Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The presellt invention relates to an external
racing ~or roofs, ~alls and the like for buildings to be
mounted in form of overlapping or butt jointed e]ements
or slabs on a non-water ti~ht underlayer and with an in-
clination in order drain off the precipitation.
Facings for buildings of this type as a rule
consists of a hard and impermeable material, which is
waterproof and substantially airtight. Preferred materials
are metal, tile or asbestos.
These~aterials have some disadvantages where they
are used without an inside insulation, which insulation
is able to prevent a large transmission of heat, or prevent
condensation of water on the inside of the facing. In
non-heated storehouses, garages and similar buildings
comprising a simple construction with walls consisting of
only the layer forming the shield against the rain, con-
densation of water causes considerable problems and dripping
water causes serious damage to goods or machines stored
in the building.
The object of the present invention is to provide
an external facing of the type referred to above, by which
the above disadvantages are diminished.
This object is obtained with a facing consisting
of a mineral wool containing a bonding agent and with the
fibres oriented substantially paraIlel with the outside
surface at least in a layer adjacent to this surface.
The invention is based on the observation that min-
eral wool containing a bonding agent and witn the fibres
oriented substantially parallel with the surface is im-
permeable to rain and other forms of precipitation. The
outside surface to a depth of a couple of millimeters
will weather and the bonding agent partly decompose, but
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ullder th;s surrace layer the mineral wool will stay intact
and keep its water repellant properties because of the pro-
tection prov:ided by the weathered surface. The mineral wool
being permeable to air and vapour will prevent condensation
taking place and the disadvantages referred to above will
not be present with the facing according the invention.
As a consequence for instance a roofing may be completely
solid without the normal ventilation on the inside of the
facing and therefore constructed without the normal laths
and rafters, which means that the facing on the roof is part
of the heat insulation of the building. This feature further
makes the construction impermeable to snow as there is no
ventilated hollows into which the snow may find its way.
As such the facing also is impermeable to snow as it may be
mounted with tight seams, for example by gluing. Because
of the elasticity of the mineral wool a plastic sealant
is not necessary in the seams. Further due to the low
heat transmission a good insulation is obtained. The or-
ientation of the fibres substantially parallel with the sur-
face makes the weathering of the mineral wool a slow process
and substantially prevents and capillary action into the
thickness of the mineral wool. The use of mineral wool
as a facing provides a possibility of an additional in-
sulation obtained in a simple way as the new facing may be
mounted on top of the original one.
The invention is described in details in the follow-
ing with reference to the drawings, showing examples of
building constructions with the external facing according
to the invention.
Fig. 1 shows a section through part of a roof in a
building faced with slabs of mineral wool, and
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Fig. 2 shows a section -through a house, which is
provided with an ad(iitional insulation.
Fig. 1 shows a building which has no insula-tion
apart from the insulation provided by the rainproof external
facing. The building comprises vertical studs 1 and rafters
2, supporting and carrying a faclng 3 for the walls and a
roofing 4 respectively. The roofing 4 is fixed for example
by means of nails 5 with washers under the heads of the nails
to beams or laths 6, running perpendicular to the posters or
rafters. The roofing is made from overlapping slabs 7 of
mineral wool containing a bonding agent, the fibres of the
mineral wool being oriented in directions substantially paral-
lel with the surface. The orientation of the fibres may be
the same throughout the thickness of the slab or the slab may
have a core with strips with the fibres oriented in planes
perpendicular to the surface. At the over]apping slabs may
have grooves 8 in order to reduce the thickness of the over-
lap. The upper slab may be glued to underlaying slab, but
may also be fixed by other means, for example pins fixed to
the nails, which pins protrude into the endface of the slab. ~ ~
The wallfacing may be constructed as the roofing
but may also be constructed as shown with drip caps 9 of metal
or plastic profile.
The slabs 3 normally will continue to the underside
of the roofing, at which point ventilation is unnecessary due
to the vapourper~eability of the mineral wool facing
Fi~. 2 shows a section through a part of a house with
further internal insulation. On laths 10 a roofing 11 com-
prising slabs with a tapering profile is fastened for example
by glueing. This makes an overlapping at 12 possible in add-
ition to the obtention of a plane internal surface 13. Add-
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itiona1 ills~ iol1 14 lherefore may be placed closely ad-
jacel1~ to the rooring slabs without empty spaces, which owing
to the air permedbility of the mineral wool w:ill tend to
reduce the total insulation capacity of roofing and insul-
ation.
If it is necessary to provide a membrane imper-
meable to air or vapour this membrane should be placed
closely adjacent to the inside of the interior face of the
insulation, which face, in case of the facing being the only
insulation, is inner face of -the facing. The air- or vapour-
imperme2hle membrane may then be a layer sprayed or glued
directly on the slabs~
Preferably according to the invention the tensible
strength of the surface layer is more than l kp/cm2, prevent-
ing the surface layer from being disentegrated by heavy
showers and nails.
The mineral wool for the facing and roofing preferably
has a specific weight above 50 kg/m3 and an air permeability
below 0.62 m2/h mm W.C. The air permeability specifies the
amount of air passing through a l m2 slab of mineral wool per
hour with a drop in pressure through the slab of l mm water
column per m. The mineral wool may be produced from fibres
collected on a perforated conveyer passing at the end of a
spinning chamber into which a thermosetting bonding agent is
atomized. The bonding agent may be a phenolic resin, for
example a phenolformaldehyde resin, or possibly a flexible
type of phenolic resin such as latex- or acryl-modified
phenolic resin, which latter are more resistant to impacts
from nails and other hard objects hitting the facing. The
layer of mineral wool is compressed simultaneously with
setting or curing of the bonding agent. The compression
must be sufficient to obtain a specific weight of the
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. ~ral wool in excess of 50kg/m3 and in most applications
preferably more than 100 kg/m3. It is possible to further in-
crease the compression and possibly to corrugate the slabs
in order to increase the strength sufficiently to be able to
increase the distance between the supports.
The mineral wool may be dyed in the manufacturing process
with a suitable dye or the facing may be painted after its
mounting. Further it is possible to use a raw material in the
manufacture producing dark or black fibres. The water repellant
properties of the mineral wool may be improved by a silicone
treatment in order to reduce the ~eat~l~rin~ra~,e,which dependent
on the climaticconditions is a few tenths of a millimetre
per year.
