GB2495993A - A floor for a building with built in drainage - Google Patents

Abstract

The floor 12 comprises a plurality of flooring panels 12a-h which may be carried on columns 16 positioned at intersections. The panels 12a-h are laid with gaps between them both longitudinally and laterally to allow to rain or other liquid to drain from the floor, and drains extend both longitudinally 50 and laterally 52 along and under each gap. The floor comprises an interconnection 55 which joins the longitudinal and lateral drains and may be coupled to downpipes 56 which may be located in the column. The panels 12a-h may be secured to longitudinal and lateral beams 22, 24 extending between and secured to the columns 16 and the beams may be engineered wood. The longitudinal drain may be precast concrete and the lateral drain may be synthetic rubber which forms a seal with the floor panels. The building may provide a multi-storey car park further comprising a ramp 14.

Description

Building This invention concerns buildings having a plurality of floors, particularly but not necessarily exclusively multi-storey car parks (also known as parking structures or parking garages) and mezzanine structures.

Multi-storey car parks and like structures commonly comprise a rectilinear framework carrying a plurality of substantially horizontal decking units put together to form individual floors, with ramps providing access from one floor to another. Commonly the framework is of steel and/or concrete and the decking units conventionally comprise concrete slabs precast or cast in situ. Care is needed to prevent water and materials such as oil, fuel and salts contained in it from penetrating joints between decking units (to cause * corrosion) and leaking through the joints (to damage vehicles parked on lower floors). To this end the joints are usually sealed and the deck assembly may be covered with a waterproof membrane. However such seats and membranes have a limited ability to cope with structural movements and thermal changes, and as a result cracks often appear in the vicinity of joints.

It is an object of the present invention to provide improved drainage in multi-storey car parks and the like.

Thus according to a first aspect of the invention there is provided a floor comprising a plurality of flooring panels each having first sides and second sides and being laid to form the floor with first sides separated by longitudinal gaps extending in a first direction and second sides separated by lateral gaps extending in a second direction, a plurality of longitudinal drains extending in said first direction along and under the longitudinal gaps, and interconnection means connecting the longitudinal drains to the lateral drains, whereby liquid is drained from the floor.

Said first and second sides may be mutually orthogonal.

Preferably each said gap is narrower than the drain under it.

The floor is preferably elevated upon columns carrying the interconnection means. Each interconnection means may comprise a drainage collar coupled to proximal ends of the drains, and each column may carry or be formed with a downpipe coupled to its respective drainage collar. The columns are preferably positioned at intersections of a rectangular grid.

The columns may carry a plurality of longitudinal beams and a plurality of lateral beams extending generally horizontally between the columns and supported thereby, with the flooring panels supported by and secured to said beams with said first sides of the flooring panels overlapping longitudinal beams and said second sides of the flooring panels overlapping lateral beams, * * At least some of said beams are preferably formed with a convex surface to which the flooring panels are secured, whereby said flooring panels are *.... 15 cambered to facilitate drainage of water towards sides thereof.

*:::: The flooring panels and the beams may be formed of wood, possibly engineered wood.

The longitudinal drains may be formed of a rigid material such as precast concrete and configured and arranged to resist a load upon the overlying flooring panels, and there may be seals between these drains and the overlying flooring panels. The lateral drains may be formed of a resilient material such as synthetic rubber and configured and arranged for sealing engagement with the overlying flooring panels.

In a second aspect the invention extends to a building including a floor as above. Such building may comprise a multi-storey car park having a plurality of said floors, with the drains configured and arranged to prevent liquid falling from one floor to a floor below. The multi-storey car park may comprise one or more ramps for cars to pass from one floor to another, with the or each ramp comprising a plurality of ramp panels laid with gaps between their sides and drains underlying said gaps.

According to a third aspect of the invention there is provided a modular construction system for constructing an elevated floor, which construction system comprises a plurality of columns configured and arranged to be positioned vertically and spaced apart longitudinally and laterally in a regular array, a plurality of mutually similar flooring panels beams configured and arranged to be secured to the columns and extend horizontally therebetween to form the floor with longitudinal and lateral gaps between adjacent sides of the flooring panels, and longitudinal and lateral drainage elements respectively configured and arranged to extend in use along and under the longitudinal and lateral gaps, characterised in that the drainage elements are so dimensioned and the flooring panels are so dimensioned relative to the spacing of the *.... 15 columns that the width d of the gaps is less than the width of the drainage elements.

