Improvements in the Construction of Fireproof Floors.
Year: 1894

page_text: Date of Application, 1st Mar., 1894
Complete Specification Left, 30th Nov., 1894-Accepted, 5th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Fireproof Floors.
I, ROBERT ASTLEY, of 34 Ely Place, Holborn, in the City of London, Architect,
do hereby declare the nature of this invention to be as follows:-
The object of this invention is to provide an efficient protection for the underside
of the joists and girders used to support "solid concrete" floors it having been
found in practice that the thin layer of concrete on the underside of the joists is
very apt to crack and fall away especially in the case of a fire or in rooms which
are heated to a high temperature owing to the expansion of the metal caused by
the heat.
Now according to this invention I provide a number of 1 shaped tiles or lintels
of fireclay or other incombustible material the underside of the flange being
provided with dovetailed or other suitably shaped grooves to receive the ceiling
plaster.
The web of the lintel is wider at the top than where it joins the flange to secure
the same in the concrete. These tiles or lintels are placed on each side of the
joists and girders and the space between filled up with concrete the flanges of
the tiles forming an efficient protection for the underside of the flanges of the
joists aud girders.
It will be understood that as the tiles are disposed longitudinally and not crosswise
as usual the concrete must be supported until set.
I prefer to make the flange wider on one side of the web than on the other
thereby enabling one size of lintel to protect joists having flanges of different
widths.
Dated this 1st day of March 1894
T. E. HALFORD,
11, Furnival Street, Holborn, London, E.C., Agent for the Applicant.
Improvements in the Construction of Fireproof Floors.
I ROBERT ASTLEY of 34 Ely Place Holborn in the City of London Architect,
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 :-
The object of this invention is to provide an efficient protection from fire for
the underside of the joists and girders used to support "solid concrete" floors it
having been found in practice that owing to the expansion of the metal the thin
layer of concrete on the underside of the joists is very apt to crack and fall away
especially in the case of a fire and also in rooms which are heated to a high
temperature.
Now according to this invention I provide a number of 1 shaped tiles or lintels
of fireclay or other incombustible material the underside of the flanges being
provided with dovetailed or other suitably shaped grooves to receive the ceiling
plaster.

page_text: The web of the lintel is wider at the upper edge than where it joins the flange
to secure the same in the concrete. These tiles or lintels are placed on each side
of the bottom flange of the joists and girders and the space between the said joists
and girders filled up with concrete the flanges of the tiles forming an efficient
protection for the underside of the flanges of the joists and girders.
It will be understood that as the tiles are disposed longitudinally and not crosswise
as usual the concrete must be supported until "set."
I prefer to make the flange wider on one side of the web than on the other
thereby enabling one size of lintel to protect joists having flanges of different
widths.
And in order that my said invention may be fully understood I will proceed
to explain the same with reference to the accompanying sheet of drawings in
which
Fig. 1. represents partly in section a portion of a fire proof concrete floor
constructed according to this invention.
Fig. 2 is side view of tile or lintel.
Fig. 3 is end view of same.
The same letters denote the same parts in all the figs.
a a are the metal joists.
bbbb the lintels or tiles of fire-clay terra-cotta or other suitable incombustible
material.
c the concrete d the ceiling plaster.
As will be seen from Figs. 2 and 3 the lintel consists of a web e wider at the
top than at the bottom where it joins the flanges. The flanges ffare of unequal
width so that by placing the two narrow or wide flanges together or one wide and
one narrow flange together one size of the tile or lintel will protect any joists now
in use for flooring purposes.
h. h are grooves in the flanges ff into which the concrete and plaster enter thus
affording an additional support to the lintels.
ggare dovetailed grooves in the underside of the flanges to receive and form a
key for the ceiling plaster.
The hereinbefore described method of constructing concrete floors affords perfect
protection to the joists and girders while allowing for their expansion, avoids
the discoloration of ceilings from exposed metal, dispenses with the use of
wire netting and prevents the concrete from breaking away from the underside
of joists.
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:
1. In the construction of fireproof floors the lintels bb of fireclay or other
incombustible material having an upright web wider at the top than at the
bottom and flanges ff of unequal width the said flanges being grooved or recessed
at h h and having grooves g g in the underside thereof all substantially as and for
the purposes stated.
2. In the construction of fireproof floors the combination of metal joists such
as a with lintels or tiles such as 6 having upright webs wider at the top than at
the bottom and flanges of unequal width and concrete c between the joists
substantially as specified.
3. Constructing fireproof floors and lintels therefor, substantially as hereinbefore
specified and shewn by the accompanying drawings.
Dated this 30th day of November 1894.
T. E. HALFORD,
11, Furnival Street, London, E.C., Agent for Applicant.