GB2156874A - Dry-laid floors - Google Patents

Abstract

The floor comprises relatively spaced and parallel concrete beams 1 to which are secured a plurality of composite load-supporting panels 6, the panels 6 bridging the gaps between said beams 1 and each such panel 6 having a plastics foam layer 7 (e.g. of polystyrene) and an upper chipboard or other wood-based layer 8. Wooden or other noggins 10 may be arranged beneath abutting edge regions of the panels 6 to support those edge regions at locations spaced between the neighbouring beams 1. Such edge regions may be shaped to define a gap between the lower layers 7 of otherwise edge-to-edge abutting panels 6 to receive a conduit 11 in which pipe and wire service ducts 9 extend, access to these ducts 9 being provided, at appropriate locations, by omitting areas of the upper layers 8 of the panels 6 and replacing these areas by removable hatch covers 12. An alternative way of supporting the ducts 9 from beneath by polystyrene blocks is described and illustrated. <IMAGE>

Description

SPECIFICATION Dry-laid floors This invention relates to dry-laid flooring. A number of alternatives to the traditional system of wooden joists having floorboards fastened to their upper surfaces have been employed during recent years, principally with a view to decreasing the amount of timber involved, speeding up installation and/or increasing the thermal insulation of the finished floor. Many of these alternatives indeed offer various advantages, as compared with the traditional joists and boards system, but they have their own individual drawbacks, some of which are not always immediately apparent.

An object of the present invention is to provide dry-laid flooring which avoids, or at least significantly reduces, the disadvantages exhibited by known dry-laid floors and their methods of installation.

According to the invention, there is provided a dry-laid floor ocmprising a plurality of relatively spaced and parallel or substantially parallel concrete beams defining substantially flat upper abutment surfaces to which upper surfaces are secured a plurality of composite load-supporting panels, the panels bridging the gaps between said concrete beams and each such panel exhibiting a lower synthetic plastics foam layer and an upper chipboard or other wood-based layer.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a somewhat diagrammatic plan view of a ground floor constructed in accordance with the invention showing the position of conduits and ducts for pipe and wire services, Figure 2 is a section, to an enlarged scale, taken on the line ll-ll in Fig. 1 and illustrates the arrangement of service ducts and an access panel thereto, Figure 3 is a section, to an enlarged scale, taken on the line Ill-Ill in Fig. 1, Figure 4 is a section, to an enlarged scale, taken on the line IV-IV in Fig. 1, Figure 5 is a section, to an enlarged scale, taken on the line V-V in Fig. 1, Figure 6 is an enlarged sectional elevation showing the construction and arrangement of infill pieces around the periphery of a floor constructed in accordance with the invention, Figure 7 is an enlarged and laterally exploded sectional view illustrating the junction between two composite load-supporting panels of the floor, and Figure 8 is a similar view to that of Fig. 2 but shows an alternative construction.

Referring to the accompanying drawings, the ground floor that is illustrated comprises a plurality of relatively spaced and parallel or substantially parallel concrete beams 1 of which, in the example being described, there are six, the longitudinal axes of these beams 1 being denoted by broken lines in Fig. 1 of the drawings and the cross-sectional shape of each such beam 1 being visible in Figs. 2, 4 and 5 of the drawings. The ground floor is surrounded by a conventional brick or other footing 2 (Fig. 1) and it will be seen that the opposite ends of the beams 1 are supported on this footing 2. In the simple example which is being described, the room is oblong but it could, of course, be of some other shape.In addition, only a single thickness of the footing 2 is illustrated but the footing 2 could be in the form of a cavity wall in which case the footing 2 shown in Fig. 1 of the drawings would be an "inner" footing which supports the opposite ends of the concrete beams 1, that inner footing being surrounded by an "outer" footing to complete the cavity wall.

In the simple example that is being described, the longitudinal centre lines of the parallel beams 1 are spaced apart from one another at intervals of substantially 600 mms.