Each flooring panel, which may be formed of wood, possibly engineered wood, is preferably so dimensioned as to provide an integral number of car parking bays of standard size. Each flooring panel may also includes utility services interconnectable between adjacent panels, eg "plug-and-play" electrical connections.

In a fourth aspect the invention provides a method of constructing an elevated floor comprising providing a plurality of vertical columns spaced apart longitudinally and laterally in a rectilinear array, securing to the columns a plurality of flooring panels with their sides spaced apart to form gaps, and securing under said gaps longitudinal and lateral drainage elements extending along and under the gaps to drain liquid from the floor.

Other aspects of the invention will be apparent from the following description, which is made by way of example only with reference to the accompanying schematic drawings in which -Figure 1 is an isometric view of a building illustrative of the invention constructed on a rectilinear grid and having an elevated floor and a ramp; Figures 2 to 4 show elevations of the building of Figure 1 respectively at grid line A, grid line 1 and grid line E; Figure 5 shows in plan view columns and longitudinal and lateral beams of the building of Figure 1; Figure 6 illustrates in plan view a connection between beams and a typical column at grid point C3; Figure 7 illustrates in plan view a connection between beams away from * a column; Figures 8 to 10 are sections of the building of Figure 1 respectively at *..: 15 grid line 5, grid line 3 and grid line 2 and particularly illustrating flooring panels *:::: of the building; Figure 11 illustrates part of a flooring panel in side elevation; Figure 12 is an isometric view illustrating the construction of a flooring panel; Figure 13 shows drainage of the building of Figure 1 in plan view; Figure 14 illustrates in plan view the drainage arrangement around a typical column at grid point C3 where drains interconnect; Figure 15 is an isometric view of the drainage arrangement at grid point C3; Figure 16 is an isometric view of the drainage arrangement where drains interconnect away from a column; Figure 17 is a vertical section illustrating a longitudinal beam, a drainage element and flooring panels; Figure 18 is a vertical section illustrating a lateral beam, a drainage element and flooring panels; and Figure 19 is a vertical section illustrating drainage across the ramp of the building of Figure 1.

Referring first to Figures 1 to 4 these show a building indicated generally at 10 constructed on a rectilinear grid indicated by longitudinal grid lines 1 to 6 and lateral grid lines A to E. As illustrated, the lateral grid lines ito 6 are spaced apart by 4000 mm and the longitudinal grid lines A to E are spaced apart by 2400 mm (which is the width of a standard parking bay) but will be understood that the spacing may be varied.

The building 10 has an elevated floor 12 accessed by a rat-np 14. The * * floor 12 comprises a plurality of rectangular flooring panels 12a to 12h -to be described in more detail hereinafter -carried on columns 16 positioned at selected intersections of the grid lines, ie in the illustrative building 10 at grid points Al, A3, A5, A6, Cl, C3, El and E3. The columns 16 are standard HI-section steel columns of the kind known as universal columns UC 254x254x73, although it will be understood that other columns may be used.

The ramp 14 comprises a plurality of ramp flooring panels 14a to 14d supported between shear walls 18 of engineered wood and is completed at its lower end by a concrete approach 15 formed in situ. The floor 12 is bounded by a crash barrier 20.

The floor 12 is secured to longitudinal beams 22 and lateral beams 24 extending between and secured to the columns 16. The beams 22 and 24 are formed of glued laminated timber, commonly known as glulam, although beams of different engineered wood or other materials may be used. In the illustrative building 10 the longitudinal beams 22 are 800x240 glulam GL32c beams and the lateral beams 24 are 600x200 glulam GL24c beams.

The building 10 is illustrative of the invention. In comparison with the arrangement shown in Figure 1 the building may be (a) extended both longitudinally and laterally in modular fashion to accommodate multiple parking bays on a floor 12 and (b) extended vertically -eg to form a multi-storey car park -by the addition of more floors, and additional access ramps arranged in a fashion that will be understood by those skilled in the art. Thus for use as a car park a building of the general form shown in Figure 1 may have lateral grid lines spaced apart by 16000 mm rather than the 8000 mm of the illustrative building 10. Similarly a building of the general form shown in Figure 1 but extended vertically as for use as a multi-storey car park may have columns of different size or configuration. The longitudinal and lateral beams of the building 10 may be differently dimensioned or of some material other than g!ulam (or even, in some arrangements, be omitted altogether, as will be *.... 15 explained later herein). And other features of the building 10 may also be varied. 4*** * . *

The arrangement of columns 16 and beams 22, 24 is shown more clearly in Figure 5, which also shows lateral beams 26 that support the flooring panels of the ramp 14 and are standard H-section S275JR steel beams.

