IMPROVEMENTS IN FIREPROOF FLOORS
Year: 1884

page_text: I HENRY HEWITT BRIDGMAN of 42 Poultry in the city of London Architect
and Surveyor F.R.I.B.A do hereby declare the nature of my said Invention for
IMPROVEMENTS IN FIREPROOF FLOORS to be as follows:-
This invention relates to certain improvements in fireproof floors the object
being to close all space below board or wooden flooring so as to prevent hollows
and air-ways or draught passage under the wood and so reduce the danger by
burning to a minimum.
On the surface of a prepared bed of concrete or other material I embed at certain
equal distances apart splayed wood fillets resting on the iron joists and dove-tailed
into the concrete, the top of the concrete being brought up level with the upper
surfaces of the fillets. I then apply upon the upper surface a layer of mastic such
as asphalte, lime and air mixture or other cohesive material or compound over the
whole surface, by portions at a time or otherwise, upon which the Hoor-boards are
then to be laid and secured in place by screws or french nails to the fillets, the
fillets being also fixed in place in relation to the iron joists by wrought iron staples
so as to cramp the fillet and the top flange of the iron joist. When the floor
boards are of sufficient thickness say 1 inches they should be and are in some cases
prepared with grooves in the lower edges to form a dove-tailed grip to the mastic
or other cohesive material which will in laying down the boards cause the cohesive
material to squeeze up into the spaces. Floors laid with these dove-tailed edges do
not require to be screwed or nailed at so frequent intervals of distance as without
them but at greater intervals apart. The mastic material so applied will serve to
unite the whole of the floor substances in one thickness from floor above to ceiling
below into a solid cohesive and compact mass. The mastic material may be
omitted if compactness and not cohesiveness be the consideration in which case a
layer of felt sand or other material such as blown slag for instance may be
substituted for it, in which case the dove-tailed grooves need not be formed but all
space between will be closed.
This method of constructing floors not only produces a solid fireproof floor with
an ordinary floor board upper surface but the thickness of the floor may be at the
same time materially reduced; a 13 feet span requires only 8 inches of material
through all from floor to ceiling whereas the method at present in use requires a
thickness varying from 11 inches to 18 inches according to the span and moreover

page_text: having only the underneath side of the floor (or ceiling) of a fireproof character on
account of the hollowness of the upper portion of such floors and the large quantity
of combustible material used in forming the same.
It has been found that floors so constructed soon take fire and flame rapidly, the
internal air spaces materially assisting combustion whilst floors constructed
according to this invention cannot flame but at the most can only gradually
smoulder. The gain in safety consequently is very great whilst the cost of the
construction has been ascertained to be less, all things considered, than that
according to the present method of constructing concrete floors.
Dated this 1st day of January 1884.
WALTER A. BARLOW,
6, St. Paul's Churchyard, E.C.

page_text: "
I HENRY HEWITT BRIDGMAN of 42 Poultry in the City of London Architect
and Surveyor F.R.I.B.A do hereby declare the nature of my invention for
"IMPROVEMENTS IN FIRE-PROOF FLOORS and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to certain improvements in fire proof floors the object
being to close all space below the board or wooden flooring so as to prevent hollows
and air-ways or draught passage under the wood and so reduce the danger by
burning to a minimum.
This method of constructing floors not only produces a solid fire-proof floor with
an ordinary floor board upper surface but the thickness of the floor may be at the
same time materially reduced; a thirteen feet span requiring only seven inches of
material through all from floor to ceiling, whereas the method at present in use
requires a thickness varying from eleven to eighteen inches according to the span
and moreover having only the underneath side of the floor (or ceiling) of a fire-
proof character on account of the hollowness of the upper portion of such floors and
the large quantity of combustible material used in forming same,—it having been
found that floors so constructed soon take fire and flame rapidly-the internal air
spaces materially assisting combustion whilst floors constructed according to this
invention cannot flame but at the most can only gradually smoulder. The gain in
safety is consequently very great whilst the cost of construction has been
ascertained to be considerably less than that according to the present method of
constructing concrete floors.
In the following more particular description reference will be had to the
accompanying sheet of drawings wherein Figs. 1 and 2 respectively show
transverse and longitudinal sections of a flooring constructed according to this
invention and Fig. 3 is a transverse section on an enlarged scale of portions of two
floor boards showing the improved mode of joining the same by dovetailed grooves
to the underlaying mastic or other cohesive material hereinafter referred to.
Upon the surface of a prepared bed of concrete or other material A are embedded
at certain equal distances apart splayed wood fillets B resting on the iron joists C
and dovetailed into the concrete A the top of the concrete being brought up level
with the surfaces of the fillets B. A layer D of mastic such as asphalte, lime and
hair mixture, or other cohesive material or compound is then applied over the
whole of the upper surface by portions at a time or otherwise upon which the
floor boards E are then to be laid and secured in place by screws or French nails
to the fillets B, the said fillets B being also fixed in place in relation to the iron
joists C by means of wrought iron staples F or by wire ties so as to cramp the
fillets B to the top flange of the iron joist C. The underlaying mastic compound is
of itself so cohesive as to securely hold down the floor boards without screws or
nails and the fillets B may be also entirely dispensed with.
When the floor boards E are of sufficient thickness say one-and-a-half-inches
they should be and are in some cases prepared with grooves E¹ in their lower
edges as shown in Fig. 3 thereby forming a dovetailed grip to the layer of mastic
or other cohesive material D which will in laying down the boards cause the
cohesive material to squeeze up into the spaces formed by the grooves E¹.
Floors laid with these dovetailed edges E¹ do not require to be screwed or nailed
at so frequent intervals of distance as without them but at greater intervals apart

page_text: and sometimes not at all. The mastic material D so applied will serve to unite
the whole of the floor substances in one thickness from floor above to ceiling below
into a solid coherent and compact mass.
Where compactness and not cohesiveness is the desideratum the mastic material
D may be omitted and a layer of felt sand or other material such as blown slag for
instance may be substituted for it in which case the dove-tailed grooves E¹ need
not be formed but all space between will be thoroughly closed.
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
The improvements in fire-proof floorings or buildings consisting of the layer of
non-conducting material D laid directly on the concrete A and in immediate
contact with the under-side of the floor boards E to prevent flaming of the
boarding and to attain to a mere smouldering of the wood in the event of a fire
occuring.
D
1 at Jantahan 1001