IMPROVEMENTS IN THE CONSTRUCTION OF ROOFS
Year: 1876

page_text: LETTERS PATENT to The Reverend Albert Louis Thirion, of Assche-en-Refail
in the Kingdom of Belgium, for the Invention of “ IMPROVEMENTS IN THE
CONSTRUCTION OF ROOFS."
Sealed the 26th June 1877, and dated the 29th December 1876.
PROVISIONAL SPECIFICATION left by the said Albert Louis Thirion at the
Office of the Commissioners of Patents on the 29th December 1876.
The Reverend ALBERT LOUIS THIRION, of Assche-en-Refail, in the Kingdom of
Belgium. IMPROVEMENTS IN THE CONSTRUCTION OF Roofs."
e
According to this Invention boards are slightly overlapped one over the other in
such manner that they form a water-tight roof even without zinc or slates. These
boards rest in the middle upon wedge pieces, at their upper edges upon the rafters,
and at their lower edges upon the boards below. When the boards are not very
wide the wedge pieces may be dispensed with. The part of the board which
overlaps has a groove or rebate into which the upper part of the slate (when such is
employed) enters, or instead of the groove or rebate being formed in the board it
may be formed by placing a small strip of wood of a few millimètres thickness
between the boards. If the boards are carefully overlapped one over the other and
well nailed a perfectly water-tight roof is obtained. Each slate is fastened by
means of one or more nails or screws, or by small hooks fixed in the overlap of the
boards. If care is taken to apply a little mastic to each nail before using it water
will never pass through the boards; if however this should happen it would fall
on the slate below. It is preferred to employ nails which do not quite go through
the boarding. Beneath the adjacent edges of two slates is placed a thin tongue of
zinc or lead, or if preferred the joints of the slates may be covered with a narrow
slate fixed at its lower end by a nail passing into the space between the two slates,
and at its upper end held like the other slates by the overlap of the board above; or
the edges of the slates may be united by what are known as casement learls.
If small hooks are employed for fixing the slates it is not necessary to make.
holes in the latter, the hooks holding on the edges of the boarding.
If preferred a part only of the above described Invention may be employed, that.
is to say, the boarding may be smooth or even, and the slates overlapped a few.
centimetres only, the nails being thus visible; but this method is not so perfect as.
Paving fie/1

page_text: that above described, as the slates do not lay so well on the boards, and any water
which passes through the slates also passes through the boarding unless the latter
is extremely well jointed.
that above described, as the slates do not lay so well on the boards, and any water
which passes through the slates also passes through the boarding unless the latter
is extremely well jointed.
Instead of slates, strips or bands of zinc, lead, or other suitable material may be
used.
By this Invention fewer slates are required; being fixed both above and below
they are more secure, and as they offer no hold to the wind, and are entirely exposed
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Albert Louis Thirion in the Great Seal Patent Office on the 29th June
1877.
The Reverend ALBERT LOUIS THIRION, of Assche-en-Refail, in the Kingdom of
Belgium. "IMPROVEMENTS IN THE CONSTRUCTION OF ROOFS."
According to this Invention boards A, A, see Figures 1 and 2 of the Drawing,
are slightly overlapped one over the other in such manner that they form a water-
tight roof even without zinc or slates. These boards rest in the middle upon wedge
pieces B, B, at their upper edges upon the rafters C, C, and at their lower edges
upon the boards below. When the boards are not very wide the wedge pieces may
be dispensed with. The part of the board which overlaps has a groove or rebate,
as seen in Figure 1, into which the upper part of the slate 1 (when such is
employed) enters; or instead of the groove or rebate being formed in the board it
may be formed by placing a small strip of wood of a few millimetres thickness
between the boards. If the boards are carefully overlapped one over the other and
well nailed a perfectly water-tight roof is obtained. Each slate is fastened by
means of one or more nails or screws (as shown in Figure 2), or by small hooks
fixed in the overlap of the boards. If care is taken to apply a little mastic to each
nail before using it water will never pass through the boards; if however this should
happen it would fall on the slate below. It is preferred to employ nails which do
not quite go through the boarding. Beneath the adjacent edges of two slates is
placed a thin tongue of zinc or lead R, see Figure 2, or if preferred the joints of the
slates may be covered with a narrow slate fixed at its lower end by a nail or screw
passing into the space between the two slates, and at its upper end held like the
other slates by the overlap of the board above; or the edges of the slates may be
united by what are known as casement leads.
If small hooks are employed for fixing the slates it is not necessary to make holes
in the latter, the hooks holding on the edges of the boarding.
If preferred a part only of the above described Invention may be employed, that
is to say, the boarding may be smooth or even and the slates overlapped a few
centimètres only, the nails being thus visible; but this method is not so perfect as
that above described, as the slates do not lay so well on the boards, and any water
which passes through the slates also passes through the boarding unless the latter is
extremely well jointed.
Instead of slates, strips or bands of zinc, lead, or other suitable material may be
used.
By this Invention fewer slates are required; being fixed both above and below
they are more secure, and as they offer no hold to the wind, and are entirely exposed
to the air they last longer than slates fixed in the usual manner.
As herein-before described the tongue of zinc or lead which is placed beneath the
slates at each joint may be replaced by a slate, whereby a double row of slates is
obtained in all parts of the roof, nevertheless fewer slates are employed in this way
than in the system now in use, in which as is well known all slate roofs present
three thicknesses of slates. These tongues of lead or zinc may be made the width
of a slate and to touch each other; the whole of the slates may then be suppressed,

