangers with metallic lathing of any description, for plastering upon to form a
ceiling.
Figure 2 is a section of this arrangement. A is a steel joist. B burnt clay or
other bearing block. C concrete slab. D metal hanger. E lathing bar. G metal
Jathing. H plaster ceiling. J asbestos blocks.. L air space between floor & ceiling..

page_text: Where it is necessary to panel a ceiling or form a fireproof cornice I let the bars
rést upon the bottom flanges of the joists and between the clay shields. I suspend
metal hangers to the lathing and secured thereto by means of wedges, bolts, nuts,
or pins as circumstances require. The hangers form cradling of any shape required,
to which is fixed metallic lathing for forming a plaster cornice upon. By these means
I'get a large air space round the bottom flange of joist which is a great advantage.
in case of fire, and enables cornices to be constructed without the use of any wood
or other combustible materials and of very light weight.
Figure 3 illustrates my meaning A is a steel joist. B burnt clay shield
C concrete floor. D iron hanger or cradling Elathing bar. F plaster cornice -
and ceiling. G air space.
Another part of my invention is shewn by Figure 4 and refers to the insertion
of hangers in the soft concrete to support metal lathing bars when necessary.
These hangers have mortices therein at their lower ends through which lathing
bars pass and are in this way upheld; they are similar in character to the one.
shown by d. Figure 5 and K Figure 3 of a Patent granted me in 1893 No. 4259
and dated Feb. 27/1893 except that the upper parts are straight and have a similar
mortice to the bottom, and through which a pin or wedge is passed and embedded
in the soft concrete during construction.
A is a steel joist. B hanger. C concrete D lathing bar. The bottom portion
of the hanger may be made with a hook shape fang, and wedge and key in place of
a mortice.
Another improvement consists in forming burnt clay flange shields to protect the
bottom flanges of steel joists. Instead of making the shields in two parts as shown
by C Figure 5 of a Patent granted me in 1894 numbered 22978 and dated
Nov. 30th 1893 I make them in one piece as Figure 5 sliding them on the joists.
from the ends before the said joists are fixed. A is a steel joist and B is a flange
shield.
I also mould these shields of an ornamental character if desired as C Figure 6
or groove and roughen them to enable them to be plastered if desired. I make
them of burnt clay, concrete, terra cotta, plaster of Paris or any other suitable
material.
Another improvement consists in casting concrete slabs in moulds or in situ, and
resting them between or on top of the upper flanges of steel joists. Figure 7
shows a steel joist A, and flange casing and shield combined B, made of any of the
materials previously described and fixed or bedded to the metal joist. C is a
concrete slab. The flange casing and shield also forms a support for the concrete
floor. The shape or form of casing and shield may be altered according to
circumstances or taste.
Where the passage of sound is an objection I fix thin cast slabs preferably of
plaster-but they may be of any other material-beneath the floor slab-leaving
an air space between, as shown by Figure 8.
A is a steel joist. B fibrous plaster or other flange shield or casing, C fibrous.
plaster or other ceiling slab, D concrete floor slab, E air space.
I vary the way in which I perform the various purposes described as circumstances
require, and may be found desirable, without departing from the general methods
shewn by drawings and described in Specification.
I do not claim the use of boarding or platforins to form bearers to uphold
concrete in a soft state, nor the use of steel joists instead of wood, nor of slabs
made of concrete in moulds or in situ but
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1st. Forming temporary platforms without support beneath, which can be easily
and quickly performed, practically as shown by Figure 1

page_text: 2nd. Encasing steel joists whereby in case of fire they are entirely separated
from contact with ceiling, practically as shown by Figure 2.
3rd. The formation of skeleton metal cradling.or encasement for the construction
of plaster cornices and ceilings, practically as shown by Figure 3.
4th. Suspending metal lathing to concrete floors by means of metal hangers,
practically as shown.by Figure .4.
5th. The construction of flange shields made in one piece practically as shown
by Figure 5.
6th. The construction of ornamental flange shields, practically as shewn by
Figure 6.
7th. Flange shields and girder encasing to support concrete floors, practically as
shown by Figure 7.
8th. Flange shields and girder encasing to support fibrous or other plaster
ceilings with air space to prevent sound practically as shown by Figure 8.
Dated this 7th day of September 1895.
רד- A
THOMAS POTTER.