Patent Application
20230265661
The present invention relates to the field of building structures.
Traditionally, thatched roofs are fire protected covering the laths of the roof structure with a fire-resistant and very diffusion permeable glass matting. Fire tests have shown that this method is functioning very well, and that it reduces burn-through on the face sections of the thatched roof. When a fire occurs in a thatched roof, only smouldering fire will occur on the face sections as the fire does not ignite any straw material. The fire will seek to the edges of the thatched roof, where there is more oxygen available. The presence of a surplus of oxygen increases the temperature in this region to above the melting temperature of the glass matting that melts at 600- 800° C., resulting in the fire getting free access to the underlying roof structure.
In order to avoid melting of the edge area of the glass matting, a narrow mineral wool mat of maximum 15 cm, preferably about 5 cm is used to cover the side edges and eaves of the thatched roof, thereby protecting the glass matting from melting. However, the presence of a mineral wool mat reduces the ventilation of the thatched roof in this area, causing areas with risk of rotting of the straw material. Furthermore, in the process of positioning the mineral wool mat, a considerable amount of dust is generated, and manipulation of the mineral wool mat results in breakage of the fibres, which, in turn, results in the formation of tiny fragments that no longer have the properties of a fibre. These tiny fragments can form small dust particles that cause irritation of the skin, eyes, nose and throat of the installer. In some cases, inhalation of the dust particles can lead to serious medical consequences.
The objective of the present invention is to provide a solution that solves at least some of the above problems.
Surprisingly, the inventors have found that mineral wool can be replaced by a very thin mineral fibrous sheet material for fire protecting building structures. This solution obliviates the problems with mineral wool and makes space for a much better ventilation of the building structures, such as the roof, floors, or facades. The mineral fibrous sheet material should be able to pass the flame retardancy test according to ISO 4589-3:2017, such that the mineral fibrous sheet material reaches an ignition temperature of 400° C. or higher in the test.
A first aspect relates to a building structure comprising a mineral fibrous sheet material (first type) having a Temperature Index measured according to ISO 4589-3:2017 of 400° C. or higher, wherein said sheet material has a thickness of at most 1 mm, and wherein mineral fibers forming said sheet material is coated with a coating adapted for retarding fire.
In the present context, the term “building structure” means a structural element forming part of a building, such as a roof, a floor, a façade, a wall or the like. Hence, it is not to be understood as a part of an electrical system.
In one or more embodiments, the mineral fibrous sheet material has a Temperature Index measured according to ISO 4589-3:2017 of at least 400° C., such as within the range of 400-2000° C., preferably at least 500° C., such as within the range of 500-1900° C., more preferably at least 600° C., such as within the range of 600-1800° C., such as at least 700° C., such as within the range of 700-1700° C., and even more preferably at least 800° C., such as within the range of 800-1600° C. A suitable example of such a sheet material is the XFR50 sheets produced by Scapa Group that is measured to have a Temperature Index measured according to ISO 4589-3:2017 above 1100° C., and probably above 1600° C.
As used herein, the term “mineral fiber” includes fibers manufactured from rock, slag, glass, or ceramic with or without binders. The mineral fibrous sheet material may be woven or non-woven (e.g., felt) and may e.g., be of glass fiber, silicate fiber, ceramic fiber and mixtures thereof.
In one or more embodiments, the sheet material has a mass per unit area of 100-1,500 gram per square meter measured according to ISO 2286-2:2016, such as 110-1,000 gram per square meter, preferably 120-500 gram per square meter measured according to ISO 2286-2:2016, and more preferably 130-400 gram per square meter measured according to ISO 2286-2:2016.
The mineral fibers are coated with a coating adapted for retarding fire. Examples of such a coating may e.g., be water glass, or a silicone, such as polydimethylsiloxane (PDMS) polymer, polydiphenylsiloxane (PDPS) polymer, or a polydimethyldiphenylsiloxane (PDMDPS) polymer. Preferably, the coating is a non-tacky silicone. Preferably, the coating comprises a nonorganic fire-resistant filler. Nonorganic fire-resistant fillers may be ceramic powder, metal, glass, metal oxides, or combinations of ceramic powder, metal, glass, or metal oxide fillers. Examples of fire-resistant fillers contemplated by the present invention are ferro oxide, titanium oxide, boron nitride, zirconium oxide, sodium silicate, and magnesium silicate, although others are suitable as well. Such coatings may e.g., be prepared as shown in US7652090, hereby incorporated by reference.
