e. :: . À:. À: Title: Sound Insulating Panel
Field of the Invention
The invention relates to a sound insulating panel for use in buildings, and particularly for use as a floor panel in concrete slab separating floors to provide acoustic insulation.
Background to the Invention
Floor panels are used in buildings, and in particular floor structures, as an alternative to traditional materials such as wooden floorboards. The panels can be made with a variety of different types of layers adhered to one another so as to obtain a flooring panel with particular characteristics, for example particular sound transmission characteristics.
In modern building practice, the permissible level of acoustic transfer between rooms in domestic dwellings has been reduced. In particular floor structures between vertically separated rooms need improved airborne sound transmission and impact sound resistance characteristics. This has necessitated additional material content for both floors and the associated ceilings underneath to provide the necessary sound insulation. However this increases the overall thickness of the total floor and ceiling construction, hence increasing costs.
It is an aim of the present invention to provide a panel which offers reduced acoustic transmission for concrete slab separating floors in buildings.
Summary of the Invention
In accordance with the present invention, there is provided a sound insulating panel for use in buildings, the panel comprising an upper loadbearing sheet, such as Shipboard, adhered a: e.
À. .:: À. e:e Àe ece to a fibrous sheet. The fibrous sheet is preferably a fibre mat made from polyester or other plastics material, or a rebond foam mat made from scrap foam shredded to crumb and crushed and glued together.
The thickness of the layers is preferably selected to produce a panel which when used with concrete slab separating floors fulfils the requirements of the Building Regulations Part 'E' concerning the passage of sound between buildings, and thus has a minimum of 17dB ALw when tested to BS EN ISO 140-6: 1998. This may be achieved by having a thickness for the upper load-bearing layer in the range 30-lOmm, and more preferably 25-15mm, and with a thickness of the fibrous sheet in the range 20-lmm, and more preferably 15-4mm.
With a panel formed from a sheet of chipboard of thickness 18mm and polyester fibre mat 6mm thick, values of approximately 21dB l\Lw are obtained.
The invention will now be described, by way of example, and with reference to the accompanying drawing in which: Figure 1 shows a schematic diagram of a panel in accordance with the present invention when used within a building.
Description
Figure 1 shows a sound insulating panel 10 in accordance with the present invention when used within a building structure as part of a floor assembly. The composite panel 10 consisting of two layers forms a floating floor supported on a concrete slab separating floor 12 between multi occupancy dwellings. The floating floor reduces the impact sound transmission through the concrete slab sufficiently to comply with the requirements of the Building Regulations Part 'E' with regard to the transmission of sound between dwellings.
The panel or board comprises two sheets 14, 16 of different materials which, in combination, provide a panel with a minimum of 17dB Low when tested in accordance :. :e À.e À:e..
with BS EN ISO 140-6: 1998. Other relevant British Standards which apply are BS EN ISO 140-1: 1997, BS EN ISO 140-2: 1991 and BS EN ISO 717-2: 1997.
To form the panel, the two layers 14, 16 are laminated together with an adhesive comprising a urea formaldehyde-based resin used with a gypsum filler and 10% water and cured with a chemical hardener in which the active ingredient is phosphoric acid.
Typically the layers are pressed under weight or in a press so as to complete the adhesion.
The uppermost layer 14 forming the walking surface consists of moisture resistant tongue and grooved flooring grade chipboard of 22mm or 18mm thickness. The chipboard 14 is adhered over its lower surface to layer 16 which is a resilient fibrous mat which attenuates impact sound transmission. The fibrous mat is either polyester fibre mat or rebond foam mat.
With a composite panel formed from adjoining sheets of chipboard of thickness 18mm, and 6mm thick 400gr/m2 100% polyester fibre mat known at Vitaluxan 400_, the panel has a density of 14.18 kg/m2 and has acoustic attenuation of 21dB ILw when tested to the relevant British Standard.
The thickness of the chipboard layer and polyester mat can be varied depending on the acoustic attenuation required, with typically the chipboard having a thickness in the range 15-22mm and the polyester mat having a thickness in the range 4-15mm.
For such a panel using 18mm chipboard and 5mm thick 160kg/m3 rebond foam mat supplied by Vitec (a division of Kay Metzeler Ltd), the density of the composite panel is 13.20kg/m2.
The rebond foam is less expensive than the polyester but still provides sufficient acoustic attenuation of 18dB ALw. Again the chipboard thickness can be varied as required, usually in the range 18-22mm, and the rebond foam can be varied from 4-15mm. c: :
À e À À The combination of the fibrous mat with the chipboard is important for reducing impact sound transmission throughout the concrete floor.
By using the combination of layers within the panel, the sound insulation impact sound resistance characteristics can be provided by the panel at reduced mass and thickness, and hence therefore reduced cost, over prior art solutions.
As will be appreciated by someone skilled in the art, variations in the thickness of the individual layers can be made as long as at least 17dB Low impact sound resistance is achieved for the panel in its entirety.