IMPROVEMENTS IN FIRE PROOF FLOORS
Year: 1885

page_text: I JAMES DOULTON of the Pottery Works Lambeth in the County of Surrey
Potter do hereby declare the nature of my invention for "IMPROVEMENTS IN FIRE
PROOF FLOORS" to be as follows:-
This Invention has for its object improvements in fireproof floors.
Fire proof floors of large span are usually laid upon box girders supporting other
girders or joists of H iron which cross the box girders transversely. In order to
render such floors fire proof I enclose the box girders in casings of fire proof
material.
I cover the lower flange of the girder with tiles made of fire clay. The width of
these tiles corresponds with that of the underside of the girder and the flanges of
the tiles project up on either side and turn inwards overlapping the lower flange
of the box girder. These tiles are made in convenient lengths. The two sides
of the box girder are protected by flat fire tiles; these rest upon the lower flange of
the girder and against the flanges of the tiles which cover the underside of the
girder-The width of these flat tiles is such that they just fit in beneath the upper
flange of the girder and here they are kept in place by the flooring blocks which are
laid between the H iron joists The ends of these blocks are notched to receive
the upper flange of the girder and this admits of their abutting upon the tiles
which protect the side of the box girder. Or the tiles protecting the sides of the
girder may be, made taper and of sufficient thickness at the top to render the
notching of the flooring blocks unnecessary. These tiles in this case are made with
longitudinal hollows which serve as air passages.
There are also air channels between the tiles and the girder.
The surfaces of the tiles by which the girders are encased may be ornamented.
The girder. case it will be observed is not dependent on cement to hold it
together; it is self supporting.
The flooring blocks are also preferably moulded in fire clay and they have
passages through them to lighten them to form air spaces and facilitate burning-
These blocks are adapted to form flat arches between the H iron joists which are
usually several feet apart. These flooring blocks are of several patterns. The
block adjacent to the Hiron joist is made on one side to a form adapted to fit to
the joist and to overlap it on the underside. These blocks extend beneath the
joist so far as the centre of the joist where it meets the similar flooring block
applied on the other side of the joist—Thus the underside of the joist is completely

page_text: encased. The other side of the block which abuts upon the joist is inclined and it
forms the springing of the flat arch extending from joist. This inclined side of the
block is in two slopes with a shoulder between to break the joint-this strengthens
the arch and under some circumstances facilitates the laying of the floor. The
intermediate blocks between those which abut upon the joists are rhomboidal in
section with sloping sides formed with shoulders or stops as already described-
The central block is of a wedge form with the apex downwards with sides
corresponding to those of the other blocks. This block is the last to be inserted
and it keys the other blocks in place.
Dovetail grooves are also formed in the abutting faces of the blocks; these serve
to give a key to the mortar or material in which the blocks are bedded. The
underside of the blocks also have dovetail grooves formed in them to give a key to
the plaster which forms the coiling of the room.
Floors of small span are laid without the box girders.
I JAMES DOULTON of the Pottery Works Lambeth in the County of Surrey
Potter 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:-
This invention has for its object improvements in fire-proof floors.
Fire-proof floors of large span are usually laid upon box girders supporting other
girders or joists of H iron which cross the box girders transversely. In order to
render such floors fire-proof I enclose the box girders in casings of fire-proof
material.
I cover the lower flange of the girder with tiles made of fire clay. The width
of these tiles corresponds with that of the under side of the girder and the flanges
of the tiles project up on either side and turn inwards overlapping the lower flange
of the box girder. These tiles are made in convenient lengths. The two sides of
the box girder are protected by flat fire tiles; these rest upon the lower flange of the
girder and against the flanges of the tiles which cover the underside of the girder
The width of these flat tiles is such that they just fit in beneath the upper flange
of the girder and here they are kept in place by the flooring blocks which are laid.
between the H iron joists. The ends of these blocks are notched to receive the
upper flange of the girder and this admits of their abutting upon the tiles which