The way in which the longitudinal beams 22 and the lateral beams 24 are secured to a central column 16 (ie a column at grid point C3, within the grid rather than at its edge) can be seen in Figure 6. A fitch plate 28 is secured in the proximal end of each beam 22, 24 by gluing and bolting in well-known fashion. Four orthogonally arranged fin plates 30, one corresponding to each fitch plate 28, are welded to the column 16. Then the flitch plates 28 are bolted to the corresponding fin plates 30. The beams 22,24 are centred with respect to the grid lines I to 6 and A to E. The fin plates 30 for the longitudinal beams 22 are centred with respect to the longitudinal grid lines 1 to 6 and the fin plates for the lateral beams 24 are offset. The beams 22, 24 are secured to columns 16 at the edge of the grid in similar fashion, but with only a three-way connection rather than a four-way connection.

The longitudinal beam 22 and lateral beams 24 also intersect away from the columns 16, ie in the illustrative building 10 at grid points A4, A2, C2 and E2. The way in which they are connected together at grid point C2 can be seen in Figure 7. The longitudinal beams 22 terminate at grid points such as C2 whereas the lateral beams 24 are continuous therethrough. At a grid point such as C2 a fitch plate 32 is secured in the proximal end of each longitudinal beam 22 by gluing and bolting in well-known fashion. Two welded steel tees 34 are bolted to the lateral beam 24 on the sides thereof which face the terminal ends of the longitudinal beams 22. Then the fitch plates 32 are bolted to the corresponding tees 34. The beams 22 and 24 are connected together at *.... is grid points on the edge of the grid in similar fashion, but with only a single tee (on the appropriate side) rather than two.

The floor 12 of the illustrative building 10 will now be described with reference to Figures 8 to 12.

The floor 12 is made up of a plurality of rectangular flooring panels 12a to 12h secured to the longitudinal and lateral beams 22, 24. In the illustrative building 10 most of these flooring panels are nominally 8000 mm long (ie in the longitudinal direction) and 2400 mm wide (ie in the lateral direction), corresponding to the dimensions of the grid, although the panels 12a and 12b at the top of the ramp 14 have a nominal length of only 4000 mm. It will be understood however that the invention is not limited to such dimensions; and for use as a car park, for instance, the flooring panels may be 16000 mm long or otherwise configured to fit a selected grid pattern.

The flooring panels 12a to 12h are all of similar construction, illustrated by Figures 11 and 12. Each comprises a frame 36 of 47x185 mm timber comprising a pair of side pieces 38 (which in use extend longitudinally) bridged by a plurality of transverse joists 40 secured at their ends to the side pieces 38.

A sheet 42 of 30 mm timber ply is secured to the upper face of the frame 36 to provide a deck. A sheet 44 of 15 mm fire board is secured to the under face of the frame 36 to provide a soffit.

The flooring panels 12a to 12h are not laid tightly side to side but rather are laid (and appropriately dimensioned) with gaps between them both longitudinally and laterally as will be described in more detail later herein, The ramp flooring panels 14a to 14d have a construction generally similar to that of the flooring panels 12a to 12h but with certain differences of detail that will also be described later herein.

As is well known, the floors of multi-storey car parks get wet, particular from rainfall and blown-in rain, and this water needs to be drained away to avoid damage to the structure and hazards such as ice formation. In addition, cars in the car park may drop fluids such as fuel and oil which is damaging to car bodywork, and such fluids also needs to be drained away along with the water, to avoid damage to cars parked on lower floors. Accordingly the illustrative building 10 is furnished with comprehensive drainage extending along and under the aforementioned gaps between the flooring panels. As shown in Figure 13 this drainage comprises both longitudinal drainage elements 50 and lateral drainage elements 52, and in addition lateral gutters 54 under the ramp 14 (Figure 1) which will be described separately.

As shown in Figure 14 longitudinal drainage elements 50 extend along tops of the longitudinal beams 22 and lateral drainage elements 52 extend along tops of the lateral beams 24, and at columns 16 they are coupled to a generally rectangular drainage collar 55 formed in two-parts from galvanised steel. (Other materials may be used).

