GB2099472A - Floor comprising conduits - Google Patents

Abstract

The floor comprises corrugated structural panels 18 laid over top flanges 15 of subsidiary floor beams 11. Top flanges 15 are set at a predetermined depth D below top flanges 16 of a plurality of primary floor beams 10. Services conduits 38 are provided above concrete covering the panels 18 and are in and/or between flooring panel supports, namely secondary corrugated steel panels 31. Services feed-in to any or all of the panels 31 is achieved via transverse feed-passages between ends of the panels 31. <IMAGE>

Description

SPECIFICATION Flooring The invention relates to flooring.

Buildings of the so-called steel-frame type of structure have spaced parallel primary floor beams with an interconnecting subsidiary beam system, normally at least spaced parallel secondary beams orthogonal to the primary beams, if not also spaced parallel tertiary beams between the secondary beams. Structural flooring of cast concrete is usually associated with such floor beam arrangements, most often with corrugated interconnected panels directly overlying coplanar upper primary and at least secondary beam flanges to receive the concrete. Services, particularly electrical cables, are conventionally provided through channels of the panels, being fed to the channels through directly superposed header ducting at right angles thereto, and having service outlets as cell-like devices on upper webs of the corrugated panels.The channels so fed require underlying plates for isolation purposes, such plates being interposed between those channels and the top flanges of the beams on which the panels rest. The header ducting is conveniently provided with a cover at the same level as concrete that embeds the panels except at the ducting. Overall heights of the panels and ducting are each commonly 70 mm to 80 mm giving an overall floor thickness of about 140 mm to 160 mm additional to the depth of the primary beams. Some reduction of that additional thickness has been achieved by allowing top flanges of the primary beams to protrude above the subsidiary beams that support the panels to an extent not exceeding the depths of those panels and thus not obstructing the header ducting.

In general, such structural floor systems are expensive. Mating apertures are required in top webs of the panels and in bottoms of the ducting.

Service outlet cells also require mating apertures in their bottoms and in top webs of the panels, and are embedded in a substantial thickness of concrete making it virtually essential to provide a much larger number of such cells than will ever be used simultaneously. Moreover, headed sheer anchors are required over all of the beams embedded in concrete to counter any tendencies for beams to twist/rotate or concrete to lift. To save expense it has become commonplace to employ only spaced sets of panel corrugations to accommodate services, obviously at some cost in terms of convenience in use.

Nonetheless, such systems, with built-in electrical earthing to the floor beams for customary structural steel panels and steel ducting, are popular on account of their incorporation of services into the overall thicknesses of the floors themselves without prejudicing structural integrity thereof.

It is an object of this invention to provide an alternative flooring system that is capable of more economic implementation without other unacceptable penalties.

According to one aspect of this invention, corrugated structural panels are laid over top flanges of subsidiary floor beams that are set at a level below top flanges of primary floor beams that exceeds the overall depth of the panels, and services conduits are provided above concrete covering the said structural panels, advantageously in and/or between supports for flooring panels. Such supports are conveniently of secondary corrugated panel form and, in any event, are readily end-spaced to provide crossing channels for main feeds previously via the aforesaid ducting. Appropriate sizes of flooring panels and lengths of supports therefor to expose end portions of the latter allow ready and selective access to feed channels and service conduits over the entire floor area as and how desired.

It is particularly preferred herein that the subsidiary beams carrying the structural panels are set at depths below top flanges of the primary beams that correspond to the combined desired or prescribed thickness of those panels and their overlying concrete. Indeed, that relative positioning of primary and subsidiary beams, i.e. at least secondary beams (if not also tertiary beams), so that their top flanges are at levels spaced substantially in accordance with the intended or required structural floor thickness can be viewed as another aspect of this invention. The advantages gained thereby are numerous and will be described in more detail later.For now, however, we point first to the immediate and direct superposition of the floor supports on the top flanges of the primary beams for electrical earthing integrity, and to minimisation of effective floor thickness additional to the depths of the primary beams.

It will, however, be apparent that all applications of this invention are of great flexibility as to positioning of services; remove any requirement for plates underlying the service conduit-affording supports; and at least reduce the additional floor thickness, thereby increasing usable volume of the building, i.e. reducing structural wall height requirements for a given specification of storeys of a building.

