Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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~oofing-material.
The inVntion relates to a roofing-material provi-
ded with perforations and compri6ing a bituminized carrier
with a non-sticking lower surface and destined for being ap-
plied on a substratum and for being covered by an upper lay-
er, which may contain a carrier which is bi~uminized withmodified bitumen, and which may be applied by means of a
torch .
With a known roofing an under-layer is laid on a
substratum consisting for instance of a covered plastic foam,
10 such as polystyrene foam or polyurethane foam, or of an old
existing roofing. This under-layer consists of the roofing-
material of the type described hereinabove and is composed of
glass fibre mat, which is bituminized with blown bitumen and
which has a non-sticking surface on one side and is provided
15 with small perforations with a diameter of about 1,5 cm, which
together take up about 4~ of the total surface.
The under-layer is fixed to the substratum at the
location of the roof-edges over a width of about 2 metres
with an adhesive layer of blown bitumen, which has first been
20 liquefied in a bitumen-heater and which is applied in a
sine-shape generally hy means of a can.The roofing-material
which forms the under-layer is not fixed to the remaining
part of the substratum.
Subsequently an extra coat of blown bitumen is ap-
25 plied on the roofing-material forming this under-layer, which
bitumen has also been liquefied beforehand in a bitumen-
heater, whereby the liquid bitumen locally adheres to the
substratum through the perforations in the under-layer.
Thereupon an upper layer, for example consisting
30 of bituminized polyester mat, wherein the bitumen is modified
with atactic polypropylene, is applied by means of a propane
torch or burner or the like on the whole surface of the
under-layer with staggered cross-overlappings, whereafter the
overlappings are checked and are after-treated, if necessary.
35 The coating of modified bitumen at the lower side of this ~at
may be thicker than the coating of modified bitumen on the
upper side of the mat.
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This known roofing in itself has been very satis-
factory, but nevertheless it still has several disadvanta-
ges.
Although the upper layer is applied by means of
the torching-method, 60 that for this purpose the use of the
bitumen-heater,which is in fact very objectionable, is not ne-
cessary, this bitumen-heater is yet required with the known
roofing for applying the above-mentioned adhesive layer for
fixing the under-layer at the location of the roof-edges, as
10 well as for the application of the extra coat, so that the
advantage of the use of the torching-method for applying the
upper layer is lost again for the greater part.
Further the adherence through the perforations in
the under-layer amounts only to about g%, so that the above-
15 mentioned additional fixation of the under-layer along the
roof-edges is necessary.
Furthermore the roofer has, especially in summer,
a lot of hindrance of the extra coat, which remains sticky
during a long time, so that walking on it is rather diffi-
20 cult.
An important disadvantage connected with the knownroofing-material consists in that the extra coat, which has
to be applied in liquid condition cannot consist of modified
bitumen, as this would make too high demands upon the bitumen-
25 heater.
Therefore this extra coat consists of a blown bi-
tumen, while the roofing-material forming the perforated un
der-'ayer is made with the application of blown bitumen as
well. Since modified bitumen has much better characteristics
30 than blown bitumen, it is of course unfavourable for the qua-
lity of the complete roofing when the same can only be parti-
ally made of modified bitumen.
It is an object of the present invention to fur-
ther develop the roofing-material of the type mentioned here-
35 inbefore to such extent that the objections mentioned abovewill be removed in an efficient manner and that it will be
possible to use modified bitumen for the complete roofing.
For this purpose the roofing-material according
to the invention i6 characterized in that the carrier of
_ 3 _
the rooling-material is bituminized with modified bitumen,
and the perorations are ~o large that the upper layer can be
directly applied on t}le roofing-material by means of a torch
and can be adhered to the substratum via the perforations.
According to the invention the perforations in the
under-layer formed from the roofing-material have such dimen-
sions,that the upper layer can be applied by means of a torch
and can yet locally be adhered to ~he substratum via these
perforations without the application of an extra coat. With
10 the roofing-material according to the invention it is no
longer necessary to fix this material on the substratum at
the location of the roof-edges, as the adherence between the
upper iayer and the substratum via the larger perforations is
sufficiently strong.
Because the perforations in the under-layer formed
from the roofing-material according to the invention are fil-
led with modified bitumen, it will be remunerative to also
use modified bitumen when manufacturing this roofing-mate-
rial. In this way it is achieved that exclusively modified
20 bitumen is used for the complete roofing.
As both the adhesive layer of blown bitumen be-
tween the under-layer and the substratum at the location of
the roof-edges and the extra coat of blown bitumen have be-
come superfluous, it is no longer necessary to use a bitumen-
25 heater, and the whole roofing can be applied by means of thetorching-method.
