[0001] The present invention relates to waterproof plates to be inserted between the tiles
and the supporting girders of a roof, to avoid that possible water seepages around
or through the tiles cause the girders to be damaged, are shaped so as to avoid or
minimize the probability of sliding of said tiles onto said plants even in the case
of highly inclined roofs. It is known since long time that the roofs covered by baked
clay tiles, especially the curved tiles, show extraordinary properties of mechanical
strength to loading and impact as well as resistance to corrosive environmental and
chemical agents.
[0002] However, in order to avoid an immediate risk of water seepage owing to exceptional
rain or th tile breakage, and also to achieve a saving of thermal energy, it is coming
customary, both in novel high class building and in the restoring of ancient or anyhow
degraded buildings, to use plates of waterproof materials, such as plates of resin
materials of the type as polyvinylchloride (PVC), acrilic-butadiene-styrene copolymers
(ABS), etc., or plates of fiber materials, such as paper board, impregnated with
bitumen, (the typical plates of bitumized paper board) to be interposed between the
covering tiles and the roof supporting structures, said plates acting as an waterproof
auxiliary roofling, adapted to prevent possible seepages of water around the integer
tiles or through perforated, cracked or anhyhow damaged tiles from reaching structural
parts of the roof, such as girders, which can be possibly damaged by said seepages,
and acting as well as a supplementary support for said tiles, the supporting capacity
of the girders being thus distributed to the whole part of the tiles which in direct
contact with said interposed plates, and lastly acting as a supplementary thermal
isolation.
[0003] As a matter of practice, for this purpose, both resin plates and bituminized paper
board plates have been provided, which gave excellent results as regards the supplementary
waterproofing given therefrom, the resin plates being preferred where a particularly
certain additional waterproofing is sought for and the cost control is not the main
problem, those of bituminized paper board being preferred in the case in which said
expenses are to be controlled.
[0004] Obviously, depending on the fact that the tiles positioned onto the roof are of planar
type or of the curved type, planar or corrugated plates shall be used, the corrugated
plates being selected with a pitch and a wave height such as to conform to the said
tiles.
[0005] One of the more serious drawbacks occurring with the use of the said undertile waterproof
plates is the risk of the sliding of the tiles onto the plates themselves, which may
occur especially in locations undergoing heavy snow falls and wherein particularly
inclined roofs are adopted , when the snow, tending to slide down from the said roofs,
does apply a tangential force downwardly directed on to the tiles.
[0006] In order to avoid such a tile sliding, systems are adopted to increase the friction
coefficient between said tiles and said undertile plates. A first system consists
in roughing by abrasion, sanding or blasting the surfaces facing towards the tiles
of the plates of resin materials.
[0007] This system does not always lead to satisfactory results since generally such a roughing
is not very deep and the irregularities as produced thereby by means of mechanical
means, especially rotating means, tend to have rounded edges by which the friction
coefficient is not increased. Moreover whatever subsequent mechancial working of finished
plates increases their cost, making them less attractive for the customers. A simpler
system consists in incorporating granulated material, such as sand, within a surface
at the time of the forming thereof, but the results, being dependent on the adhesion
of said granulated material to the said surface, are not always certain and moreover
the further processing for the embedding of said granulated materials does add to
the plate costs.
[0008] As regards the bituminized paper board plates, the roughing by abrasion is not effective
since the paper board fibres tend to form lints under abrasion and the sand addition
is of questionable effectiveness since said sand tends to be readily detached from
the bituminized paper board, the bitumen in the winter time becoming fragile owing
to the low temperatures and in the summer time becoming soft owing to the high temperatures,
whereby in any case the detachment of the sand granules is promoted.
[0009] In the prior art a solution has been proposed in order to increase the friction coefficient
of bituminized paper board plates by using plates manufactured by the so-called "planar
table", namely a system in which the paper board is manufactured by filtering paper
pulp through a net leaving an impression thereof onto the paper board plate having
a moderate anti-sliding effect in the downwardly direction.