page_text: protect the side of the box girder. Or the tiles protecting the sides of the girder
may be made taper and of sufficient thickness at the top to render the notching of
the flooring blocks unnecessary.
These tiles in this case are made with longitudinal hollows which serve as nir
passages.
There are also air channels between the tiles and the girder.
The surfaces of the tiles by which the girders are encased may be ornamented.
The girder case it will be observed is not dependent on cement to hold it together;
it is self supporting.
The flooring blocks are also preferably moulded in fire clay and they have
passages through them to lighten them to form air spaces and facilitate burning.
These blocks are adapted to form flat arches between the H iron joists which are
usually several feet apart. These flooring blocks are of several patterns. The block
adjacent to the H iron joist is made on one side to a form adapted to fit to the
joist and to overlap it on the underside. These blocks extend beneath the joist as
far as the centre of the joist where it meets the similar flooring block applied on the
other side of the joist. Thus the underside of the joist is completely encased. The
other side of the block which abuts upon the joist is inclined and it forms the
springing of the flat arch extending from joist to joist. This inclined side of
the block is in two slopes with a shoulder between to break the joint this
strengthens the arch and under some circumstances facilitates the laying of the
floor. The intermediate blocks between those which abut upon the joists are
rhomboidal in section with sloping sides formed with shoulders or stops as already
described. The central block is of a wedge form with the apex downwards. with
sides corresponding to those of the other blocks. This block is the last to be
inserted and it keys the other blocks in place.
Dovetail grooves are also formed in the abutting faces of the blocks; these serve
to give a key to the mortar or material in which the blocks are bedded.
The under side of the blocks also have dovetail grooves formed in them to give a
koy to the plaster which forms the ceiling of the room.
Floors of small span are laid without the box girders.
In order that my said invention may be most fully understood and readily carried
Figure 1 is a vertical section of a fire proof floor constructed in accordance with
my invention; the section is taken transversely through one of the under
supporting girders.
Figure 2 is a vertical section of the floor taken transversely through two of the
H iron joists.
a is the box girder and b b are the joists which it supports. c is the moulded
fire tile which protects the bottom of the box girder overlapping its lower flange.
dd are the tiles protecting the sides of the box girder; they are kept in place at
the bottom by the tiles c and at the top by the flooring blocks which project down
between the joists.
The tiles d d as represented in the drawing are taper and their upper edges are
flush with the edge of the upper flange of the box girder. Or if the tiles are
not made to come flush with the upper flange of the girder, the flooring blocks
abutting on the girder may be notched to admit the flange.
ee are the flooring blocks which abut upon the joists, they are moulded with
passages through them and of a form to fit to the joist and encase its lower flange.
The other or outer sides of the blocks e are inclined in two slopes with a shoulder
between and with dovetail grooves for the mortar or material in which the blocks
are bedded.
ff are the intermediate blocks: these are of rhomboidal form and have their
sides or faces similar to the faces last described.

page_text: g is the central or key block; it is wedge form and with faces corresponding to
those of the blocks on which it abuts. The floor blocks are grooved on the under-
side to give a key to the plastering.
I sometimes make the arch with a certain amount of rise in the centre and in
this case it is less necessary to form the sides of the blocks in two slopes with a
shoulder between.
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
(1.) In the construction of fire proof floors casing the sides and lower flanges of
the supporting box girders with tiles, the lower tiles having flanges overlapping
the girder flanges and aiding in keeping the side tiles in place substantially as
described.
(2.) Constructing fire proof floors with H iron joists and with arches formed
with hollow blocks of refractory pottery with inclined sides in two slopes with a
shoulder between substantially as described.
(3.)-Constructing fire proof floors with H iron joists and with arches formed
with hollow blocks of refractory pottery, the blocks abutting on the joists over-
lapping and encasing their lower flanges substantially as described.
(4.) Constructing fire proof floors with H iron joists and with arches having
springing blocks abutting upon the joists and overlapping and casing them on the
underside substantially as described.
(5.)-Constructing fire proof floors with supporting box girders and with H iron
joists and flooring blocks supported on the joists; such box girders being protected
at their sides by tiles kept in place beneath their upper flanges by the flooring
blocks projecting beneath the joists substantially as described.
(6.) Moulded blocks and tiles for the construction of fire proof floors substan-
tially as described and represented by the annexed drawings.