Preferably with the roofing-material according
to the invention forming the under-layer the coating of modi-
fied bitumen lying above its carrier is thicker than the
30 coating of modified bitumen lying underneath its carrier.
In this way a large guantity of melted bitumen
is obtained during the application of the torch, so that a
good adherence with the upper layer, as well as, via the per-
forations, with the substratum, is accomplished, whilst fur-
35 ther a buffer is formed against the heat of the propanetorch. In this manner it is prevented that the parts between
the perforations of the roofin9-material, which form the un-
der-layer, would be heated to such an extent that an ~ninten-
ded adherence to the substratum would take place.
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~ ith this measure, in combination with the appli-
cation o the non-sticking surface at the lower side o the
under-layer ormed from the roofing-material according to the
invention, an adherence to the substratum outside of the
perforations is avoided, so that no formation of blisters
between the under-layer and the substratum can occur.
The perforations in the roofing-material according
to the invention may have a smallest inner dimension of 50-
110 mm and preferably of about 70 mm.
In this case the degree of perforation of the
roofing-material according to the invention may be 8-14% and
preferably about 11%.
Advantageously the roofing-material according to
the invention comprises bit~minized perforated glass fibre
15 mat, wherein the bitumen is modified with atactic polypropy-
lene or a styrene-butadiene-styrene co-polymer.
~urther the roofing-material according to the in-
vention may have the form of a strip, which has a thinned
selvage at one longitudinal side.
In this way it is prevented that the overlappings
of adjacent strips would become too thick.
The invention will be elucidated hereafter with
reference to the drawing.
Fig. 1 is a partial top view of several adjacent
25 strips of the roofing-material according to the invention.
Fig. 2 is a section along the plane II-II in fig.
1 on a large. scale.
The drawing shows a number of strips 1 formed from
the roofing-material according to the invention, which are
30 used as the under-layer of a roofing. These strips 1 may
be delivered in the form of rolls and are applied on a sub-
stratum 2,which for instance consists of covered plastic foam
like polystyrene foam, polyurethane foam or the like, or of
an old roof ing.
The strips 1 each consist of a carrier 3 bituminized
with modified bitumen 4, and provided at the lower side with
a coat of fine gravel 5 applied during the manufacture of the
strips. As an alternative for the gravel 5 another type of
non-stlcking material, such as a plastic foil may be used.
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The strips 1 o~ roofing-material according to the
invention,which form the under-layer,are provided with perfo-
rations 6, having a diameter of 50-110 mm and preferably of
about 70 mm, while the degree of perforation is ~-14~ and
preferably about 11~.
With advantage the strips 1 may comprise a bitumini-
zed perforated glass fibre mat,wherein the bitumen is modified
with an atactic polypropylene or a styrene-butadiene-styrene
co-polymer.
With the strips 1 of the roofing-material accor-
ding to the invention the coating of modified bitumen 4' ly-
ing above ~he carrier 3 is thicker than the coating of modi-
fied bitumen 4'' lying underneath the carrier.
At one longitudinal side each strip 1 of the roof-
15 ing-material according to the invention has a thinned selvage
7 without gravel.
For constructing the complete roofing first a
number of strips 1 are laid on a substratum 2 which strips
are formed from the roofing-material according to the inven~
20 tion and are serving as an under-layer. As appears from figs.
1 and 2, the selvage 7 always overlaps the adjacent strip 1.
Hereafter the strips of the upper layer (not shown)
each consisting of a carrier bituminized with modified bitu-
men, for instance o bituminized polyester mat, wherein the
25 bitumen is modified with e.g. an atactic polypropylene, are
applied by means of the torch on the roofing-material accor-
ding to the invention which forms the under-layer.The coating
of modified bitumen underneath the mat is thicker than the
coating of modified bitumen above the mat. The strips of the
30 upper layer locally adhere to the substratum via the perfora-
tions 6 in the roofing-material which forms the under-layerO
The roofing-material according to the invention
has important advantages.
In the first place the adherence to the substratum
35 is at least three times as strong as with the known roofing-
material, so that no additional adherence along the roof-ed-
ges is necessary anymore.
Further, due to the larger dimensions of the per-
forations in the roofing-material according to the lnvention
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the upper layer can be adhered to the substratum by means of
the torching-method, so that the use of a bitumen-heater is no
longer necessary and the application of the complete roofing
can be realized very quic~ly.
Since the extra coat between the under-layer and
the upper layer has become superfluous, the roofing may be ap-
plied without any objection even if the weather is very warm.
A further important advantage obtained according
to the invention consists in that for the construction of the
10 roofing only modified bitumen and no blown bitumen is used.
The invention is not restricted to the embodiment
shown in the drawing by way of example which may be varied in
several ways within the scope of the appended claims.