These and other advantages are attained by abandoning altogether the conventional wisdom represented by the above-mentioned fixation with economy in integration of services into essential structural elements, an effect that must be most surprising, especially in resulting in more efficient space utilisation in spite of an overall floor depth (i.e. from structural panels to the flooring surface proper) that is actually increased.

Turning now to other advantages, though not attempting to be exhaustive, we point to the fact that the second mentioned aspect of the invention actually enables the primary beams to act not only as shuttering for concrete casting but also as a datum level for the cast concrete. Furthermore, sheer anchors are then required only for subsidiary beams; there is little or no tendency to lift for concrete anchored below top flanges of primary beams; and the primary beams themselves are stiffened against rotation. Moreover, the subsidiary beams, being lower on the primaries, must require significantly less fire-proof coating.

Additionally, some sound dampening appears inevitable by partial encasing of the primary beams in concrete; and further sound-deadening is most readily achieved by underlaying the floor supports with suitable material.

It will also be appreciated that service outlets to positions below the floor system, say to ceiling of the lower storey, and if not separately provided as is usual, are readily achieved via tubes set into the concrete; and that hangers for any suspended such ceiling will be shorter due to the subsidiary beams being lower.

Practical implementation of this invention will now be described specifically, by way of example, with reference to the accompanying drawing in which: Figure 1 is a fragmentary section through a preferred floor system; and Figure 2 is a fragmentary section at right angles of the same floor system.

In the drawing, no effort is made to show dimensions to scale, the emphasis being on clarity of illustration for the purposes of description. Also, the relative sizes of beams and requirements of structural panels, etc. will be well known to those of reasonable skill in the art.

As shown, primary floor beams 10 (only one shown) are of substantially greater depth than secondary beams 12 extending in spaced parallel relation between spaced parallel primary beams in a welded lattice system that may further include at least spaced parallel tertiary beams, such as indicated dashed at 13, between the secondary beams 12.

The secondary beams 11 (also any tertiary beams 13) are shown with their top flanges 1 5 a predetermined depth D below the top flanges 1 6 of the primary beams. The depth D corresponds to the full intended depth of a structural floor comprised of corrugated structural steel panels 1 8 directly superposed on the secondary beams 11, and concrete 1 9 cast thereon.

Corrugations of the structural panels 1 8 are shown running transversely to the secondary beams 1 and the downwardly open channels 21 thereof are where services are run in conventional systems with a closure plate sandwiched between secondary beam top webs 1 5 and the bottom webs 22 of the panels 18, or at least one contiguous set thereof. For this invention, that, of course, is rendered unnecessary.

The structural corrugated panels 1 8 will be secured as desired, say by bolts at 24, to the secondary beams 11 and will normally have both of edge formations 25, 26 capable of nesting for overlapped juncture, and other formations (not shown), perhaps profile features, that aid keying thereto of the concrete 1 9.

However, and as shown, the concrete 1 9 is cast to the level of the upper surfaces of the top flanges 1 6 of the primary beams 10 thereby vastly aiding construction. Thus, the upper parts of the primary beams 10 (within the depth D) actually serve as shuttering during concrete casting. Also, the upper surfaces of the top flanges 1 6 of the primary beams 10 serve to establish a datum plane for levelling the concrete 1 9. Moreover, those primary beam top flanges 1 6 can further serve in locating and cooperating with concrete compacting vibrator apparatus. Sheer anchors are then required only in relation to secondary (or tertiary) beams as indicated at 28, and there is a much reduced tendency for concrete to lift or for any rotation of the primary beams 10.The latter, in fact, are effectively stiffened by their partial encasement in concrete, and rendered less liable to transmit vibrations and thus noise.

Laid immediately upon the concrete 1 9 are floor supports shown in the advantageous form of secondary corrugated steel panels 31 that will also preferably nest at least at edge formations 32, 33 that may coincide with top flanges 1 6 of the primary beams 10 and be secured thereto by bolting at 34.

Suitable flooring 36 is then laid upon the supports 31, usually as flat panels, and conveniently of chipboard or other desired material. The flooring supports afford services conduits, shown at 38 as being in downwardly open corrugations of the secondary corrugated panels 31, i.e. between bottom webs 39 of the panels 31 that engage the concrete 1 9 and/or primary panel top flanges 1 6. Outlets are readily afforded and/or affixed to the top webs 41 of the panels 31 by simply drilling and/or cutting out of the flooring 36 and the top webs 41 as desired.