The arrangement at grid point C3, and certain other details, can be seen in Figure 15. The drainage collar 55 extends around the column 16. (It is formed in two parts to avoid having to fit it by sliding it down the column 16).

On two opposed sides the drainage collar 55 is cut away to receive proximal ends of the two adjacent longitudinal drainage elements 50, which are formed of ethylene propylene diene monomer (EPDM) rubber. On its other two opposed sides the drainage collar 55 is cut away to receive proximal ends of the two adjacent lateral drainage elements 52, which are formed of precast concrete. On these two sides, and within the H-section of the column 16, the drainage collar 55 is coupled to two down pipes 56 (Figure 14) whereby water and other liquid is carried away. It will be understood that in a multi-storey * building a down pipe 56 may discharge into a drainage collar 55 below it. It will * is also be understood that the down pipe(s) may be replaced by other arrangements: for instance the column 16 itself may be formed to channel liquid downward.

EPDM rubber is a resilient material and its use to form the longitudinal drainage elements 50 serves two purposes as follows. First, when the flooring panels 12a etc are secured to the longitudinal beams 22 the longitudinal drainage elements 50 are compressed and thereby form seals, beneath the flooring panels, to prevent leakage of drained liquids. And second the EPDM drainage elements conform to the upper faces of the longitudinal beams 22, which are cambered to facilitate drainage. (The flooring panels 12a etc1 as 28 previously described, extending longitudinally and with lateral joists, similarly conform to the camber when secured to the longitudinal beams 22. Those skilled in the art will appreciate that the provision of a camber is advantageous in comparison with the conventional provision of a sloping floor, typically with a fall of 1 in 60, which creates constructional problems by creating different levels at different mounting points).

Precast concrete is a rigid material and thus the lateral drainage elements 52 resist deformation of the flooring panels 12a etc above them, so that cars are safely carried.

-The intersection between longitudinal and lateral drainage elements is illustrated by Figure 16. As shown therein the (rigid) lateral drainage element 52 includes a mid-section 52a recessed to receive the (resiliently deformable) longitudinal drainage element 50.

Figure 17 shows a cross section through a lateral beam 24, looking towards a column 16 at a central grid point C3. Timber bearers 60 extending along the length of the longitudinal beams 22 and parallel to their upper faces *..e..

* are secured to the beams 22 and screwed to joists 40 (see also Figure 11) of * 15 overlying adjacent flooring panels 12e and 12f, which are thereby supported by *** and secured to the longitudinal beams 22.

As can be seen from Figure 17, and to be understood from the foregoing description, the flooring panels 12e, 12f are separated by a gap 62, which extends laterally along the line of the beam 24. The width d of the gap 62 is 10 mm. The precast concrete drainage element 50 is carried by the lateral beam 24 and extends along and under the gap 62 to receive liquid draining through it. To this end the drainage element 50 is formed with a lengthways channel 50a and an upwardly extending neck portion bridging the gap 62 and engaged on each side thereof with the underside of the deck sheets 42 of the flooring panels 12c and 12e. By this means liquid draining through the gap 62 discharges into and is carried away by the channel 50a.

The drainage element 50 is little narrower than the nominal 200 mm width of the lateral beam 24 which carries it, and the channel 50a occupies a substantial part of its cross section.

Figure 17 also shows bolts 64 whereby the flitch plates 28 are secured within the ends of the longitudinal beams 22 (the uppermost of which bolts 64 are countersunk) and the bolts 66 whereby the fitch plates 28 are in turn secured to the fin plates3o, as described above with reference to Figure 6.

Figure 18 shows a cross section through a longitudinal beam 22 supporting two adjacent flooring panels 12h and 12f by means of timber bearers 60 screwed to the joists 40. The soffits 44 (see also Figure 12) terminate just short of the bearers 60 and (although not shown in Figure 18) there are bearing pads between the bearers 60 and the joists 40 to which they are screwed. * .

There is a gap 68 between the adjacent flooring panels 12h and 12f * and the EPDM lateral drainage element 52 carried by the longitudinal beam 22 **..

extends along and under this gap 68 to receive liquid draining through it. The a...

n drainage element 52 has a cross section comprising two walls compressed (by the screw connection between the bearers 60 and the joists 40) against the underside of the flooring deck sheets 42 to provide a watertight seal each side of the gap 68. The width d of the gap 68 is 10 mm and the walls of the drainage element 52 have a widthways separation greater than this, although the overall width of the drainage element 52 is somewhat less than the nominal 200 mm width of the longitudinal beam 22 that carries it. The drainage element 52 also comprises a lengthwise ridge between the walls which extends upwards within the gap 68 and divides the drainage element 52 into two channels.