Where (which is not illustrated in the drawings) an internal partition wall or the like is provided that extends parallel to the concrete beams 1, that partition wall or the like has two immediately laterally neighbouring beams 1 arranged supportingly beneath it, the space between upper portions of those two neighbouring beams 1 being filled, at the time of installation, by a known commercially available filling material.It will be seen from the drawings that each beam 1 is of symmetrical configuration with respect to a vertical plane which contains the longitudinal axis of that beam 1 and that it comprises an integrally connected lower flange 3 and upper head 4, said beams 1 being machine-made prestressed concrete beams that are known per Se. The head 4 of each beam 1 has a substantially flat and substantially horizontally disposed upper abutment surface 5 that may advantageously, but not essentialiy, be rippled/roughened to improve its keying co-operation with an adhesive as will be further described below.

In accordance with the invention, the drylaid flooring also comprises a plurality of composite load-supporting panels 6, the panels bridging the gaps between the concrete beams 1 and each such panel 6 exhibiting a lower synthetic plastics foam layer 7 and an upper wood-based layer 8 which is preferably.

but not essentially, chipboard. The panels 6 may advantageously be those known commercially as Thermafloor (Registered Trade Mark), the lower synthetic plastics foam layer 7 of such a panel 6 being a rigid, extruded polystyrene foam having a closed cell structure and the upper layer 8 being moisture-resistant flooring grade chipboard. These two layers 7 and 8 are adhesively secured to one another by a relatively thin layer of a waterproof, or at least moisture and vapour resistant, polyvinyl alcohol, mastic or latex adhesive. The lower polystyrene layers 7 of these commercially available panels 6 are formed from polystyrene known commercially as Styrofoam (Re'gisternd Trade Mark).This polystyrene material contains a fire-retarding additive so that each Thermafloor (Registered Trade Mark) panel 6 complies with the Class 1 fire rating of British Standard No. 476, Part 7, 1971.

Although the use of polystyrene for the layer 7 is greatly preferred, some other foamed synthetic plastics material having sufficient strength and durability could be employed as an alternative.

It should, perhaps, be explained at this point that Thermafloor (Registered Trade Mark) panels and other similar flooring panels have been extensively used when supported from beneath, throughout substantially their complete areas, by solid concrete, concrete blocks, polystyrene blocks or conventional floor boards but it has been found that they have sufficient strength to act alone as loadsupporting panels which bridge gaps between concrete beams and which therefore have major areas of their lower surfaces not directly supported from beneath.

The Styrofoam (Registered Trade Mark) lower layer 7 of each Thermafloor (Registered Trade Mark) panel 6 is such an effective vapour check that a separate vapour barrier is unnecessary except where the internal conditions are exceptionaily high in humidity and temperature and such conditions are very rare indeed in domestic situations in the United Kingdom.

Fig. 1 of the drawings shows, in heavy broken lines, the positions of pipe and wire service ducts 9 and Figs. 2, 4 and 5 illustrate the arrangement of those ducts 9 in flooring in accordance with the invention. As can be seen in Fig. 2 of the drawings, a plurality of timber noggins 10 are supported by the upper surfaces of the lower flanges 3 of the beams 1 and, where the service ducts 9 extend at locations which are spaced from the periphery of the floor as shown in Figs. 1 and 2 of the drawings, the lower synthetic plastics layers 7 of appropriate panels 6 do not abut against one another but are spaced apart so that the ducts 9, which are arranged in rectangular cross-section conduits 11, can lie between their neighbouring edges.The upper layers 8 of the same panels 6 are even further spaced apart so as to receive between their edges a longitudinally extending inspection hatch cover 1 2 that is secured in position by wood screws 1 3 extending downwardly through the layers 7 into the noggins 1 0. Further wood screws 1 4 extend downwardly through the neighbouring edges of the panels 6 into the same underlying noggins 1 0.

