AU2020254705A1 - Step module for stairs - Google Patents

Abstract

Disclosed is an adjustable step module for stairs. The adjustable step module can comprise a first elongate tread member having first and second spaced-apart edges and a surface extending between the first and second edges. The adjustable step module can have one of the first and second edges configured to form a distal edge of the first tread member in use. The first tread member is able to be spaced below a second elongate tread member in the stairs in use. A first elongate riser member can have first and second spaced-apart edges and a surface extending between the first and second edges. The riser member can be configured to be arranged substantially perpendicular to the first tread member, and such that the riser member can be arranged between the first and second tread members in use. A tread member distance is defined as the distance between the in-use substantially perpendicular riser member and the distal edge of the first tread member. The module can be configured such that the tread member distance is adjustable. A riser member distance is defined as the distance between the first and second tread members. The module can be configured such that the riser member distance is also adjustable. In a variation, a tread member is configured for mounting between first and second riser members. A width of the tread member from one side edge to an opposing side edge is able to be selected prior to mounting the tread member between the first and second riser members. The step module can further be arranged in a modular pod.

Description

STEP MODULE FOR STAIRS

TECHNICAL FIELD

This disclosure relates to a step module for stairs used in the construction of stairways, typically for multi-floor buildings. The step module can be adjustable and can reduce the cost of and simplify the construction of stairs by permitting adjustment of both riser height and tread width.

BACKGROUND ART

Buildings such as multi- floor buildings can have varying floor to floor heights and therefore require different sized stairways to connect each level. Traditionally, stairways are designed to fit between levels in a building by dividing the floor to floor height by allowable dimensions for stairs determined by the relevant industry building standard. The stairway treads (horizontal portions) and risers (vertical portions) therefore can vary considerably depending on the particular building design. Thus, typically each stairway installation is custom built which can tend to be relatively expensive and time-consuming.

Modular and adjustable step units capable of joining together and forming a stairway have been developed to simplify and reduce the cost of stairway construction. For example, US 5,014,475A discloses an adjustable stair module in which a standardized module can be attached to other standardized modules. The vertical space between adjacent modules can be adjusted according to a specific installation. However, in US 5,014,475A, the horizontal space between adjacent modules is not even considered.

It is to be understood that, if any prior art is referred to herein, such reference does not constitute an admission that the prior art forms a part of the common general knowledge in the art, in Australia or any other country. SUMMARY

Disclosed herein is an adjustable step module for stairs. The adjustable step module in its simplest form can comprise a first tread member and a first riser member (e.g. for just a single step). The adjustable step module may be supplied as a kit (e.g. in a flatpack) for assembling the stairs on site. As explained in further detail below, the adjustable step module can be supplied with multiple tread members, multiple riser members, stringers, affixing mechanisms, assembly instructions, etc. The multiple tread members, riser members, stringers, etc. may be alike. The step module may also be adjusted (e.g. adapted) during assembly, such as to take into account the particular conditions (e.g. measurements, dimensions, etc.) of the site. As explained in further detail below, the step module may also be assembled in a manner whereby the one or more tread members, and one or more riser members, may each be independently mounted to the stringers, such that the tread members and riser members need not be affixed to each other.

The first tread member can be elongate and can have first and second spaced-apart edges. A surface can extend between the first and second edges. One of the first and second edges can be configured to form a distal edge of the first tread member in use. When in use in stairs, the first tread member may be spaced below a second (e.g. like) tread member.

The first riser member can be elongate and can have first and second spaced-apart edges. A surface can extend between the first and second edges. The riser member can be configured to be arranged substantially perpendicular to the first tread member (e.g. when in use). When in use in stairs, the riser member may be arranged between the first and second tread members. For example, the riser member may extend between the first and second tread members. As explained below, the riser member does not necessarily need to extend fully between the first and second tread members. A tread member distance can be defined as the distance between the in-use substantially perpendicular riser member and the distal edge of the first tread member. The module can be configured such that the tread member distance is adjustable.

A riser member distance can be defined as the distance between the first and second tread members. The module can also be configured such that the riser member distance is also adjustable.

Thus, the adjustable step module as disclosed herein is differentiated over e.g. US 5,014,475A in that each of the tread member distance and the riser member distance is adjustable. This dual adjustability imparts a considerable degree of in- use flexibility to the adjustable step module, enabling the module to be adjusted to a broad range of site conditions, as will be described in further detail hereafter.

In a first variation of the adjustable step module, the tread member distance may be adjusted by moving the riser member along the first tread member to one of a plurality of locations intermediate the first and second tread member edges.

For example, in this first variation, the riser member may comprise a plate which can be arranged to extend substantially perpendicularly to the first tread member in use. Further, the riser member may comprise a flange that can be arranged to project from an in use lower edge of the plate. The riser member can be positioned on the first tread member such that its flange can project away from the distal edge in use. The flange may be configured to function as a base of the riser member that is able to be moved along the first tread member to one of the plurality of locations intermediate the first and second tread member edges. Once in a desired position, the flange may optionally be affixed (e.g. by one or more fasteners, adhesive, spot-welds, etc.) to the first tread member. Thus, the riser member can stand upright. However, it should be understood that such affixing is not essential or necessary. In a second variation of the adjustable step module, the tread member distance may be adjusted by changing the distance between the first and second tread member edges. For example, the first tread member may be cut-to-size, or may be supplied in a predetermined range of widths, etc.