[0010] Another solution according to the prior art consists in passing the paper board plates,
still in the moistened condition, before their entry in the drying section, through
a roller pair, one of which has a knurled surface leaving onto one surface of said
paper board plate an impression similar to that of the net in the planar table.
[0011] The more serious drawback shown by the aforesaid solutions according to the prior
art consists in that the net or the knurling generates impressions which are not
perpendicular but inclined according to an angle different from 90⁰ with reference
to the laying of the tiles to be laid down, onto the plate and moreover with rather
rounded corners whereby the antisliding effect of said impressions is rather moderate.
[0012] The purpose of the present invention is that of providing undertile waterproof plates,
both of planar and of corrugated type, shaped so as to avoid the sliding of the tiles
especially in roofs with highly inclined sides.
[0013] Another purpose of the present invention is that of providing undertile waterproof
plates of thermoplastic resin materials.
[0014] A third purpose is that of providing said waterproof plates of bituminized paper
board.
[0015] The aforesaid and other purposes of the present invention are achieved by forming
undertile waterproof plates having essentially rectilinear scoring or depression,
with clean edges and oriented perpendicularly to rows of tiles to be laid down onto
the plates themselves.
[0016] According to a particular embodiment, said scorings have rectangular profile.
[0017] According to another particular embodiment, said scorings have triangular profile.
[0018] According to a further embodiment said scorings have serrated profile.
[0019] According to a particular embodiment, said plates are formed by thermoplastic material.
[0020] According to a more particular embodiment, said thermoplastic material is polyvinyl
chloride (PVC).
[0021] According to another more particular embodiment, said thermoplastic material consists
of acrilic-butadiene-styrene copolymers (ABS).
[0022] According to a preferred embodiment, said plate of thermoplastic material, if of
the planar type, is manufactured by means of an extruder having an extruding die shaped
as a slot with a rectilinear major side and the opposite major said of tortuous shape.
[0023] According to another preferred embodiment, said plate of thermoplastic material,
if of corrugated type, is manufactured by corrugating a planar plate with a second
face as above defined.
[0024] According a further embodiment, said plates of bitumen impregnated paper board of
planar type are provided with scorings perpendicular to the rows of tiles to be laid
down onto the plates themselves, while still in the moistened state and before being
impregnated with bitumen, by means of a roll scored parallely to the generating line
thereof pressing the paper board plates against another smooth roll.
[0025] According to an alternative embodiment, said plates of bitumen impregnated paper
board, of corrugated type, are provided with scorings perpendicular to the generating
lines of these corrugations, by impressing said scoring onto a face of said paper
board plates of planar type, while still in the moistened condition and before being
bituminized, by means or a roller scored parallely to its generating lines, as above
described, and subsequently carrying out the corrugation of the paper board, still
moistened, between other roller pairs.
[0026] According to a preferred embodiment, said plates of bitumen impregnated paper board,
of planer type, are scored by manufacturing said paper board from a moistened paper
pulp laid down onto a roller scored along its generating lines, in order to obtain
scorings perpendicular to the direction of the paper fibers and so that the paper
fibers nearest to the roller are positioned according to the scorings of said roller
and subsequently are positioned in a manner less and less tortuous until they take
a smooth pattern, whereby the surface of the paper board facing the scored roller
is scored, whereas the opposite surface is smooth.
[0027] According to an alternative embodiment, said plates of bitumen impregnated paper
board, of corrugated type , are firstly scored at one surface by manufacturing said
paper board from a moistened paper pulp, according to the above described method,
leading to scorings perpendicular to the plate forming direction and to the direction
of the paper fibers, and then by corrugating said just formed paper board, still moistened,
according to corrugations having generating lines perpendicular to said scorings
onto one surface.