The sheet material has a thickness of at most 1 mm, preferably within the range of 0.1-1 mm, and more preferably within the range of 0.1-0.5 mm, e.g., 0.2-0.4 mm.
In one or more embodiments, the sheet material has a Limiting Oxygen Index measured according to ISO 4589-3:2017 of 30% or higher, such as at least 40%, preferably at least 50%, such as within the range of 60-100%, and more preferably at least 70%, such as at least 80%, and more preferably at least 90%. A suitable example of such a sheet material is the XFR50 sheets produced by Scapa Group that has a Limiting Oxygen Index measured according to ISO 4589-3:2017 of above 90%. Limiting oxygen index (LOI) is the minimum concentration of oxygen in a mixture of oxygen and nitrogen that is needed to support the flaming combustion of a material. It is expressed in volume percent (vol%). Standardized tests, such as the ISO 4589 and ASTM D2863, may be used to determine LOI values.
Preferably, the building structure is selected from the roof, floors, and facades.
In one or more embodiments, the building structure is a thatched roof structure, and wherein the mineral fibrous sheet material is forming part of the roof underlay. Preferably, the sheet material forms part of the underlay only at the side edges, eaves, and ridge of said thatched roof structure. The remaining part of the underlay may be a second type of mineral fibrous sheet material, e.g., having a melting point of 800° C. or higher, preferably a woven fiber glass sheet material with a chopped fiberglass sheet attached to its surface. Preferably, the second type of mineral fibrous sheet material is vapor permeable to allow for proper ventilation of the backside of the thatched roof. The term “vapor permeable” shall be described herein as meaning that gases and substances, which are carried or suspended in a gas (such as, but not limited to water vapor), can move across the sheet material.
Both the mineral fibrous sheet material (first type) and the second type of mineral fibrous sheet material may preferably be placed on the laths and/or rafters of the roof structure and below the roof. Alternatively, the mineral fibrous sheet material (first type) may be placed on top of the second type of mineral fibrous sheet material being placed on the laths of the roof structure and below the roof.
In one or more embodiments, the building structure is a façade with a cavity, preferably ventilated, between the building wall and the facade cladding, and wherein said sheet material is lining said building wall within said cavity.
When the façade comprises window and/or door openings, these openings are also lined with the mineral fibrous sheet material (first type). This way of fire protecting the window and/or door openings secures that if a window or door catches fire, the development of the fire will be substantially retarded.
In one or more embodiments, the façade is a part of a multifloored building, and wherein said cavity is blocked between two neighboring floors by an object covered by said sheet material (first type). Such an object may e.g., be of metal or wood, preferably metal.
In one or more embodiments, the façade is thatched. This type of façade has until now not been possible to make due to the risk of fire.
A second aspect relates to a method for establishing a fireproof building structure comprising covering or lining a building structure with a mineral fibrous sheet material (first type) having a Temperature Index measured according to ISO 4589-3:2017 of 400° C. or higher, wherein said sheet material has a thickness of at most 1 mm, and wherein mineral fibers forming said sheet material is coated with a coating adapted for retarding fire.
A third aspect relates to a method for establishing a roof construction for a thatched roof comprising:
A fourth aspect relates to a method for establishing a roof construction for a thatched roof comprising:
A fifth aspect relates to a method for establishing a façade for a building comprising:
As used in the specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about”, it will be understood that the particular value forms another embodiment.
It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.
The invention is described in more detail in the following detailed description of a preferred embodiment, with reference to the figures.
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| Number | Date | Country | Kind |
|---|---|---|---|
| PA 2020 00930 | Aug 2020 | DK | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/068677 | 7/6/2021 | WO |