Figs. 4 and 5 of the drawings show similar arrangement except that, in these cases, the service ducts 9 concerned are at the periphery of the floor rather than well spaced from that periphery. The lower layer 7 of at least one appropriate panel 6 is foreshortened where no hatch cover is required (Fig. 4) and both the lower layer 7 and the upper layer 8 of at least one appropriate panel 6 are foreshortened where an inspection hatch cover 1 5 is to be provided (Fig. 5).In this latter case, the edge region of the appropriate panel 6 does not actually bear upon the upper abutment surface 5 of the head 4 of the beam 1 concerned and a wooden plank 1 6 of the same thickness as the layer 7 of each panel 6 and the same width as that of the head 4 of each beam 1 extends lellgthwise above the upper abutment surface 5 of the beam head 4 concerned and is glued to that abutment surface.Wood screws secure the overlapping edge of each panel layer 8 to the corresponding plank 1 6 and further wood screws secure the inspection hatch cover 1 5 to that plank 1 6. Filler blocks 1 7 that are preferably formed from expanded or extruded polystyrene fill the gap between the neighbouring beam 1 and the adjacent inner wall 2, each block 1 7 defining a ledge which is supported from beneath by the flange 3 of said beam 1 and a shelf which indirectly supports the ducts 9 by way of their enclosing conduits 11.A relatively narrow upper portion of each filler block 1 7 extends upwardly to the horizontal level of the top surfaces of the panel 6 so that its upper extremity is immediately beneath the internal plaster 1 8 of the wall 2 where that plaster 1 8 is faced by a skirting board 1 9.

Fig. 3 of the drawings illustrates a position where access may be obtained to the underfloor space beneath the panels 6. Timber plates are glued to the upper abutment surfaces 5 of the beam heads 4 and the edges of the flooring panels 6 are secured to the timber noggins 10 and to these timber plates by wood screws.

Figs. 6 and 7 of the drawings show the abutting edges of the panels 6 to a larger scale and in greater detail. It will be seen that one edge of each upper layer 8 is formed with a groove 20 and that the co-operating edge of the neighbouring layer 8 is formed with a tongue 21 whose shape matches that of the groove 20. The underlying edge surfaces of the layers 7 are substantially flat abutting surfaces and, during installation on site, a layer of adhesive 22 is applied between these abutting surfaces to secure and seal them to one another. A conventional sealant gun is advantageously used for this purpose but manual application by a brush from a pot or tin of adhesive is equally effective. The adhesive/sealant that is used may again conveniently, but not essentially, be a waterproof, or at least moisture and vapour resistant, latex or acrylic adhesive.With the tongued and grooved co-operation between the edges of the panel layers 8 and the adhesively sealed abutment between the underlying edge surfaces of the polystyrene or other foam layers 7, there is very little, if any, vapour penetration between the panel joints, such vapour penetration being so low as to be negligible except under internal conditions of exceptionally high temperature and humidity. Fig. 6 shows the provision of infill pieces 23 around the edges of a floor whose load bearing surface is afforded by the panels 6. The infill pieces 23 are of L-shaped cross section and are preferably formed from polystyrene foam which may again advantageously be that known by the Registered Trade Mark "Styrofoam". An expanding polyurethane foam, such as "FEB Handifoam" (Registered Trade Mark) may be used as an alternative.At the right edge, as seen in Fig. 6 of the drawings, the upright limb of the illustrated infill piece 23 lies alongside the tongues 21 of the upper panel layers 8 in marginally spaced relationship therewith whereas, at the left edge, again as seen in Fig. 6 of the drawings, the illustrated infill piece 23 is inverted and its relatively thick horizontal limb lies alongside the grooves 20 of the panel layers 8, again with a small degree of space therebetween. The surfaces of the infill panels 23 which lie close to the edges of the panel layers 7 are secured to those edges by a layer of adhesive 24 which adhesive 24 may conveniently, but not essentially, again be a waterproof, or least moisture and vapour resistant, latex or acrylic adhesive.

The same adhesive, it will be remembered, secures the panel layers 7 to the upper abutment surfaces 5 of the beam heads 4.

The width of the panels 6 matches the spacing between the concrete beams 1 so that, as a rule, the edges of immediately neighbouring panel 6 will abut one another centrally above the heads 4 of the beams 1.

Where a room of a shape which will not allow this arrangement to exist throughout the floor area is to be dealt with, edge support for the panels 6 is provided from beneath by using the minimum necessary number of timber noggins 10 as described above with particular reference to Figs. 2 and 3 of the drawings.