[0028] The aforesaid features and advantages of the present invention, together with other
advantages and features, shall be better understood from the detailed description
of the preferred embodiments thereof referred to in the accompanying drawings wherein:
- figure 1 is a perspective view of a portion of Roman roof with roof tiles laid down
onto scored undertile plates of planar type according to the invention;
figure 2 is a perspective view of a portion of roof with curved tiles laid down onto
scored undertile plates of corrugated type still according to the invention;
figure 3A is a cross-section, seen sidewise, of the roof of figure 1, taken along
the line III-III, particularly representing a planar undertile plate, having cross
scorings with rectangular profile, and the anchoring action thereof with respect
of the abutting tiles;
figure 3B is a cross-section view, as seen sidewise, of the roof of figure 1 , taken
along the line III-III, particularly representing a planar undertile plate, having
cross scorinsg with serrated profile, and the anchoring action thereof with respect
to the abutting tiles;
figure 4A is a cross-section, as seen sidewise, of the roof of figure 1, taken along
the line IV-IV, particularly representing a corrugated undertile plate, having cross
scorings with rectangular profile, and the anchoring action thereof with respect to
the abutting tiles;
figure 4B is a cross-section view , as seen sidewise, of the roof of figure 2, taken
along the line IV-IV, particularly representing a corrugated undertile plate, having
cross scorings with serrated profile, and the anchoring action thereof with respect
to the abutting tiles;
figure 5 schematically illustrated a method and apparatus for the manufacturing of
scored planar plates of thermoplastic material;
figure 6 schematically illustrates a detail of an apparatus for the manufacturing
of paper board planar plates with scorings having rectangular profile;
figure 7 is an enlarged cross-section view of a portion of a paper board planer plate,
with rectangular profile scorings adapted to illustrate the disposition of the fibers
in the plate itself;
figure 8 schematically illustrates a detail of an apparatus for the manufacturing
of paper board planar plates with scorings having triangular or serrated profile;
figure 9 is an enlarged cross-section view of a portion of a planer paper board plate,
with triangular or serrated profile scorings, adapted to illustrate the disposition
of the fibers in the plate itself.
[0029] Referring to figures 1, 3A and 3b, a Roman roof 10 is seen as formed by roof tiles
12, the junctios of which are covered by curved tiles 14, the roof tiles 12 abutting
onto scored undertile plates of planar type 16. The scoring of said undertile plates
may have whatever profile useful to prevent the tiles from sliding, such as rectangular,
trapezoidal, triangular, serrated or like profiles, the profile illustrated in figure
3A being rectangular and that shown in figure 3A being the particular type of triangular
profile known as serrated profile.
[0030] As shown in figures 3A and 3B, the undertile plates, which are therein respectively
indicated as 16a and 16b , are abutting onto a girder or slab 18 by which they are
supported, the plate 16a having rectangular ribs 17 alternating with the depressions
19, the plate 16b having serrated ribs 17b.
[0031] Referring to the figures 2, 4A and 4B, it is seen that a roof with tiles 20 comprises,
as it is known since very long time, curved tiles 22, the channel is which of upwardly
facing, and curved tiles 24 having the channel facing downwardly, the curved tiles
22 with the channel facing upwardly being abutted against scored undertile plates
of corrugated type 26. The scoring of said undertile plates may have whatever profile
useful to prevent the tiles from sliding, such as rectangular, trapezoidal, triangular,
serrated or like profile, the profile illustrated in the figure 4A being rectangular
and that shown in the figure 4B being the particular type of triangular profile known
as serrated profile.
[0032] As shown in the figures 4A and 4B the undertile plates which are therein respectively
indicated by 26a and 26b are supported onto a slab or girder 28 by which they are
supported, the plate 26a showing rectangular ribs 27a alternating with depressions
29 and the plate 26b having serrated ribs 27b.
[0033] The action of the planar undertile plates 16a and 16b, figures 3A and 3B is illustrated
hereinafter.
[0034] The roof tiles 12 abut against said undertile that 16a of figure 3A with the upper
edge restrained in a depression 19 between two ribs 17a.
