CA1100733A

CA1100733A - Exterior facing for roofs, walls et cetera of buildings

Info

Publication number: CA1100733A
Application number: CA312,505A
Authority: CA
Inventors: HELGE HõYER
Original assignee: Rockwool International AS
Current assignee: Rockwool AS
Priority date: 1977-10-04
Filing date: 1978-10-02
Publication date: 1981-05-12
Also published as: AT360726B; IT7869285A0; IE781978L; DK140155B; GB2005746B; IE47571B1; GB2005746A; FI783008A; FR2405340A1; ATA711478A; FI62169B; NL7810005A; PT68613A; SE7810349L; DK437977A; FI62169C; NO783349L; ES473905A1; DE2842830A1; BE870997A

Abstract

ABSTRACT OF THE DISCLOSURE

An exterior facing for roofs, walls and the like of buildings to be mounted in form of overlapping or butt jointed elements or slabs on a non-watertight, inclining underlayer which facing consists of mineral wool contain-ing a bonding agent and having the fibres oriented sub-stantially parallel with the exterior surface.

Description

7~3 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 .

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 11(:)0733 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-' ' . :: ' .
. .
:

11~)(~733 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 ~`~
. ~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.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An exterior-facing for roofs, walls and the like of buildings to be mounted in form of overlapping or butt jointed elements or slabs on a non-water tight underlayer with an inclination in order to drain off the precipitation, said facing being formed of mineral wool containing a bonding agent and having the fibres oriented substantially parallel with the out-side surface at least in a layer adjacent to said outside surface.

2. A facing according to claim 1 in which said layer adjacent to said outside surface has a tensile strength of at least 1 kp/cm2.

3. A facing according to claim 2 in which the mineral wool has an air permeability less than 0.62 m2/h mm W.C.

4. A facing according to claim 1, 2 or 3 in which the mineral wool has a specific weight in excess of 50 kg/m3.

5. A facing according to claim 1, 2 or 3 in which the bonding agent is a hardened phenolic resin for phenoformalde-hyde resin.

6. A facing according to claim 1, 2 or 3 in which the bonding agent is a hardener.

7. A facing according to claim 1, 2 or 3 in which the bonding agent is a latex- or acryl- modified phenolic resin.

8. A facing according to claim 1, 2 or 3 in which the mineral wool contains a dye.

9. A facing according to claim 1, 2 or 3 in which the mineral wool at least in said layer adjacent the outside surface contains a silicone.