Fig. 8 illustrates an alternative construction to that which is illustrated in Fig. 2, the construction of Fig. 8 being particularly, but by no means exclusively, appropriate for use where conditions are relatively high in humidity and temperature. Instead of employing the noggins 10, expanded polystyrene blocks 25 are arranged with their upper surfaces abutting against the lower surfaces of the composite panels 6, opposite edge regions of the blocks 25 resting on the lower flanges 3 of neighbouring beams 1.The service ducts 9 extend immediately above, and are supported by, the blocks 25 and lie in gaps in the lower layers 7 of appropriate panels 6. Additionai protection against vapour penetration through these service ducts gaps is furnished by providing sheets 26 of polyethylene which sheets 26 have their opposite edges sandwiched between the tops of the blocks 25 and the bottoms of the panels 6, central regions of the sheets 26 that lie in said gaps extending over the tops of the service ducts 9 themselves.

The sheets 26 should, of course, be of sufficient thickness to avoid easy tearing whilst still being relatively flexible. Adhesive may, where required, be employed to keep their opposite edges in their appointed positions.

It has been found that, when flooring constructed in accordance with the invention using Styrofoam (Registered Trade Mark) IB grade is usad in the panels 6, that flooring has the required long term load-bearing capability. When subjected to a quite high compressive loading of 80kN/m2, no reduction in load-bearing capability is noticed after a very long period of time and no effective creep tends to occur. Even when the loading is raised to 250kN/m2, a compression of the layer 7 of only substantially 5 per cent occurs and this very high loading is well above, by a factor of at least three times, the loading which it is ever likely to receive under domestic housing circumstances. The thermal and sound insulation properties of flooring in accordance with the invention are both excellent and such flooring can be installed with exceptional speed and ease.

Claims (11)

1. A dry-laid floor comprising a plurality of relatively spaced and parallel or substantially parallel concrete beams defining substantially flat upper abutment surfaces to which upper surfaces are secured a plurality of composite load-supporting panels, the panels bridging the gaps between said concrete beams and each such panel exhibiting a lower synthetic plastics foam layer and an upper chipboard or other wood-based layer.

2. A floor as claimed in claim 1, wherein the lower synthetic plastics foam layer of each of said panels is a rigid, extruded polystyrene foam having a closed cell structure.

3. A floor as claimed in claim 1 or 2, wherein the upper layer of each of said panels is in the form of a moisture-resistant flooring grade chipboard.

4. A floor as claimed in any preceding claim, wherein each of said concrete beams is a machine-made pre-stressed beam having an integraliy connected lower flange and upper head, said head exhibiting, in use, a substantially horizontally disposed upper abutment surface.

5. A floor as claimed in claim 4, wherein the upper abutment surface of the head of each beam is rippled/roughened to improve its keying co-operation with an adhesive.

6. A floor as claimed in any preceding claim, wherein the longitudinal axes of said beams are, wherever possible, spaced apart from one another by distances of substantially 600 millimetres.

7. A floor as claimed in any preceding claim, wherein an at least partially surrounding brick or other footing is provided, the opposite ends of said beams being supported on that footing.

8. A floor as claimed in any preceding claim, wherein, where an internal partition wall or the like is provided that extends parallel to said concrete beams, that partition wall or the like has two of said concrete beams arranged supportingly beneath it in immediately laterally neighbouring relationship with one another.

9. A floor as claimed in any preceding claim, wherein pipe and wire service ducts are accommodated by forming gaps in the lower synthetic plastics foam layers of appropriate panels, the upper layers of those panels remaining unbroken except where inspection hatch covers are provided.

10. A floor as claimed in claim 9, wherein said ducts are supported from beneath by synthetic plastics blocks, and wherein additional protection against vapour penetration is provided by arranging flexible synthetic plastics sheets to extend over the ducts and have opposite edge regions thereof sandwiched between the tops of said synthetic plastics blocks and the bottoms of said panels.

11. A floor as claimed in any preceding claim, wherein abutting edge regions of the upper layers of said panels are matchingly tongued and grooved and a layer of the abutting edges of the panels.

1 2. A dry-laid floor substantially as hereinbefore described with reference to any of the constructions illustrated in the accompanying drawings.