[0035] An accidential displacement of one of said tiles to the position 12′, shown by dash
and dot and lines in figure 3A, causes the upper edge of said tile to be more deeply
fixed within a depression 19′ which is adjacent or anyhow close to the depression
19 it which is was originally fixed, it moreover pressing with a greater force and
further pushing against the rib 17a which is immediately adjacent, with attendant
great increase of the friction coefficient between the tile and the undertile plate
preventing any further sliding of the tile itself.
[0036] In a fully similar manner the planar tiles 12 abut against said undertile plate 16b
of figure 3B with the upper edge fixed between two serrated adjacent ribs 17b and
more particularly with the edge abutted against the less inclined profile of one of
said ribs and the immediately adjacent edge area abutted against the upper edge of
the immediately next rib. An accidental displacement of one of said tiles to the position
12′, shown by dot and dash lines in the said figure 3B, causes the upper edge of said
tile to more deeply fix within the less inclined profile of a close rib 17b′ and immediately
adjacent edge area to press with a greater force and to further push onto the upper
edge of the immediately next rib 17b˝, with the attendant great increase of the friction
coefficient between tile and undertile plate preventing any futher sliding of the
tile itself.
[0037] The action of the corrugated undertile plates 26a and 26b of figures 4A and 4B is
illustrated hereinafter.
[0038] The curved tiles 22 abut onto said undertile plate 26a of figure 4A with the upper
edge restrained in a depression 29 between two ribs 27a. An accidental displacement
of one of said tiles to the position 22′, illustrated by dash and dotted lines in
figure 4A causes the upper edge of said tile to be more deeply restrained in the depression
29′ adjacent or anyhow close to the depression 29 in which it was originally restrained,
pressing moreover with a greater force and pushing against the rib 27a which is immediately
adjacent, with the attendant great increase of the friction coefficient between the
tile and the undertile plate, by which any further sliding of the tile itself is prevented.
[0039] In a fully similar manner, the curved tiles 22 abut onto said undertile plate 26b
of figure 4B with the upper edge restrained between two adjacent serrated ribs 27b
and more particularly with the corner abutting onto the less inclined profile of one
of said ribs and the edge area which is immediately adjacent abutted onto the upper
edge of the immediately next rib.
[0040] An accidential displacement of one of said tiles to the position 22′, illustrated
by dash and dot and lines in figure 4B, causes the upper edge of said tile to be more
deeply fixed within the less inclined profile of a near rib 27b′ and the immediately
adjacent edge area to press with a greater force a two further push against the upper
edge of the immediately adjacent rib 27b˝, with the attendant great increase of the
friction coefficient between the tile and under tile plate preventing the tile itself
from any further sliding.
[0041] Turning now to consider figure 5, detail of an extrusion apparatus is illustrated
suitable for the manufacturing of planar plates of thermoplastic material such as
PVC, ABS and the like. Said extruder 100 comprises a die or extrusion mold 110 having
a tortous upper edge, which in the shown example is shown as rectangular profile but
may have any other profile useful in the production of cross scorings, and with a
straight lower edge. From said die 100 a scored plate 116 is extruded which is pushed
onto a conveying table comprising two supporting posts 112 which support idle rollers
114 permitting the forwarding of said plate 116.
[0042] As it can be seen in said figure 5, the plate 116 is provided with scorings oriented
in the extrusion direction indicated by the arrow 115, comprising protruding ribs
117 and depressions 119, all of retangular profile.
[0043] Obviously, as above stated, the profile of said scorings may be different and, particularly,
may be the serrated profile shown in figure 3B It is also obvious for the skilled
person how from said planar plate 116 a corrugated plate can be obtained by using
a corrugating machine.
[0044] The scored plates of bituminized paper board, both planar and corrugated, even if
they do not show properties of strenght of moisture resistance comparable with those
of the plates of thermoplastic materials, are however very interesting owing to their
very reduced costs, owing to their very low fragility and to the optimum friction
coefficient which can be obtained with said scoring.
