The present invention relates to a fire retardant wall/roofing element for fabrication of wall/roofing constructions, of the type specified in the preamble of the following independent claim 1.

There are known and used various types of fire retardant wall/ roofing elements that have been approved for different fire rating classes. These known fire retardant elements are for the most part supplied as complete elements with a front and a back side that are designed to constitute the first and second sides of a wall structure/roofing structure composed of such elements. Such elements cannot be altered or adapted to stricter or to less strict requirements for fire safety at the various places where the fire retardant elements are to be mounted.

Such an element is known from EP patent application no. 213.103, which shows a fire retardant element comprising two layers of fire retardant material facing one another with channels on the opposing surfaces of the layers, which channels are filled with a heat energy absorbent material, and the two facing layer surfaces with their channels are separated by an intermediate layer of in¬ sulating material, as shown in said application's figure 5.

The purpose of the present invention is to provide a fire retar¬ dant wall/roofing element of the type mentioned in the introduc¬ tory paragraphs above, where during its production the element may be adapted, by means of the selection of various materials and dimensions for the layers of materials, to the various re¬ quirements for fire classification, strength grading and acoustic muffling that pertain for the various places. It is thus also possible to obtain wall/roofing constructions that satisfy a higher fire classification than the individual elements by the combination of two of the same or different elements.

This is achieved according to the present invention by means of the features that are disclosed in the characterizing clause of the following independent claim 1, together with the succeeding dependent claims.

By fabricating the elements with width and length dimensions of maximum of 600 mm and 2500 mm, the elements can be handled man¬ ually, provided that sufficiently light materials are selected.

Due to their construction, the elements are also easy to cut, an can thus be adapted to the conditions at the assembly site when the remaining section of the wall construction is smaller than the width of the element. Of course, the same is also true when the elements are mounted in a plurality of lengths, and the tota height of the wall construction deviates from a multiple of the elements' lengths.

To obtain a narrower or shorter element which is still framed by a U-profile of perforated steel, a desired width or length may b cut away from the element, after which the two remaining outer parts of the element are brought together, and the U-profiles ar joined by welding. Fire retardant sealants should then be in¬ serted between the facing cut side edges of the element parts.

The invention will be described in more detail in the following, with reference to the embodiment examples shown in the drawings, and where

fig. la in perspective shows an element according to the invention, with flush side edges, and

fig. lb shows the same with staggered side edges,

fig. 2 shows a fragment of the element in perspective and parti cross section,

fig. 3 shows a section through a wall construction composed of two layers of wall elements for producing a structure that satisfies a higher fire rating class than the elements individually,

fig. 4 shows a cross section through fragments of two elements spaced apart with sealing agents interposed between, and

fig. 5 shows the same, 'but with the elements placed directly against one other,

fig. 6 and 7 show the same as fig. 4 and 5, but with staggered element edges.

As shown in fig. la and lb, the fire retardant wall/roofing ele¬ ment 1, hereinafter referred to as element 1, has a preferably rectangular form and dimensions suitable for the manual handling of the element, for example, 600 mm width and 2500 mm length. The thickness of the element 1 will vary with the thicknesses of the materials used for the layers, and optionally with the number of layers. Suitable thicknesses for elements meeting the re¬ quirements of fire rating classes A60 and H60, respectively, can be 39.5 mm and 61.5 mm. A structure composed of two layers of elements of said fire rating classes A60 and H60 would fulfill the requirements of fire rating class H120, and would have a thickness corresponding to the sum of the above mentioned indivi¬ dual elements plus the thickness of the interlying steel U- profile, which is 1 mm, which would then be a total of 102 mm.

The element in fig. la is shown with a U-profile 9 of perforated, stainless steel which frames the side edges of the element, and fig. lb shows the same, but where the U-profile 9 has a step 9a formed by the staggered positioning lb. The elements 1 may thus be placed tightly together with a staggered slot which to a large degree reduces possibilities for penetration by tongues of flame.

Element 1 is constructed as shown in fig. 2, from two identical layers 3,3' with a partition layer 4. The layers 3,3' consist of form pressed, incombustible mineral wool fiber panels having a

3 volume weight up to 1500 kg/m , and the facing surfaces of which have open channels 7,7 extending along one of the main directions of the element, preferably the longitudinal direction, mutually spaced at a distance similar to that shown in the drawing, or less than the width of the channels 7,7'. Within the channels 7,7' are placed units 8,8' of heat energy absorbent material which can be formed of, for example, pouches made of aluminum foil and filled with a special preparation in powdered or liquid form. As shown in fig. 2, the channels 7 of one of the layers 3 are displaced sideways relative to the channels 7' of the other layer 3', so that the units 8,8' of heat energy absorbent mater¬ ial at least abut one another or overlapping each other, seen in a direction perpendicular to the main surfaces of the element 1. One achieves by this means the absorption of heat by the units 8,8' of heat energy absorbent material over the entire surface of the element in case of fire.

