Ventilated facade insulation
US 2899821 A
Description (OCR text may contain errors)
Aug- 18, 1959 s. H. NYCANDER VENTILATED FACADE INSULATION Filed July 8, 1955 5 H. /Vycanaer 73 'W7 1r/y.
United States Patent() VENTILATED FACADE INSULATION Sven Hilding Nycander, Bromma, Sweden, assignor to Internationella Siporex AB, Stockholm, Sweden, a corporation of Sweden Application July 8, 1955, Serial No. 520,887
Claims priority, application Sweden July 15, 1954 1 Claim. (Cl. 72-18) In the erection of buildings, particularly concrete buildings, it is customary to improve the heat insulating properties of the external walls of the building by mounting light-weight concrete slabs on the outside of said walls. These light-weight concrete facing slabs may either be secured to the walls by mortar or other cement when the concrete in the wall is already set or they may be inserted in the molds for forming an external lling layer therein during the casting of the concrete forming the external wall so that they are firmly secured to the concrete.
The facades or external walls insulated in this manner are then usually coated with a layer of plaster so that the light-weight concrete slabs are entirely enclosed. In certain cases the outside of the plaster layer is in turn covered with glass mosaic tiles which are secured in the plaster.
Both when the light-weight concrete slabs are secured to the concrete walls either by the adhesion of the concrete mass in the mold or by means of mortar spread on the walls and when the outer layer of plaster is applied the light-weight concrete slabs absorb moisture which causes a reduction of their heat insulating capacity and at the same time is ydetrimental to the adherence of the plaster to the surface of the slabs. If the external layer of plaster is suiciently porous, it is true that the insulating layer may dry out slowly under favorable conditions, but if the plaster layer is dense and practically impermeable or when an external covering of glass mosaic tiles is used, the moisture is compelled to remain in the light-weight concrete slabs.
The present invention has for its main object to eliminate this disadvantage and to provide a ventilated facade insulation of the above-mentioned type in a simple manner. The invention thus relates to a facade insulation comprising light-weight concrete slabs mounted on the external walls of a building and the main feature of this facade insulation according to the invention is that the light-weight concrete slabs included in the facade insulation are provided with grooves in their `abutting edges so that a network of intercommunicating Ventilating channels is obtained in the insulation, said ventilating channels openly communicating with the outer air at the upper and lower edges of the facade insulation.
Generally, the light-weight concrete slabs are placed on the wall in such a way that said Ventilating channels run in the horizontal and vertical directions, but it is also possible to arrange the light-weight concrete slabs otherwise with the Ventilating channels forming angles other than 90, for example, 45, with the horizontal and the vertical plane, respectively.
The invention further relates to a light-weight concrete "ice g 2 slab for obtaining a ventilated facade insulation' of the type just dened and the main feature of the said lightweight concrete slab is that it is` provided with longitudinal grooves in at least two of its meeting edges and preferably in all four of its edges.
The invention now will be more particularly described with reference to the accompanying drawing showing somewhat dagrammatically and by way of example an external wall of a building having an outside insulation according to the invention.
In the drawing- Fig. 1 shows front elevation of a part of a facade insulated with light-weight concrete slabs and before the application of the plaster coating and Fig. 2 shows a partial vertical section through such a facade-insulated external wall in ready-coated condition.
In both gures, 1 is a concrete external wall of a building on the outside of which a plurality of heat-insulating light-weight concrete slabs 2 are rmly secured and covered externally by a layer of plaster 3 and if desired by glass mosaic tiles 4 (Fig. 2). The light-weight concrete slabs 2 are provided with longitudinal grooves 5 in all their four edges, the said grooves forming Ventilating channels 6 entirely enclosed by the light-weight concrete material in the joints between the slabs 2. The ventilating channels 6 form a network with both horizontal and vertical intercommunicating channel sections and the channel networn communicates with the outer air both at the upper and lower edges of the facade insulation as indicated by the arrows 7, as at the upper and lower edges of window apertures and the like. It is, of course, necessary to prevent water and impurities from penetrating into the channels, which can be effected at the upper edge of the facade insulation by allowing the roof 8, a window-sill or the like to project slightly in the usual manner to hide the upper openings of the channels in the insulation.
A corresponding ventilation may be obtained when each light-weight concrete slab is only provided with grooves along two meeting edges forming an angle to one another, provided that the light-weight concrete slabs are placed uniformly so that the grooves in the different slabs form the `same network wherein they all communicate with each other. It has been found desirable to locate the grooves closer to the insides of the light-weight concrete slabs than to their outsides in the finished insulation since 'then the air current through the Ventilating ychannels will be stronger thanks to the increased temperature of the complete wall nearer the interior of the building. Under all circumstances, however, care must be taken that the grooves do not open on the insides of the slabs, otherwise the channels will be choked up when casting the walls or when setting the slabs with mortar on a completed wall unless special precautionary measures are taken.
What I claim is:
A novel Wall construction of a building, the combination which includes an inner sustaining wall, a layer of insulating slabs adhesively bonded to the exterior face of said sustaining wall, one entire face of each insulating slab being bonded to a portion of the external surface of said sustaining wall by adhesive mortar, a substantially moisture-impermeable continuous coating adhering to the exterior side of said layer of insulating slabs, said insulating slabs being arranged in adjacent edge-to-edge relationship, each of said insulating slabs having a continuous 3 channel connecting together -the four remaining sides of said insulating slab, saidchannel being isolated -from the aforementioned front and back faces of said insulating slabs, said channels in adjacent slabs thus forming a concealed network of unobstructed intercommunicating 5 Ventilating channels extending throughout said layer of insulating slabs, and said network of unobstructed intercommunicating Ventilating channels opening into the outer air at the upper and lower margins of said insulating layer.
738,643 Van Camp Sept. 8, 1903 1,058,949 Diebel Apr. 15, 1913 1,644,996 Grossinger Oct. 1l, 1927 FOREIGN PATENTS 838,949 Germany May 15, 1952