[0045] Said scoring may be provided in several manners among which the preferred ones are
the use of a scoring machine formed by two rollers one of which has a planar cylindrical
surface to rearwardly support a wetted paper board and the other has a scored surface
in the direction of the generating lines with scorings of square, rectangular, triangular
of serrated section to press and impress and scoring of the plate.
[0046] The two cylinders may be spaced in adjustable manner from each other, whereby an
impression more or less deep can be impressed.
[0047] This method of scoring by impression onto wet paper board has however the drawback
that, owing to the subsequent drying of the paper board the impressions tend to level
owing to the fact that, as it is believed, the fibers of wet paper board, bend for
the impression and to straighten owing to the drying and consequently to provide
a scoring having a given dry deepness, a much more deep scoring must be impressed
in the wet state, sometimes in the proximity of the brecking limit of the paper board
itself.
[0048] In order to avoid this drawback of the poor deepness of the scoring or of possible
bracking of the paper board, the systems, respectively illustrated in figures 6 and
8 have been proposed, giving as results sheets or plates of paper board of the type
illustrated in the figures 7 and 9 respectively.
[0049] By considering figure 6, it is seen that in order to form a sheet of scored paper
board a felt belt 130 is passed, moving according to a direction 132 and carrying
a layer of paper pulp 134, under a roller 136 with rectangular scoring by which the
pulp of the layer 134 is detached from the felt 130 and accumulated onto said roller
136 to form a layer in form of a cylindrical endless sheet 138.
[0050] The fibres of paper pulp, having a length much less than the spacing between the
scorings of the roller 136 at the and beginning are positioned so as to follow said
scoring namely following their contour. As the thickness of the cylindrical endless
sheet 138 increases , the fibers are positioned according to a more and more regular
and smooth pattern until said scorings are no longer followed.
[0051] The roller 136 during the rotation does continuously accumulate paper pulp until
a required thickness is achieved, and at that time a blade 140, housed within a cavity
142, comes out cutting the cylindrical endless sheet 138 which is thus opened and
detached from the roller 136 it being removed by means of a sliding table (not shown)
for the conveying to a further drying.
[0052] As it can be more particularly seen in figure 7, the sheet of fresh paper board 116a,
which on one side has a scoring form by protruding ribs 117a and depressions 119 is
formed by a plurality of layers 120-128 in which the fibers of the upper layers 120-123
follow in a progressively less marked manner the said scoring and those of the layers
124-128 are essentially smooth as the lower surface of said sheet.
[0053] By considering figure 8, it is seen that in order to form another type of scored
paperboard sheet a felt belt 150, moving alone a direction 152 and conveying a layer
of paper pulp 154, is passed under a roller 156 having a scoring of the so-called
serrated shape, by which the pulp of the layer 154 is detached from the felt 150,
it being accumulated onto said roller 156 to form a cylindrical endless sheet 158.
The fibers of paper pulp, having length much less than the space between scorings
of the roller 156, are initially positioned according to said scorings namely following
their contour. As the thickness of the cylindrical endless sheet 158 increases, the
fibers are positioned according to a more and more regular and smooth pattern until
said scorings are no longer followed.
[0054] The roller 156 during the rotation continuates to accumulate paper pulp until a required
thickness is achieved , and at that time a blade 160 housed in a cavity 162 comes
out cutting the cylindrical endless sheet 158 which is opened and detached from the
roller 156, it being removed by means of a sliding table for the forwarding to the
further drying.
[0055] As it is more particularly seen in figure 9, the sheet of fresh paper board 116b
which on one side has a scoring formed by serrated ribs 117b, is formed by a number
of layers 163-170 in which the fibers of the layers 163 and 166 follow in a lesser
and lesser marked manner said scorings and those of the layers 167-170 are essentially
smooth as the lower surface of said sheet.
