IMPROVEMENTS IN THE MEANS OF PROTECTING THE JOISTS OF BUILDINGS FROM FIRE
Year: 1884

page_text: I CHARLES TOOPE of Stepney in the County of Middlesex, Manufacturer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MEANS OF PROTECTING THE JOISTS OF BUILDINGS FROM FIRE," and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
My Invention relates to means of protecting the joists of buildings from fire,
and it consists in fire proofing the joists of buildings by means of blocks or slabs of
fire proof material of such shape as to adapt them to, engage with fillets or flauges
on the joists and with one another so as to be self supporting, in cementing such
slabs together with a cement composed of pipe-clay and silicate of soda, and, when
desired, covering the blocks or slabs with asbestos sheeting.
In order that the Invention may be more readily understood, I have illustrated
it in the accompanying Drawings forming part of this Specification, and will proceed
to describe it with reference thereto.
Figures 1 and 2 are cross sections of floors and ceilings showing the Invention
applied to wooden and iron joists respectively. In the case of wooden joists I
nail fillets a along each side of the joists at the lower edge to support the blocks
or slabs. These blocks or slabs b forming the fire-proof ceiling composed as above
described are moulded of the forms shown and of such width that three slabs will
bridge over the space between two joists and fit together as shown. The slabs
adjacent to the joists are moulded with a rebated grooved edge to adapt them to
fit on the fillets a of a wooden joist, or the lower flange a¹ of an iron girder
or joist, and extend under the same as far as the centre line and rise up the side of
the same above the fillet or flange, the thickness above and below being sufficient
to support the weight of the slabs and to protect the joist from fire and afford
nail hold for the lath and plaster. The other edge, and the edges of the central
block, are preferably rebated so as to form an indented joint as shown, but the
joint may be oblique like that of an ordinary flat arch if desired.
In order to strengthen the slab or block where it fits on the fillet or flange of
the girder, U shaped pieces of metal are embedded in the material at suitable
distances apart at the time of moulding and the blocks or slabs next to the girders
are made of greater thickness than the centre blocks or slabs.

page_text: The central slab is placed between the lateral ones after the latter have been
placed in position on the joists, and the joints between them, as well as the joint
beneath the joists, are cemented with the fire proof cement composed of pipe-clay
and silicate of soda (mixed in suitable proportions to form a cement) to make, a
tight joint and prevent the passage of heat and smoke.
The slabs which might conveniently be made in lengths of from 1 to 3 feet
would simply butt joint and be cemented with the same fire proof cement.
After the slabs are placed in position the lower side is, if required, lined or
coated with the asbestos sheeting, said sheeting being cemented to the slabs with
the same cement. The ordinary lathing may afterwards bo nailed to the slabs.
The fire proof slabs would be applied in a similar way to rafters and to the
studs of partition walls.
In applying the slabs beneath the wooden flooring to protect the joists from
burning downward, they may be jointed together in the same way and are
supported on planks c resting on the joists as shown in Figure 2, but in the case
of warehouses &c these fire proof blocks or slabs may themselves constitute the
floor or wearing surface without the ordinary wood flooring.
The blocks or slabs may be made of any suitable fire proof material. They
would however by preference be made of the materials specified in another
application for Letters Patent filed by me and bearing even date herewith.
my
Having now particularly described and ascertained the nature of said
Invention and in what manner the same is to be performed, I declare that what
I claim is:
1 The construction of a fire-proofing for joists, of hard coherent blocks or
slabs composed of fire-proof material, adapted to engage with fillets or flanges on
the joists or timbers and with one another, as and for the purpose described, the
blocks or slabs being cemented together as specified.
2nd The combination with a fire proofing formed of slabs as specified in claim 1
of asbestos sheeting secured thereto by a cement composed of silicate of soda and
pipe-clay.