An Improved Form and Method of Construction of Fire-proof Floors...
Year: 1892

page_text: Date of Application, 14th May, 1892
Complete Specification Left, 7th Dec., 1892-Accepted, 14th Jan., 1893
PROVISIONAL SPECIFICATION.
An Improved Form and Method of Construction of Fire-proof Floors...
ROBERT ASTLEY Architect 34 Ely Place Holborn E.C. do hereby declare
the nature of this invention to be as follows
:-
This floor is proposed to be constructed with iron joists about 2' 0" apart-
between the joists specially made fireclay lintels are placed. The lintels are
formed in the shape of an inverted T. The top of the T to form a flat ceiling and
the upright piece or web to be cut to a curve in such a manner that loose curved
tiles can be placed over them. Concrete would then be laid on top of all, which
concrete would take the form of a continuous arch springing from joist to joist.
Slots would be cut at both ends in the web of the lintel to allow the flat underside-
of lintel to go under the bottom flange of iron joists and so protect same from fire..
The underside of lintels would have grooves to receive ceiling plaster.
Dd this with 1 of M.- 1005
ROBT. ASTLEY.
COMPLETE SPECIFICATION.
An Improved Form and Method of Construction of Fire-proof 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 construct fire-proof floors in such a manner
as to provide efficient protection in case of fire to the joists and girders supporting
them, which joists or girders being made of iron or steel are very apt to give
way by bending when heated to any great extent.
Now according to this invention I provide a number of joists of iron or other
suitable metal about two feet apart and between the joists are placed lintels of
fireclay or other fireproof material of 1 cross section. These lintels are placed
with their flanges horizontal to form a Hat ceiling the upright web being curved
to allow of tiles, preferably curved, sheet metal or other suitable material pre-
ferably incombustible, being placed over them. On the tiles, sheet metal or
other suitable material is placed a layer of concrete flush with or covering the
top of the joists and thus forming an arch springing from joist to joist without.
the aid of temporary centering. Slots are cut in both ends of the lintels to
allow the flange of the same to pass under the bottom flange of joists and
girder and protect the same from fire. The underside of the flange of the
lintels is grooved to receive ceiling plaster, and in order that my said invention
may be fully understood, I will proceed to explain the same with reference to
the accompanying drawings in which.
Figure 1 represents longitudinal section of a fire-proof floor constructed according
to this invention.
Figure 2 is cross section of same.
Figure 3 is side view of lintel.
Figure 4 is end view of the same.
Figure 5 plan of a portion of a fire-proof floor to a smaller scale shewing the
lintels in section, also constructed according to this invention.
The same letters, denote the same parts, in all the figures.

page_text: A is the main girder, B the joists, C the lintels, D sheet iron or other incom-
bustible material placed on the lintels, E concrete resting on the sheet iron, tiles,
or other incombustible material D. F flooring joists, G wood flooring boards.
H grooves in lintels to receive ceiling plaster, I; K apertures in lintels for ventila-
tion, L an aperture in flange of same communicating with the room below if
desired. M M air flues in wall N, O, 0, 0, air bricks, air flues and air bricks may
be omitted, if desired.
The lintels C which are made of fireclay or other fireproof material are provided
with slots Pat each end as shewn at. Figure 2 and 3 to allow the flange of the
same to pass under the joists B and main girder A and protect them from fire.
The slots P are sufficiently deep to allow of the lintels being canted over so as to
enable the flanges to be passed one under the other, and as the said lintels have
only one upright web, they may be turned or slewed to enable them to be placed in
position after the joists are fixed.
When all the lintels except the last one in each bay have been placed on the
joists the flanges of each of the last four or five are placed one under the other, and
the lintels being pushed up close leave room for the last one to be placed in position
on the joists and the other four or five are afterwards separated and placed in their
proper positions.
To provide ventilation between the ceiling and the undersides of the concrete
arches apertures K are formed in the web of the lintels C, air bricks 0, 0, 0, may be
provided in one or more outer walls to admit fresh air. The vitiated air from
between the ceiling and the concrete may be removed by means of the flues M M
in the walls. By forming apertures in the flanges in two or more of the lintels as
at L the room or rooms below may be ventilated by means of the flues M M which
are connected directly to the air chambers in the floor.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is :-
1st. In the construction of fireproof floors, the lintels C of fireclay or other fire-
proof material and of approximately 1 section having an upright curved web with
or without apertures therein and flat bottom flanges forming projecting tongues
substantially as and for the purpose specified.
2nd. In the construction of fireproof floors the combination of the lintels C of
fireclay or other fireproof material as described in Claim 1 resting on metal joists B
with tiles, sheet metal or other suitable material D and concrete arches E all
substantially as described and shewn by the accompanying drawings.
Dated this 6th day of December 1892.
FREDK. WALKER,
11, Furnival Street, Holborn, London, E.C., Agent for the Applicant..