The partition layer 4 is made up of an inorganic, temperature re¬ sistant, mechanically strong material capable of withstanding temperatures up to 1600 1/2 C, for example, a material called "Pyrodur"— reg. trade mark. On the outside of the layers 3,3', as shown in fig. 2, is arranged an outer layer 5,5' consisting of incombustible felt that increases in volume with rising tempera¬ ture. A suitable material is, for example, "I 10-A" — reg. trade mark — from the firm 3M. For an element 1 having less stringent requirements to meet, the one layer 5,5' optionally may be omitted. The above mentioned material layers 3,3', 4 and 5,5' which together form one surface, are framed by U-profiles 9 of perforated stainless steel having a thickness of 0.5 - 1.0 mm. These U-profiles serve to hold the layers of material together s as to form a finished element 1 as shown in fig. la.

The two layers 3,3' with optional outer layers 5,5' may be dis¬ placed relative to one another at least transversely to the lon¬ gitudinal direction of the element 1, but preferably in both the longitudinal and the transverse direction, so as to form a stag¬ gered offset positioning lb at each of the longitudinal sides la,1a and the short sides la',1a' of the element 1. In this case the U-profile 9 is provided with a step 9a formed to correspond to the existing staggered configuration lb.

As mentioned above, the elements 1 are thus joined together both sideways and lengthwise to form wall constructions and, of course, constructions, where the joints or the slots between the adjacent elements 1,1 are broken/angled so that the possibility for penetration by tongues of flame is prevented or at least substantially reduced.

For example, when an element 1 having only one outer layer 5,5' on the outside of the layers 3,3' corresponding to, for example, fire rating class A60, is joined together with an element 1 that has two outer layers 5,5' on the outside of the layers 3,3' and corresponds to fire rating class H60, there is obtained a resul¬ tant element structure with the surfaces of the elements adjacent one another, that meets the requirements for fire rating class H120.

In a wall structure constructed of two such element layers A, B, the elements of the one layer A must be shifted sideways rela¬ tive to the elements 1 of the other layer B in order to avoid through-going element joints 10, as shown in fig. 3.

Examples of construction of elements 1 that meet the requirements for fire rating classes A60 and class H60, respectively, are the following:

A60

Partition layer 4: 1.5 mm "Pyrodur" — reg. trade mark.

Layer 3,3': "Inolit" — reg. trade mark, 16.5 mm.

Depth of the channels 7,7' in layers 3,3': 8 mm, which channels are filled with units 8,8' of heat energy absorbent material. An outer layer 5,5' on the outside of one of the layers 3,3', and designated "I 10-A" — reg. trade mark: 5 mm. Total thickness: 39.5 mm.

H60

Partition layer 4: 1.5 mm. Layer 3,3': 25 mm each. Outer layers 5,5': 5 mm each. Total thickness: 61.5 mm.

H120 composed of:

A60 39.5 mm.

H60 61.5 mm.

Thickness of interlying steel profile part: 1 mm.

Total thickness: 102 mm.

In construction of, for example, a fire retardant wall structure with elements as shown in fig. la, there are provided preferably two strands 11 of a deformable, fireproof material, for example, CP 25 — reg. trade mark — a product from the firm 3M — betwee the adjacent side edges of the elements 1, whereupon the element 1,1' are pushed together, so that the strands 11 are deformed an fill the joint/slot between the elements 1,1. This filling out of the joint/slot 10 between two adjacent elements 1 can also be done as shown in fig. 4 and 5 by placement between the side edge of the elements 1,1 of a band list 12 of incombustible felt that increases in volume with rising temperature, for example I 10 " reg. trade mark — from the firm 3M, together with the placement of two parallel strands 11 between the band list 12 and each element 1,1, whereupon the elements 1,1 are pushed together so that the strands 11 are deformed. Bands lists 12 may in additio be placed on the outside of the joint/slot 10.

When the side edges of the elements 1 are provided with a stag¬ gered configuration lb, the insertion of the fireproof sealing materials may be simplified to the placement of strands 11 in the angles of the facing staggered steps lb as shown in fig. 6, after which the elements 1,1 are pushed together so that the strands 11 are deformed and fill the parts of the joints/slots 10 extending at a right angle to the elements' 1 main surface. Here, as shown in fig. 7, band lists 12 may also be placed on the outside of the slots/joints 10.

The U-profiles 9 that frame the side edges of the elements 1 are made preferably of 0.5-1 mm stainless steel having a perforation degree of about 50%.