IMPROVEMENTS IN THE CONSTRUCTION OF ROOFS
Year: 1860

page_text: LETTERS PATENT to Thomas Martin, of Withybush, Haverfordwest, in
the County of Pembroke, Clerk, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF ROOFS."
Sealed the 4th October 1860, and dated the 11th April 1860.
PROVISIONAL SPECIFICATION left by the said Thomas Martin at the
Office of the Commissioners of Patents, with his Petition, on the 11th
April 1860.
I, THOMAS MARTIN, of Withybush, Haverfordwest, in the County of
Pembroke, Clerk, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF ROOFS," to be as follows:-
The object of this Invention is to make slate roofs not only impervious to
water, but also non-conductors of caloric.
In carrying out my Invention I first nail down battens in a longitudinal
line upon rafters of the roof. According to the size of the slates to be placed
upon them so will the distances apart of the battens vary. For instance, if
duchesses be applied, the distance from centre to centre of the battens must
be one foot; if countesses ten inches, and so in similar proportions in regard
to other classes of slates. The lateral edges of the slate must be true, in order
to allow of butt joints being formed in the first row of size slate to be placed

page_text: on the ascending line of the roof. The duchess slate must be divided into
two parts longitudinally, which would give six inches in breadth to each part
and two feet in length, and the six inches in breadth of each part upon the
battens on the lateral side of the roof must be nailed down to the batten on
the lateral side. This is necessary to effect a bond when the upper line of
slate is placed upon it, as will be presently explained. When this is accom-
plished the lower lines of duchesses will be placed upon the battens and nailed
down, each plate abutting against the slate which is placed above it in the
centre of the battens. A sufficient area having been so sheeted the next
process is to give the sheeting so laid down a coat of thick paint or cement,
and while this coating is still soft to cover the roof with coarse paper or other
non-conductor, and pay the same over with a similar coating of paint or
cement. The process of covering the second line of the roof is then to be
commenced. It was stated above that the first line of duchess slate was to be
divided longitudinally at six inches in breadth, to be placed against the lateral
edge of the ascending line for the purpose of forming a bond, when the
upper slate should be placed upon it. The same plan must now be adopted
with the bottom line of slates. Thus the upper line of the covering slate will
on one side cover the ascending lateral line of six inches in breadth, and like-
wise abut against the lateral line of six inches in breadth at the bottom of the
roof, consequently there will be a continuous line of bonded sheeting along any
indefinite extent of the roof, it will be necessary that each edge, both at the
bottom and top of each slate, should be screwed down through the lower slate
to the batten.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Martin in the Great Seal Patent Office on the
11th October 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
MARTIN, late of Withybush, but now of Summerton, Haverfordwest, in the
County of Pembroke, Clerk, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of April, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Martin, Her special license that I, the said Thomas

page_text: Martin, my executors, administrators, and assigns, or such others as I,
the said Thomas Martin, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF ROOFS," upon the condition (amongst
others) that I, the said Thomas Martin, by an instrument in writing under
my hand and seal, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Thomas Martin, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to
the letters and figures marked thereon (that is to say) :-
This Invention consists in a novel mode of constructing slate roofs, whereby
they will not only be rendered impervious to water, but be also good non-con-
ductors of heat (an important requisite in all climates.)
To secure these advantages I form the roof covering of two layers of slate
laid evenly like flag pavement, and between these layers I interpose a layer of
good non-conducting material, and cause the same to adhere to the slates. By
this means I am enabled to form a sheet of slate of any required dimensions,
and of uniform thickness throughout.
In the accompanying Drawing, Fig. 1 shews in partial plan view a roof
constructed according to this Invention; and Fig. 2 is a longitudinal section
of the same.
a, a, a, are the ordinary rafters intended to carry the roof covering. Across
these rafters I nail down battens b, b, in lines parallel with the ridge of the
roof, and at such distances apart as will suit the size of slates employed. The
battens for ordinary roofs I prefer to make from three to four inches broad,
and when using the size of slate known as "dutchesses," I place these battens
so that the distance from the centre of one to the centre of the other will be
one foot. If the size known as "countesses" is used, the distance from centre
to centre of the battens will be ten inches, and so on for the various sizes of
slates in use. The slates must be prepared with square edges to make good

page_text: clean butt joints. The rafters having been overlaid with battens suitably
arranged for the size of slate to be employed (say dutchesses), I proceed to
cover in the roof in the following manner:-To form the first ascending line I
divide so many slates lengthwise as will suffice to extend that line from the
eaves to the ridge, and I thereby produce pieces six inches in width and two feet
in breadth. With these pieces I cover the extreme edge of the roof, fastening
down the slates to the battens by nails or screws; and I thus form the narrow
ascending line 1. This arrangement is necessary to effect a bond when the
second layer of slates is put on, as will be presently explained. When this
narrow ascending line is completed succeeding lines of undivided slates are
next placed upon the battens b, b, and nailed or screwed down side by side to
form the lines 2, 3, 4, 5, 6, &c., each slate of which abuts against that placed
above it, so as to make a butt joint therewith in the centre of a batten. A suffi-
cient area having been thus covered with slates, the next process is to apply to the
covering surface a coating of thick paint or other adhesive waterproof cement.
While this coating is still soft, or tacky I apply thereto sheets of coarse paper
or other non-conductor, such as felt, as shewn at c, c, and I pay over the same
a similar coating of paint or other adhesive cement. While this coating is still
soft I apply the second layer of slates, and to insure a good bonding I form a
lateral line by laying the slates longitudinally, as shewn at 1*, 1*, (Fig. 1.)
I then proceed with the ascending line 2*, 2*, of the covering slate, making
that line abut on the line 1*, and cover the underlying line 1, and overlap the
underlying line 2 of the first or under layer of slate. The succeeding lines of
covering slates 3*, 4*, 5*, &c., being formed of square-edged slates, as before
explained, will, by overlapping the joints of the first layer of slates, produce
bonded joints throughout the roof, and these covering slates will form close butt
joints between themselves; any defect therein being supplied by the application
thereto of the paint or cement used to effect the adherence of the interposed
material with the upper and under covering of slate. The slates forming the
covering layer I fix, as before, with nails or screws, which, passing through
holes pierced for the purpose in both layers of slates by drilling, or otherwise,
enter the intermediate battens, or those to which the underlying slates were
not previously attached.
By means of this Invention it will be understood that at a comparatively
small cost a durable and light roof covering may be obtained capable of being
set at a low pitch, if required, and which, while impervious to rain, will, unlike
metallic roofs, be a bad conductor or transmitter of heat.
Having now set forth the nature of my Invention of "Improvements in the

page_text: Construction of Roofs," and explained the manner of carrying the same into
effect, I wish it to be understood that under the above in part recited Letters
Patent, I claim constructing roofs with a compound covering, in the manner
and for the purpose above described.
In witness whereof, I, the said Thomas Martin, have hereunto set my
hand and seal, this Eighth day of October, in the year of our Lord
One thousand eight hundred and sixty.
THOMAS MARTIN. (L.S.)