IMPROVEMENTS IN NONCONDUCTING CEILINGS AND FLOORS, AND PARTITION WALLS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by John William Gray at the Office
of the Commissioners of Patents on the 27th May 1881.
JOHN WILLIAM GRAY, of Birmingham, in the County of Warwick, Civil
Engineer. "IMPROVEMENTS IN NONCONDUCTING CEILINGS AND FLOORS, AND
PARTITION WALLS."
My Invention has for its object improvements in nonconducting ceilings and
floors, and partition walls, and is intended to supersede the present lath ceilings,
which are easily destroyed by fire, and which present but little obstruction to the
transmission of sound, and also to be used between present ceilings and floors to
prevent sound.
According to my Invention I use a special composition or compositions, the
constituent parts of which will be hereafter more fully explained, and which is
almost indestructible by fire, while it effectively deadens sound.
This composition is moulded into cakes or blocks of suitable size and shape to
drop between the joists forming floors, or to fasten on to the under side of the
joists.
The face of these cakes or blocks would then receive a thin layer of plaster,
composition, paper, or other material, and afterwards the whitewash or paint in
the usual way.
If wood joists are used a fillet would be nailed on to each side forming a rabbet.
The cakes or blocks would also be moulded with rabetted edges to fit upon the
said fillets so that the face of the cakes would be a little lower than the under face
of the joists. To cover the underface of the joists supplemental cakes would be
inserted, or a little plastic composition would be used to level the surface. In
other cases the cakes would be placed upon the under face of the joists to which
they would be fastened by flat headed nails, or in any convenient manner. The
edges might be left square and the nails driven between the edges, or they
could be rabbeted so as to fall one over the other, and the nails driven through
both cakes. The space remaining between the cakes and the floor above could
then be filled up with any suitable material, such as composition in a dry state, or
in cakes on fillets between the joists, or sawdust, which would rest directly upon
the ceiling or cakes which are sufficiently strong to carry such a weight.

page_text: Where iron is used I roll a special form of joist, which is also applicable to floors
where my composition is not used, but in conjunction with my composition cakes
the floor is practically indestructible by fire. My special rolled joist has a flange at
its lower part forming a double rabbet to receive the cakes, while the top has a
flange with a dovetailed recess for the purpose of receiving strips of timber to
which the flooring boards are nailed. In some cases, where the joists are used
without my composition cakes, the bottom flange of the joists may also be
dovetailed to receive a strip of timber to which the cakes may be nailed. My
composition cakes or blocks would also work well with present section used for
iron joists, i. c., the double T or girder section as the bottom flange constitutes a
suitable bearing for the blocks. The shoulder of the rabbet of these cakes would
in some cases be made of a dovetail shape so as to hold the supplemental cakes or
plastic composition for filling up the spaces under the joists.
The composition I have found most suitable has for its constituent parts-
One third clay, two thirds water and willow dust, which may be varied by the
use of other fibrous material. These are well mixed together in a suitable pug mill
and moulded into the desired shape. The blocks are then placed in ovens or kilns
and baked perfectly dry and hard, so as not to either break or crack by exposure to
heat. These blocks are both tough and light, and the floors made of them would
be dry from the very commencement.