[0056] Of course, both the sheet of paper board 116a and the sheet 116b can be dried in
a planar form or, before the final drying, may be passed through a corrugating machine
by which a corrugation perpendicular to the direction of their scorings is given.
[0057] The above described and illustrated embodiments of the present invention are preferred
ones, given merely for exemplifying and non limiting purpose, and the skilled in
the art shall realize totally or partially equivalent solutions with respect to those
above mentioned which are obviously herein covered.
1. Waterproof plates, to be interposed between the tiles and the girders of a roof
in order to protect said girders from possible water seepage, particularly to minimize
the possibility of sliding of said tiles onto said plates, by increasing as much as
possible the friction coefficient between said tiles and said plates, characterized
in that in order to increase said friction coefficient said plates are provided with
scorings or depressions, which are essentially rectilinear and with clean edges and
are positioned perpendicularly with respect to rows of tiles to be placed onto the
plates themselves.
2. Waterproof plates according to claim 1, characterized in that said scorings have
rectangular profile.
3. Waterproof plates according to claim 1, characterized in that said scorings have
trapezoidal profile.
4. Waterproof plates according to claim 1, characterized in that said scorings have
triangular profile.
5. Waterproof plates according to claim 1, characterized in that said scorings have
serrated profile.
6. Waterproof plates according to claims 1-5, characterized by being formed of thermoplastic
material .
7. Waterproof plates according to claim 6, characterized in that said thermoplastic
material is polyvinyl chloride (PVC).
8. Waterproof plates according to claim 6, characterized in that said thermoplastic
material is an acrylic-styrene-butadiene copolymer (ABS).
9. Waterproof plates, according to claims 6-8, characterized in that, if of planar
type, their manufacturing takes places by means of an extruder having an extrusion
die in form of a slot having a rectilinear major side and the opposite major side
of tortuous shape.
10. Waterproof plates, according to claim 9, characterized in that said plates of
thermoplastic materials, if of corrugated type, are manufactured by corrugating planar
plates having a scored surface.
11. Waterproof plates according to claims 1-5, characterized by being formed by fiber
materials, such as paper boards, impregnated with bitumen.
12 Waterproof plates, according to claim 11, characterized in that said bitumen impregnated
paper board plates of planar type are provided with scoring perpendicular to the rows
of tiles to be laid down onto the plates themselves by impressing said scorings onto
a surface of the plate themselves still in the moistened state and before being bituminized
, by means of a roller which is scored parallely to its generating lines pressing
the paper board plates against another smooth roller.
13. Waterproof plates of bitumen impregnated paper boards of corrugated type, provided
with scorings perpendicular to the generating lines of said corrugations, obtained
by impressing said scoring in surface of a planar type paper board plate, when the
paper board is still in the moistened condition and before being bituminized, by means
of a roller scored parallely to its generating lines, as described in claim 12, characterized
in that the paper is subsequently corrugated, it being still in the moistened stated,
between other pairs of rollers.
14. Waterproof plates, according to claim 11, characterized in that said bitumen impregnated
paper board plates, of planar type, are scored by manufacturing said paper board from
a wet paper pulp which is laid down onto a roller scored along its generating lines,
to obtain scorings perpendicular to the direction of the paper fibers and so that
the paper fibers closests to the roller are laid according to the scorings of said
roller and subsequently are positioned in a less and less tortuous manner until a
smooth pattern, is taken , whereby the surface of the paper board facing towards the
scored roller is scored whereas the opposite surface is smooth.
15. Waterproof plates of bitumen impregnated paper boards of corrugated type, which
are firstly scored onto a surface by manufacturing said paperboard from a wet paper
pulp according to the method of claim 14, thus obtaining scorings perpendicular to
the direction of forming of the plates and to the direction of the paper fibers, characterized
in that said paper board, once formed and still moistened, is thereafter cor rugated
with corrugations having generating lines perpendicular to said scorings onto one
surface.