Patent Publication Number: US-2010126100-A1

Title: Flooring Member

Description:
The present invention relates to a flooring member and particularly, but not exclusively, to a flooring member for use with underfloor heating. 
     BACKGROUND OF THE INVENTION 
     A problem of solid wood flooring and engineered wooden flooring comprising a plywood base structure with a hardwood surface veneer is that it is an insulator and does not efficiently transmit heat from an underfloor heating system to a room space above the flooring. Typically an underfloor heating system installed underneath a wooden floor has to operate at a temperature between 2 and 5 degrees above the desired operating temperature to account for the undesirable insulating properties of the wooden floor. 
     It is an object of the invention to provide a flooring member having a wooden upper surface, which conducts heat more efficiently than flooring of the type described above. 
     SUMMARY OF THE INVENTION 
     According to the present invention there is provided a flooring member comprising a metallic base layer, a metallic intermediary layer, a wooden upper layer, and a core made from spaced plywood members mounted between the metallic base layer and the metallic intermediary layer. 
     The metallic layers provide enhanced heat transfer properties and also provide an even heat across the surface of the wooden upper layer. 
     Preferably the spaces between adjacent members of the plywood core extend between the metallic base layer and the metallic intermediary layer. The spaces may be filled with metallic material or alternatively may include a web extending between the layers to improve heat transfer between the layers. 
     The plywood members preferably extend longitudinally of the flooring member and the spaces are preferably longitudinally disposed between adjacent plywood members. 
     Corresponding first and second connection means may be disposed on respective longitudinal edges of the flooring member for connecting a plurality of flooring members together. The first connection means may comprise a half-dovetail slot extending along one edge of the flooring member and the second connection means may comprise a half-dovetail projection extending along the other edge of the flooring member. 
     The connection means are advantageous because they tend to draw adjacent members together, in use. Furthermore the first and second connection means may be made from metallic material, which improves conductivity of heat between the layers. 
     Preferably the wooden upper layer is made from a hardwood of between 2 mm and 6 mm thickness and is bonded to the metallic intermediary layer. 
     The metallic base layer and metallic intermediary layer are preferably made from aluminium, but may be made from any suitable metal or metal alloy with good thermal conductivity. The first and second connection means are preferably made from similar material. 
     In a preferred arrangement, the metallic base layer, metallic intermediary layer and connection means are formed from a single sheet of aluminium. 
     The flooring member typically has a thickness of between 15 and 22 mm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: 
         FIG. 1  shows a schematic cross-sectional view through a flooring member of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT 
     Referring to  FIG. 1 , a flooring member is indicated generally at  10 . The flooring member  10  is a composite member and includes a metallic base layer  12 , a metallic intermediary layer  14 , a wooden upper layer  16  and a core  18  disposed between the base layer  12  and the intermediary layer  14 . The upper layer  16  is typically made from a hardwood such as oak, ash or maple, but may, if desired, be made from softwood. The upper layer  16  is between 2 mm and 6 mm thick and is bonded to the upper surface of the intermediary layer  14  with adhesive. Ideally the upper layer  16  is as thin as possible, in order to reduce the insulative effect of the wood as much as possible. However, the wood must be thick enough to maintain its structural integrity and to provide a hard wearing surface. The upper layer  16  also needs to be thick enough to allow for sanding of the surface, once the flooring member  10  has been fitted in a floor. 
     First and second connection means  20 ,  22  extend longitudinally along the respective sides of the flooring member  10 , to the left and right hand side of the flooring member respectively, as viewed. The connection means  20 ,  22  are made from the same material as the metallic base layer  12  and the intermediary layer  14 . This substantially box shaped structure can be extruded or formed, for example, from aluminium, which has excellent heat conducting properties. Alternatively it can be formed from other metals or composite metals, such as galvanised steel. The first connection means  20  is a half-dovetail slot. The slot  20  has a lower surface  24  extending in a plane substantially perpendicular to the edge of the flooring member and parallel with the base layer  12 , an upper surface  26  extending at an angle of approximately 15° relative to the base layer  12  upwards into the flooring member and a base surface  28  at the end of the slot extending substantially perpendicular to the base layer  12 . 
     The second connection means  22  is a half dovetail projection with a cross section adapted to be received and engaged by a half dovetail slot  20  of another flooring member. The projection similarly comprises a lower surface  29  extending in a plane substantially perpendicular to the edge of the flooring member and parallel with the base layer  12 , an upper surface  30  extending at an angle of approximately 15° relative to the base layer  12  upwards away from the edge of the flooring member and an end surface  32  extending substantially perpendicular to the base layer  12 . Optionally the length of the projection  22  may be marginally less than the depth of the slot  20  to ensure that the projection does not touch the base of the slot  28 , in use. 
     The core  18  is made from a plurality of spaced plywood members  34  extending longitudinally through the flooring member between the base layer  12  and the intermediary layer  14 . In the embodiment shown, there are five parallel sided plywood members  34 , adjacent members  34  being separated by space  36  of approximately 2 mm. In other arrangements, the plywood members  34  are narrower and the spaces  36  are larger. The plywood members  34  give strength to the flooring member, particularly when in compression and the purpose of the spaces is to allow for radiant heat to pass unimpeded between the plywood to the intermediary layer  14 . Optionally the spaces  36  can accommodate or be filled with a heat conducting material such as a metallic foil or web. Optionally, spacers may be provided to maintain the spaces between the plywood members. 
     In use, a plurality of flooring members  10  can be connected together to construct a floor or other timber faced surface. The half dovetail projections  22  engage in the half dovetail slots  20  of adjacent members  10  and hold them together. The angled upper part of the joint tends to draw adjacent members  10  together and the members snap together with little effort. No adhesive is required. The members  10  can be fastened down in conventional manner using a nail gun, screw fixings or adhesive. 
     When a plurality of flooring members  10  are assembled into a floor, the transfer of heat from an under-floor heating system through the floor is much greater than that for a conventional wooden or structurally engineered timber floor. The adjoining base layers  12  and adjoining intermediary layers  14  have the effect of evening out the heat distribution across the floor and heat is conducted from the base layer  12  to the intermediary layer  14  through the interconnected connection means  20 ,  22 . Furthermore, heat can radiate though the spaces  36  from the base layer to the intermediary layer. The addition of heat conducting material in the spaces  36  increases the rate of heat transfer. 
     The invention is beneficial because it enables under-floor heating systems to run at substantially lower temperatures than the prior art floors described for the same resultant surface temperature and heating effect. Furthermore, a system of flooring members  10  heats up more quickly than the prior art floors and the heat distribution is much more even, due to the effects of the base layer  12 , the intermediary layer  14  and the increased number of efficient heat transfer positions between the layers  14 ,  16 . The reduction in under-floor heating temperature is typically around 3° Celsius (C.), which is a significant reduction, given that typical operating temperatures are between 30 and 50° C. 
     Another advantage of the flooring members is that they are structurally strong due to their composite construction and are stable when subjected to under-floor heating.