Comparing Figures 17 and 18 (which are of similar scale) it can be seen that the cross sectional area of the channel 50a in the longitudinal drainage element 22 is substantially greater than the combined area of the two channels in the lateral drainage element 52. This gives the longitudinal drainage element substantially greater carrying capacity, to allow the lateral drainage element 52 to drain into it. Also, the longitudinal drainage element 50 is dimensioned and otherwise configured and arranged to avoid its becoming blocked by detritus in the draining liquid.

At the top and the bottom of the ramp 14 are laterally extending precast concrete drainage elements underlying gaps in the floor 12, like the lateral drainage &ements 52 but formed on one side (in a manner which will be readily understood by those skilled in the art) to accommodate the slope of the ramp 14. Between top and bottom of the ramp gaps between adjacent ramp flooring panels are underlaid by transverse gutters. This is illustrated by Figure 19. Adjacent ramp flooring panels 14a and 14b supported at their sides by a *...fl * laterally extending H-section steel beam 70 are laid so that their sides are S.....

* is separated by a gap 72. Rain or other liquid on the ramp 14 drains through the *.. . * gap 72 and is carried away by a transverse gutter 74.

Those skilled in the art will now appreciate that the present invention offers particular benefit in providing effective drainage both longitudinally and laterally and that the key to its effectiveness lies in the gaps between flooring panels1 which are left open to allow liquid on a floor to drain through and underlaid by coextensive drainage elements arranged to carry the liquid away.

As well as being effective this drainage arrangement saves time and cost, and eases construction management, because there is no need for specialists on site to apply seals to joints between flooring panels as is conventional. Further, ongoing maintenance costs are reduced because there are no seated joints requiring repair.

Also, inasmuch as a building embodying the invention may be constructed largely of wood, the invention offers the benefit of near carbon-neutral construction.

The invention may be used in the construction of multi-storey car parks, where carbon-neutrality may be of particular interest in offsetting carbon emissions from cars. However it will be understood that the invention is not limited to the construction of car parks. It may, for instance, be used to construct a mezzanine floor in, say, a supermarket, to deal with spills without unduly inconveniencing customers.

Other modifications and adaptations may be made without departing from the scope of the invention. For instance, whilst a modular arrangement as described herein is likely to be of most general use, the principle of two-way underfloor drainage could be applied to non-modular structures. Also, whereas the invention has been described and illustrated in relation to a structure with S.....

* rectangular modules, it might be applied to structures of other form such as a S.....

* 15 floor with triangular tesselations and hence three-way drainage. (In this regard, *.

for the avoidance of doubt, the terms longitudinal and lateral as used herein should not be deemed restricted either to drainage in only two directions nor to mutually orthogonal drainage elements). Further, whilst the illustrative building described herein has flooring panels carried on separate beams, it should be understood that the flooring panels themselves may be configured and arranged to be self-supporting between columns or the like. To provide electrical or other services through the building the floor panels may conveniently include lines, pipes etc with standard connectors at the sides of the panels for assembling a network that does not require special filling or commissioning, ie a network of the kind commonly known as plug-and-play".

The flooring panels may also be pre-marked to indicate parking bays, traffic directions and so forth.

Claims (1)

