Year: 1885

page_text: We JOSEPH SMITHSON THOMPSON and WILLIAM THOMPSON both of Wexford
in the county of Wexford Contractors do hereby declare the nature of the said
invention to be as follows:-
This invention has for its object an improved form of roof by which we can
economise slate or other cover and yet make a waterproof and if necessary, a
ventilating cover.
It consists essentially in making the slate, glass or other material into the form
of a flat, shallow trough with its sides resting on the two adjacent rafters, and
fixing a covering piece over the edges of the two adjacent troughs to cover the
interstice this covering being bolted, spiked or screwed down to the rafter between
the two troughs. The trough can be formed of a flat sheet of glass, slate or tile
with cement edges. One way of forming these is to either nail on or plane out
a fillet on the centre of each rafter and grease, smear or soap the latter with some
material to which cement will not stick, then fill the corner with cement. This
sticks to the slate, glass or tile, but not to the wood and thus leaves the trough
formed of slate, glass or tile and cement free to expand and contract independently
of the rafter. The slates being flat originally, can be made to be flat on each other
or be raised by distance pieces for ventilation. The edges being of cement put on
after, do not interfere with each other in any way. If desirable the fillet can be
dispensed with and two troughs butted up against each other, side by side, a greased
card being inserted between the two contiguous slate edges, while the cement is
being applied to keep the cement edges from uniting. The covering strip can be
metal covered over, preferably shect lead or wood channelled out, or even a flat
lath. This form of covering can be placed on a boarded substructure if desired
instead of bare rafters and can either be attached to the flat plane surface or strips
can be first nailed on above the rafters or otherwise, to represent the fillets already
described.
Among other advantages of this invention are:
1st. Cheapness, as only half the usual number of slates and rafters are required
and no laths are needed.
2nd. Lightness in weight so that smaller scantlings of timber will answer, and
wider spaces obtained than is possible with the ordinary systems,

page_text: 3rd. Ease in repairing, as any defective slates can be replaced easily and perfectly
by removing the metallic capping.
4th. Ventilation can be secured at any part of the roof by inserting distance
slips between the slates.
5th. Economy in lighting, as glass can be substituted for any number of slates
at any part of the roofs (no sashes being required) and fixed in same manner as the
slates.
6th. The slates not having to be pierced with nails and having their cement
edges attached can at any time be taken up on removing the covering strips and
used on another roof.

page_text: We, JOSEPH SMITHSON THOMPSON and WILLIAM THOMPSON, of Wexford, in the
County of Wexford, Contractors, 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:-
i This invention has for its object an improved form of roof by which we can
economise slate or other cover, and yet make a waterproof, and if necessary
a ventilating cover.
It consists essentially in making the slate, glass, or other material into the form.
of a flat, shallow, trough with its sides resting on the two adjacent rafters, which
can be lighter than usual, as they have to carry less weight and fixing a covering
piece over the edges of the two adjacent troughs to cover the interstice, this
covering being bolted, spiked or screwed down to the rafter between the two
troughs. The trough can be formed of a flat sheet of glass, slate or other material
with cement edges. One way of forming these is to either nail on or plane out
a fillet on the centre of each rafter, and grease, smear or soap the latter with
some material to which cement will not stick, (we prefer ordinary oil paint for
this purpose) then fill the corner with cement. This sticks to the slate or glass,,
but not to the wood, and thus leaves the trough formed of slate or glass, and
cement free to expand and contract independently of the rafter. The slates being
flat originally can be made to be flat on each other, or be raised by distance pieces
for ventilation. In practice, we prefer to cut off the two corners of the lower side
of the slate as shown in the drawings before laying.
When the slates are laid in place (with the cut corners exposed), Portland or
other suitable cement is pointed into the rebates in same way as putty is
applied to glass, with this difference that the cement though quite close fitting
to the timber does not adhere to it, but to the slates only, consequently the adjacent
rows of slates have triangular shaped fillets of cement adhering to their edges with
a centre-lath or fillet of wood lying between. This is then covered with a capping
of wood, galvanized iron, zine or lead etcetera, wide enough to over hang the
cement fillets at either side, so that rain can neither drop in directly, nor can
it be blown over the cement into the rebates and cause the rafter to decay.
The upper and exposed portion of each slate is, thus practically fitted with a
turned-up edge (of cement) like a roofing tile; these turned-up edges in adjacent
rows of slates meet on the same rafter with the beforementioned lath or fillet of
timber between them; and the whole joint (in the best kind of slating) is
covered with a capping or half round strip of zinc galvanized iron or sheet lead
fastened with galvanized screws. This capping is thus easily removed at any time
for repairs.
The object of the lath or timber fillet (vailed along the centre of each rafter)
between the rows of slates is to divide the cement so as to leave fillets of same
attached to each slate independently it being a well established fact that slates
will not continue securely cemented together for any length of time owing
to the expansion and contraction caused by atmospheric changes.
The sloping cuts on lower corners of each slate have for an object the conducting
outwards at every lap of any water which may have been blown under the capping,

page_text: whilst at the same time they give the operator the proper direction for cross cutting
the cement fillets at each lap (even if this cross cutting is omitted in the laying of
the roof, this sloping cut on the corners of the slates, will of itself, under expan-
sion and contraction, cause the cement to crack in the right direction.
If desirable the fillet can be dispensed with and two troughs butted up against
each other, side by side, a greased or painted card being inserted between the two
contiguous slate edges, while the cement is being applied to keep the cement edges
from uniting. The covering strip can be metal curved over, preferably galvanized
iron or zinc, but sheet lead or wood channelled out, or even a flat lath will perform
the purpose with more or less success. This form of covering can be placed on a
boarded substructure if desired instead of bare rafters. The substructure may be
either a continuous sheathing all over the upper surface of the rafters, with the
wood fillets fastened on top of the boards or laths or it (the sub-structure) may lie
between the fillets, the latter being made deep enough to admit the boards or laths:
underneath the slates.
For
The drawings show a portion of a roof made in accordance with our invention;
in these A is the rafter, B fillet cut out of or nailed onto A, C slates, D cement
edges. To prevent these from cracking off the slate, it is best to have the edges
of each trough free from those of the contiguous slates above and below.
this purpose therefore when the cement is put on after the slates are in place
a sloping cut E is made and if desirable a greased card as described in the provi-
sional Specification or preferably the painted clips hereafter described is inserted,
so as to prevent the cement of one slate sticking to that of the next. By this
means we get independent expansion. F is the cap that can be of wood, metal or
other suitable material. In practice a stiff cap such as one made of galvanised
iron is superior to a lead one as it helps to keep the slates down. If a lead cap be
used we prefer in place of greased or painted cards to separate the cement edges
of one slate from those of the slate below, to use painted tin or other metallic
clips H nailed to the fillets formed and sloping downward as set forth in Figures 3
and 4. These not merely separate the cements of the contiguous slates, but assist
in holding down the slates themselves. Gholding down screws or spikes.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1st. The manufacture of roofing composed of flat shallow troughs and caps
constructed substantially as described and illustrated.
2nd. The slate, glass or other plates having cement edges and overlapping caps,
substantially as described.
3rd. The method of forming cement and slate (or other plate) shallow troughs
for roofing, each free from each other, yet the cement of one almost abutting
against that of the other, which consists in laying the slates or other plates in the
position they are to occupy, then adding the cement with painted soaped or oiled
division plates, or with oblique cuts between, substantially as and for the purposes
described.
1000