[0002] The roof of a building is one of the most complex and intricate parts of any structure.
Recently, however, the simple protective action of a roof has been supplemented with
other functions, so that it has become not only a substantial feature of the appearance
of the whole building but also an essential factor in the safety, the soundproofing,
and especially the thermal insulation of the building. It is this insulating function
that has been the main subject of continuing intensive research in recent years. As
is well known, this insulating function of the roof of any building is the focal point
of the energy savings relating to the building and the associated economic considerations.
The proper insulation of the roof prevents a building from unnecessarily dispersing
a large proportion of the heat produced in the home into the external environment.
To prevent this large heat loss, a considerable number of products and installation
methods are now available on the market; these all tend to create a more or less airtight
seal of the roof itself and also the whole area immediately below it. Although this
insulation by sealing drastically reduces the loss of internal heat into the environment,
it also prevents the physiologically essential air exchange in the roof and in the
sub-roof area. The total or partial absence of ventilation in the whole upper area
of the building inevitably promotes the accumulation and condensation of moisture
in the structural voids of the roof and the sub-roof area, leading to the degeneration
of the organic materials forming the structures and to water infiltration.
[0005] The essential principle of the present invention is the creation of a dry ventilated
air chamber (1) between the upper part of the roof (A and B) and the underlying tar
or fibre skin (4) which covers the thick layer of insulating material (5) positioned
immediately below it. Within the said air chamber (1), air circulation is made possible
by thin flat strips (6a, 6b, 6c) whose structure in the form of broken curves creates
wide slots (10, 11, 12) allowing a substantial body of air from the outside to rise
and enter the gap (1) between the two sloping surfaces (A and B) which are combined
to form the roof. The said air circulation takes place without any associated passage
of water, which, as is well known, is heavier than air and therefore cannot rise through
the slots (10, 11, 12) which have been suitably created between the adjacent strips
(6a, 6b, 6c). The selective and exclusive passage of air between the slots (10, 11,
12) is due to the specific profile formed by the single strips (6a, 6b, 6c) when they
are placed regularly above each other to fill the whole space (D) separating the two
sloping surfaces (A and B) which are combined to form the roof. These strips (6a,
6b, 6c) are made from aluminium or any other metal alloy or plastics, in such a way
that they are rigid and strong enough to have a limited supporting action in addition
to the aforesaid action of selectively blocking the space (D) between the levels of
the two surfaces (A and B). The strips (6a, 6b, 6c) are of three different types.
A first type, called (6a), is positioned above the others and is substantially a metal
or plastics section, provided with a large upper edge (6a1) which is approximately
as long as the tile (2) used in the roof to be constructed. The tile (2) is supported
and fixed by screws or nails in its lower part on the upper face of the surface (6a1)
of the said strip, and the remote end (6a2) of the said strip is wrapped around the
lower edge (8) of the tile for a length of about two centimetres. The turned-over
edge (6a2) of the strip (6a) is provided with a set of holes, each having a diameter
of about two centimetres and positioned about five centimetres from each other, to
allow the run-off of the rainwater collected by the tile (2) when precipitation occurs.
The shape of the opposite end of the strip (6a) includes two acute angles (6a3 and
6a4) which cause it to be practically folded back on itself. The said upper strip
(6a) is fastened to the underlying tile (2) by a number of nails or screws applied
to the flat surface (6a1) and is fixed to the underlying strip (6b) by means of the
supporting bracket (7) which in turn is fastened at its upper edge (7a) to the lower
face of the surface (6a1) by a weld, by ordinary screws or by rivets which are suitably
insulated to prevent water infiltration. A second type of strip (6b) fills the space
(D) between the two oblique flat surfaces (A and B) which are combined to form the
roof. As the number of type 6b strips stacked on each other increases, the underlying
air chamber (1) becomes higher and more spacious. The number of strips 6b can range
from one to eight, although there are preferably three strips, each of which is essentially
composed of a metal or plastics section having an upper end (6b3 and 6b4) identical
to that of the strip 6a, and a rear profile (6b1) only three centimetres in depth
and rising vertically (6b2) by the same amount from the angle 6b3. The vertical portion
(6b2) is formed to enable the flat rear part (6b2) of the strip 6b to be fixed to
the vertical supporting bracket (7). The vertical supporting bracket (7) has a height
equal to the distance (D) between the two oblique surfaces (A and B) which form the
roof, a width of about five centimetres, and a thickness of about one centimetre.
The said supporting brackets (7) are screwed, welded or riveted to the rear sides
of the strips (6a, 6b, 6c) at a distance of about 60 centimetres from each other,
but their spacing can vary from 20 to 90 centimetres from each other if necessary.
The thickness of the strips (6) can vary from 0.5 to 1.5 centimetres, but the optimal
thickness is 0.62 centimetres. The total length of the strips (6a, 6b, 6c) varies
from 0.5 to 6 metres, and the optimal length of each individual strip is therefore
four metres. The third type of strip (6c), which is positioned under the other two
(6a and 6b), is provided with a vertical part (6c2) about three centimetres high,
the back of which is fixed to the bracket (7), and is provided with an angle (6c1)
so that it extends frontally for about 10 centimetres before being folded on to itself
at the point 6c4 in order to grip a sheet of lead which extends for about 10 centimetres
on top of the first upper tile (9) of the lower inclined surface (B) of the roof.
The aforesaid system of strips (6) creates protected spaces (10, 11, 12) through which
the atmospheric air can rise freely, enabling the whole sub-roof area (1) to be ventilated
continuously, thus preventing the formation of condensation both under the roof itself
and within the air chamber (1) created. However, the heat in the building is held
inside by the insulating material (5) which is positioned on the lower part of the
air chamber (1). To prevent leaves, small animals or insects of various kinds from
nesting in or infesting the ventilated void (1), a narrow-mesh net is provided for
fitting on the rear of the brackets (7) to allow the passage of air only. The aforesaid
invention is applicable to any sloping roof having a plurality of oblique surfaces
with inclinations in the range from 15 to 70 degrees. However, the optimal angle is
considered to be in the range from 18 to 25 degrees.