1. <claim-text>Claims 1. A floor comprising a plurality of flooring panels each having first sides and second sides and being laid to form the floor with first sides separated by longitudinal gaps extending in a first direction and second sides separated by lateral gaps extending in a second direction, a plurality of longitudinal drains extending in said first direction along and under the longitudinal gaps, and interconnection means connecting the longitudinal drains to the lateral drains, whereby liquid is drained from the floor.</claim-text> <claim-text>2. A floor as claimed in claim 1, characterised in that said first and second sides are mutually orthogonal. * *</claim-text> <claim-text>* 3. A floor as claimed in claim 1 or claim 2, characterised in that each * S said gap is narrower than the drain under it. -*Se * *. ** S</claim-text> <claim-text>4. A floor as claimed in any preceding claim characterised in that the floor is elevated upon columns carrying the interconnection means.</claim-text> <claim-text>5. A floor as claimed in claim 4, characterised in that each interconnection means comprises a drainage collar coupled to proximal ends of the drains.</claim-text> <claim-text>6. A floor as claimed in claim 5, characterised in that a said column carries or is formed with a downpipe coupled to its respective drainage collar.</claim-text> <claim-text>7. A floor as claimed in any of claims 4 to 6, characterised in that the columns are positioned at intersections of a rectangular grid.</claim-text> <claim-text>8. A floor as claimed in any of claims 4 to,7 characterised in that the columns carry a plurality of longitudinal beams and a plurality of lateral beams extending generally horizontally between the columns and supported thereby and the flooring panels are supported by and secured to said beams with said first sides of the flooring panels overlapping longitudinal beams and said second sides of the flooring panels overlapping lateral beams.</claim-text> <claim-text>9. A floor as claimed in claim 8, characterised in that at least some of said beams are formed with a convex surface to which the decking panels are secured, whereby said decking panels are cambered to facilitate drainage of water towards sides thereof.*..fl. * * *</claim-text> <claim-text>* * -*.* * 15 10. A floor as claimed in claim 8 or claim 9, characterised in that the flooring panels and the beams are formed of wood.</claim-text> <claim-text>11. A floor as claimed in claim 10, characterised in that the flooring panels and the beams are formed of engineered wood.</claim-text> <claim-text>12. A floor as claimed in any preceding claim characterised in that the longitudinal drains are formed of a rigid material and configured and arranged to resist a load upon the overlying flooring panels.</claim-text> <claim-text>13. A floor as claimed in claim 12, characterised in that the longitudinal drains are formed of precast concrete.</claim-text> <claim-text>14. A floor as claimed in claim 12 or claim 13, including seals between the longitudinal drains and the overlying flooring panels.</claim-text> <claim-text>15. A floor as claimed in any preceding claim characterised in that the lateral drains are formed of a resilient material and configured and arranged for sealing engagement with the overlying flooring panels.</claim-text> <claim-text>16. A floor as claimed in claim 15, characterised in that the lateral drains are formed of synthetic rubber. * . * 10</claim-text> <claim-text>*.**** * 17. A floor substantially as hereinbefore described with reference to *r": and as shown in the accompanying drawings.</claim-text> <claim-text>**.*** * . *:::: 18. A building comprising a floor as claimed in any preceding claim.</claim-text> <claim-text>19. A building as claimed in claim 18, characterised in that said building comprises a multi-storey car park having a plurality of said floors and the drains are configured and arranged to prevent liquid falling from one floor to a floor below.</claim-text> <claim-text>20. A building as claimed in claim 19, characterised in that said building comprises one or more ramps for cars to pass from one floor to another and the or each ramp comprises a plurality of ramp panels laid with gaps between their sides and drains underlying said gaps.</claim-text> <claim-text>21. A modular construction system for constructing an elevated floor, which construction system comprises a plurality of columns configured and arranged to be positioned vertically and spaced apart longitudinally and laterally in a regular array, a plurality of mutually similar flooring panels beams configured and arranged to be secured to the columns and extend horizontally therebetween to form the floor with longitudinal and lateral gaps between adjacent sides of the flooring panels, and longitudinal and lateral drainage elements respectively configured and arranged to extend in use along and under the longitudinal and lateral gaps, characterised in that the drainage elements are so dimensioned and the flooring panels are so dimensioned * relative to the spacing of the columns that the width d of the gaps is less than * ***** * : 10 the width of the drainage elements. * 4S444.4.* 22. A modular construction system as claimed in claim 21, *4**.* * 5 characterised in that each flooring panel is so dimensioned as to provide an integral number of car parking bays of standard size.23. A modular construction system as claimed in claim 21 or claim 22, characterised in that each flooring panel includes utility services interconnectable between adjacent panels.24. A modular construction system as claimed in any of claims 21 to 23, characterised in that the flooring panels are formed of wood.25. A modular construction system as claimed in claim 24, characterised in that the flooring panels are formed of engineered wood.26. A modular construction system substantially as hereinbefore described with reference to and as shown in the accompanying drawings.27. A method of constructing an elevated floor comprising providing a plurality of vertical columns spaced apart longitudinally and laterally in a rectilinear array, securing to the columns a plurality of flooring panels with their sides spaced apart to form gaps, and securing under said gaps longitudinal and lateral drainage elements extending along and under the gaps to drain liquid from the floor.* 28. A method of constructing an elevated floor substantially as * : 10 hereinbefore described with reference to and as shown in the accompanying flSee* * . drawings. ***.* * **..*** * * * * * ** 4</claim-text>