IMPROVEMENTS IN THE CON- STRUCTION OF FIRE-PROOF FLOORS."
Year: 1881

page_text: LETTERS PATENT to Ernest Homan, of Turnham Green, in the County of
Middlesex, Engineer, for an Invention of "IMPROVEMENTS IN THE CON-
STRUCTION OF FIRE-PROOF FLOORS."
PROVISIONAL SPECIFICATION left by the said Ernest Homan at the Office
of the Commissioners of Patents on the 19th November 1881..
ERNEST HOMAN, of Turnham Green, in the County of Middlesex, Engineer.
"IMPROVEMENTS IN THE CONSTRUCTION OF FIRE-PROOF FLOORS."
The object of this Invention is the construction of fire-proof flooring formed by
metal bars and concrete.
In carrying my said Invention into practice I first erect or set up stages
of the requisite height, upon which I lay a temporary platform, or centres or
stretchers of wood level with the underside of the intended floor. This platform
I cover all over to the depth of about one inch with good concrete, made of
Portland cement (by preference), gypsum, lime, or plaster, mixed with the requisito
quantity of Thames ballast, gravel, broken stone or brick, burnt clay, or other
approved material, in the proportion of one part of the cement by measure to from
three to eight parts of the hard material.
Upon this concrete I lay a series of flat metal bars of a scantling varying
according to the span and area of the floor, and also the strain which such floor is
intended to bear, say, one inch wide by a quarter-inch thick for an ordinary floor
of a span of about eight feet; these metal bars have a safe bearing on the walls or
on brackets, or on main girders, and are placed at from about six inches to two
feet apart, according to the span of the floor or section of the metal bars used, or
intended strain on such floor. I then lay transversely upon the said bars and at
varying distances apart, as herein before stated, similar flat metal bars which are
bolted or rivetted to the under bars at each point of their crossing.
When this metal framework is completed I cover the whole with a layer of
concrete, as hereinbefore described, well worked and evenly spread, and of a
D..... Al

page_text: thickness of from four to eight inches or more according to the strength of floor
required.
When the concreto is thoroughly set, which will generally be in a week or ten
days if Portland cement be used, I remove the said temporary platform and its
supports, when the ceiling and the upper surface of the floor can be finished as
desired.
By my improved method of crossing and uniting the metal bars flat instead of
edgewise, the sectional area of the concrete is diminished proportionately less.
The metal is also applied in a more efficient manner by thus placing it at its
greatest distance from the neutral axis of the floor.
By securing the metal bars together at each crossing, they are prevented from
sliding, and from being dragged away from the concrete, and also from separating
from each other. The tensional strains being thus provided for in both directions
the strength is thereby doubled.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Ernest Homan in the Great Seal Patent Office on the 19th May
1882.
ERNEST HOMAN, of Turnham Green, in the County of Middlesex, Engineer.
"IMPROVEMENTS IN THE CONSTRUCTION OF FIRE-PROOF FLOORS."
The object of this Invention is the construction of fire-proof flooring formed by
metal bars and concrete.
In order that my said Invention may be more fully understood and be more
readily performed, I will explain the same with the aid of the accompanying
Drawing which forms part of this Specification, reference being made thereto
by the numerals and letters marked thereon. The same index lettor refer to similar
parts in each Figure of the said Drawing.
Fig. 1 is a plan of my improved method of constructing fire-proof floors.
Fig. 2 is a longitudinal section of the same on the line A, B, Fig. 1.
Fig. 3 is a transverse section of the same on the line C, D, Fig. 1.
Fig. 4 is an enlarged plan of my improved method of connecting the longitudinal
and transverse bars together, where they cross each other.
Fig. 5 is an elevation of the same.
In carrying my said Invention into practice, I first erect or set up stages of the
requisite height, upon which I lay a temporary platform, or centres, or stretchers of
wood level with the underside of the intended floor. This platform I cover all
over with good concrete about an inch thick, made of Portland cement (by
preference), gypsum, lime, or plaster, mixed with the requisite quantity of ballast,
gravel, broken stone, or other approved hard material, say, in the proportion of one
part by measure of the cement to from three to eight parts of the hard material.
Upon this concrete I lay a series of flat metal bars a of a scantling varying
according to the span and area of the floor, and also the strain which such floor is
intended to bear, say one inch wide by a quarter-of-an-inch thick for an ordinary
floor of a span of about eight feet. These bars a have a safe bearing on the walls
of the building, or on brackets attached thereto or on main girders c, and are
placed at from about six inches to two feet apart according to the span of the floor,
or the section of the metal bars used, or the intended strain on such floor.
I then lay transversely upon the bars a and at varying distances apart, as
herein before stated, similar flat metal bars 6 which are rivetted to the under bars a,
or, by preference, united thereto by screw-bolts and nuts e at each point of their
crossing, the screwed ends e' of such bolts projecting into the concrete to obtain a
better hold therewith, see Figs. 4 and 5 of the Drawing.
When this metal frame-work is completed I cover the whole area thereof with a
layer of concrete d, made as herein before described, well worked and evenly spread,
and of a thickness of from four inches to eight inches or more, according to the
strength of floor required.
a
When the concrete d is thoroughly set, which will generally be in a week or ten
days if Portland cement be used, I remove the temporary platform and its
supports, when the ceiling and the upper portion of the floor can be finished as
desired.
By my improved method of crossing and uniting together the bars a and b flat
instead of edgewise, the sectional area of the concrete is thereby diminished
proportionately less. The metal is also applied in a more efficient manner by thus
placing it at its greatest distance from the neutral axis of the floor.
By securing the bars a and b together with the screw-bolt and nut e at each
crossing thereof, and by the bolt e being securely gripped at its screwed end c¹ by

page_text: the concrete d, the said bars are thereby prevented from sliding, and from being
dragged away from the said concrete d, and also from separating from each other.
The tensional strains of the said floor being thus provided for in both directions,
the strength of such floor is thereby doubled or nearly so.
Having thus fully described and ascertained the nature of my said Invention,
and the method of performing the same, I hereby declare that I do not claim as
now the use of metal bars nor of concrete per se in the construction of floors,
knowing that both those matorials have previously been used, but what I claim as
my Invention and desire to secure by the herein before-mentioned in part recited
Letters Patent is,―
Firstly. The method of securing the metal bars together flatwise at each of
their points of crossing, substantially as described and shown in the Drawing.
Secondly. The method of constructing fire-proof floors with wrought-metal bars
united with screw-bolts and nuts and with concrete, substantially as described
and shown in the Drawing.
In witness whereof, I, the said Ernest Homan, have hereunto set my hand
and seal, this Eighteenth day of May, in the year of our Lord One thousand
eight hundred and eighty-two.