page_text: and instead of cutting the strip of lead or zinc it may be left entire upon the board,
and if preferred several boards may be joined together so as to be wide enough to
receive the whole sheet of lead or zinc, by which means there are fewer steps. The
lead or zinc should be put upon the boards in the following manner, the said
boards being secured to the rafters as the lead or zinc is fixed to them :—
Referring to Figure 6 the upper side of the board is first covered with a strip or
sheet of lead or zinc rather wider than the board. One edge of the strip or sheet is
turned under the board and nailed thereto; this board is then placed upon the rafters
of the roof, and the strip or sheet of lead or zinc being raised the board is nailed or
otherwise secured to the rafters, the strip or sheet of lead or zinc is then lowered on
to the board without nailing it thereto unless it be at the upper part which is to be
covered by the next board N, which latter fixes the lead or zinc still more securely.
By these means the surface of the lead or zinc remains intact, and neither nails nor
screws are seen.
The boards may also be fixed to the rafters from the interior of the roof, that is
to say, from the loft or attic by means of screws; in this case each board should be
prepared beforehand with its strip of lead or zinc fixed thereto.
As before described the boards may be arranged to overlap each other, and they
then form of theinselves a water-tight roof, the slates also overlap or project over
the board a few centimêtres, the lower slates entering below the board above, and
at the same time under the slates above; but as already explained the boards may
be arranged in the ordinary way, care being taken however that the slates overlap
a little.
The boards being overlapped form a series of steps of about 2 centimètres height,
that is to say, the thickness of the board. It is however desirable to reduce this
thickness to 3 or 4 millimêtres in order to preserve the boards from the action of
rain and sun; this may be offected by making in the lower edge of the board one or
two small grooves or rebates. If two are used the slate enters the first one, as
shown at A in Figure 4, and the second rebate marked B in the same Figure is
placed on the upper edge of the lower board. If one groove or rebate only is used,
as that marked D in Figure 3, it is placed on the upper edge of the lower board,
and the lower slate simply comes against the edge C of the upper board without
entering below it.
In the case of a single rebate D the upper end of the lower slate may be raised
against the under side of the lower end of the upper slate M, M ; for that purpose
the board should be slightly rounded or a small lath R, Figure 3a, placed on the
upper part thereof; or there may be on the upper part of the board a shallow rebate
or bevil long enough to allow any water which may reach it by accident to descend
easily over the upper surface of the board instead of falling behind it or into the
joint of the two boards, see S Figure 3b, where the board is shown simply bevilled.
A similar bevil may be made on the lower board where the upper board has two
rebates, see S Fig 3c, and I consider these are preferable arrangements.
If preferred instead of overlapping, the boards may be arranged in the form of
steps of a few centimêtres height, see Figure 5, the slates being simply laid against
the ends of these steps.
As above described the slate is held at the upper end without nails or screws, and
at its lower end by means of either; but I prefer to employ screws and to place
under the heads thereof small washers of lead or other suitable substance, by which
means water cannot get through the boards. The screws may be fixed in any con-
venient place near the bottom of the board.
The slate may be fixed below without piercing it by means of a small square (or
angle piece) or hook E (see Figure 5), secured by a screw or otherwise to the
board.
Having now described the nature of the said Invention and the manner in which
the same is to or may be performed, I would have it understood that what I claim.
as my Invention is,―
First. The use in roofs of overlapping boards arranged as a series of steps, as

page_text: herein-before described and illustrated in the Drawing, and for the purpose set
forth.
Second. The employment of grooves or rebates in the aforesaid overlapping boards
for the purpose of receiving and holding in position the upper edges of the slates,
and for adapting the upper board to the next below, as herein-before described and
illustrated in the Drawing.
Third. The method of fixing the slates by nailing or screwing them to the boards
near their lower ends, and supporting them at their upper ends either in grooves or
rebates or against the edge of the board above without nails or screws, as herein-
before described and illustrated in the Drawing.
Fourth. The employment of tongues of metal or slate beneath the adjacent edges
of the slates, as herein-before described and illustrated in the Drawing.
Fifth. The employment, in combination with overlapping boards, of strips, bands,
or sheets of lead or zinc, as herein-before described and illustrated in the Drawing.
In witness whereof, I, the said Albert Louis Thirion, have hereunto set my
hand and seal, this Twenty-eighth day of June, in the year of our Lord One
thousand eight hundred and seventy-soven.