Services feed-in to any or all of the downwardly open channels of the panels 31 is achieved by a particularly simple expedient of leaving gaps G between ends of those panels, thereby forming transversely extending feed-passages that are a distinct and obvious improvement upon the conventional ducting previously emplaced upon the structural panels 1 8. Manifestly, the feed passages in the gap G will be of the same height as the service conduits themselves, and actually coincide therewith.

So long as it is ensured that end portions 42 of the panels 31 are not covered by flooring 36, simple covers 43 may be emplaced with any (or no) desired jointing at junctures with the flooring 36. The panels 43 may thus be of the same material as the flooring 36, say chipboard, faced (44) if desired by steel protection plating, shown within its thickness but equally applicable exteriorly.

Should it ever be desired, tubes (46) can be emplaced through the bottom webs 22 of the structural panels 1 8 and the concrete 1 9 to take services through to the underside of the overall floor, say to service a suspended ceiling for which but short hangers would be required from bottom flanges 47 of the secondary beams 11.

Securement of subsidiary beams and structural panels 11 below the top flanges 16 of the primary beams 10 also ensures a smaller surface area of beams exposed and subject to fire resistant coating as required or desired.

Whilst the secondary beams 11 may rarely be of so much less depth than the primary beams 10 as appears in the drawing, there will virtually always be some differential that allows for a substantial reduction of the thickness hitherto added to the primary beams by a structural floor, even if abutment of the primary and secondary beam bottom flanges does not permit full accommodation of that overall floor depth below the primary beam top flanges as is preferred and shown.

In practice, flooring support panels such as 31 can be of any depth to suit requirements for services conduits, but will normally be substantially less deep than the structural panels 18, and substantially simpler and less expensive than hitherto used ducting over such panels 18. It will be appreciated that the flooring support panels could, if desired, run transversely of the direction shown.

As an example demonstrating added depth savings over conventional practice, we point to a typical overall depth of 70 mm to 80 mm for the structural panels 1 8 and a similar depth of concrete 1 9 above the upper webs of those panels 18. By contrast, a typical overall depth of flooring support panels is likely to be 60 mm to 70 mm, but with a flooring thickness of the order of 20 mm.

Claims (12)

1. A flooring system comprising a plurality of corrugated structural panels adapted to be laid over top flanges of a plurality of subsidiary floor beams that are set at a level below top flanges of a plurality of primary floor beams that exceeds the overall depth of the panels, a plurality of services conduits being provided above concrete covering the said structural panels.

2. A flooring system as claimed in claim 1, wherein the plurality of services conduits are provided in and/or between a plurality of supports for flooring panels.

3. A flooring system as claimed in claim 2, wherein said plurality of supports are of secondary corrugated panel form and are end-spaced to provide crossing channels for main feeds.

4. A flooring system as claimed in claim 1, wherein the plurality of subsidiary floor beams are set at depths below top flanges of the plurality of primary floor beams that correspond to the combined desired or prescribed thickness of those panels and their overlying concrete.

5. A flooring system as claimed in claim 1 or 4, wherein the plurality of primary and subsidiary floor beams are relatively positioned so that their top flanges are at levels spaced substantially in accordance with the intended or required structural floor thickness.

6. A flooring system as claimed in claim 5, wherein the level of the upper surfaces of the top flanges of the plurality of primary floor beams act not only as shuttering for concrete casting but also serve to establish a datum plane for levelling the cast concrete.

7. A flooring system as claimed in claim 5 or 6, wherein sheet anchors are required only for the plurality of subsidiary floor beams.

8. A flooring system as claimed in claim 6, wherein the plurality of primary floor beams are stiffened against rotation and partially encased in concrete to provide sound dampening.

9. A flooring system as claimed in claim 1, 2 or 3, wherein the plurality of flooring panel supports are underlaid with suitable sound-deadening material.

10. A flooring system as claimed in claim 2 or 3, wherein services feed-in to any or all of the plurality of flooring panel supports is achieved via transversely extending feed passages extending between ends of the plurality of flooring panel supports.

11. A flooring system as claimed in any one of the preceding claims, wherein service outlets to positions below the flooring system are achieved via tubes set into the concrete, said service outlets serving a suspended ceiling or the like for which a plurality of short hanges are required from bottom flanges of the plurality of subsidiary floor beams.

12. A flooring system substantially as herein described with reference to and as illustrated in the accompanying drawings.