In this second variation, the tread member distance may be adjusted by providing (e.g. by supplying) a tread member insert. The tread member insert may be configured for mounting between the first and second riser members (e.g. it may be inserted into position once the first and second riser members have first been secured in the stairs). The first edge-to-second edge width of the tread member insert may be selected prior to mounting the tread member insert between the first and second riser members. As above, the tread member insert may be cut-to-size, or it may be supplied in a predetermined range of widths, etc.

In this second variation, the first riser member may comprise an in-use upper recess. The second riser member may comprise an in-use lower recess. The recesses may be arranged to receive thereat/therein a respective edge of the tread member insert to thereby mount the tread member insert between the first and second riser members.

In this second variation, the lower recess may be configured whereby the respective edge of the tread member insert can be inserted and retained therein (e.g. it may be affixed therein using adhesive, one or more fasteners, spot-welds, etc.).

In this second variation, the upper recess may be configured as a step or ledge, whereby the respective edge of the tread member insert can be positioned (e.g. dropped) thereon. Again, the edge of the tread member insert may be affixed on the step or ledge (e.g. using adhesive, one or more fasteners, spot-welds, etc.).

In this second variation, the upper recess of the first riser member may be integrally formed with a remainder of the first riser member. Thus, in use, the recess may extend along an in-use upper edge of the first riser member. Alternatively, the upper recess of the first riser member may be separately formed (i.e. it may be supplied as a separate component) to a remainder of the first riser member. In this alternative form, the recess may in use be arranged in relation to (e.g. to be spaced with respect to) an in-use upper edge of a remainder of the first riser member (e.g. when the stairs are formed).

In this second variation, the lower recess of the second riser member may be integrally formed with a remainder of the second riser member. The lower recess may in use extend along an in-use lower edge of the second riser member. Again, the respective edge of the tread member insert can be inserted and retained in the lower edge recess (e.g. it may be affixed therein using adhesive, one or more fasteners, spot-welds, etc.).

In this second variation, each riser member can comprise in-use upper and lower recesses. Thus, each riser member may be alike. Each such recess can be arranged to receive therein a respective edge of the tread member insert. However, it should be noted that, in a set of stairs, the initial riser member and the final riser member may each be supplied (or may each be adjusted on site) to have one of the recesses removed therefrom (i.e. the initial riser member can have its lower recess removed, and the final riser member can have its upper recess removed). This is because these recesses may not be required. Hence, special initial and final riser members may be provided (e.g. supplied with the kit/flatpack).

In this second variation, the tread member insert may comprise an optionally pre fabricated fibre-cement sheet. However, the tread member insert could instead comprise a timber sheet, a composite (e.g. fibre-polymer) material, a metal plate, etc. Advantages of e.g. a fibre-cement sheet include it being readily available, lightweight and strong, and readily able to be cut and shaped on site. For example, the fibre-cement sheet may be cut to a selected width prior to mounting it as the tread member insert between the first and second riser members. In both the first and second variations, the one or more tread and riser members, and the stringers, etc. can be fabricated from a sheet metal material (e.g. by press or roll- forming to provide for economies of production and scale). The sheet metal may be of (e.g. galvanised) steel or aluminium.

In further embodiments, the riser member distance may be adjusted by moving the second tread member with respect to the first riser member to one of a plurality of locations. Adjustment of the riser member distance can occur with each of the first and second variations as outlined above.

For example, the riser member distance may be adjusted in use by moving the second tread member up or down (e.g. generally vertically) with respect to the first riser member and the first tread member. This movement can, for example, take place during assembly of the stairs.

In an embodiment, a distal edge of the second tread member may be provided with a flange which, in-use, projects downwardly. Thus, when the second tread member is moved with respect to the first riser member (e.g. up or down), the distal flange can move with respect to the first riser member (e.g. up or down).

In one form, the distal flange can be moved (e.g. down) so as to overlap (e.g. in a horizontal plane) with the riser member. The distal flange may, when overlapping, abut or closely face an in-use external face (of a plate/body) of the riser member.

In another form, the distal flange can be moved (e.g. up) so as to be spaced from the riser member (e.g. spaced above the horizontal plane, and not overlapping). The distal flange may, when spaced from the riser member, still be in general alignment with the plate/body of the riser member.

In yet a further variation, the first (or each) riser member may be provided in a “split” format. In this regard, the first (or each) riser member may comprise an in- use upper component that is separately formed to a remainder of the first riser member. It should be understood that, depending on how the adjustable step module is viewed, the upper component may be considered to form a part of the first (or each) tread member (i.e. the upper component can be seen as a utility- or auxiliary-type component). In either case, when the second tread member is moved with respect to the riser member, the upper component can also move (e.g. be caused to move) with respect to the remainder of the first (or each) riser member (e.g. the movement can be up or down in use).

In this further variation, the first (or each) riser member upper component may be provided with a flange which, in-use, projects downwardly. Thus, when the second tread member is moved with respect to the first riser member, the flange of the upper component can also move (e.g. be caused to move) with respect to the remainder of the first (or each) riser member (e.g. the movement can be up or down in use). Again, the flange can optionally overlap with the remainder of the riser member.

Typically, with the adjustable step module as disclosed herein, the module comprises (e.g. it can be supplied with) a plurality of riser members and a plurality of tread members. As set forth above, the module can further comprise (e.g. be supplied with) opposing (i.e. typically two, alike) stringers. When the stairs are assembled, the stringers can be spaced-apart and can oppose each other.

The number of riser and tread members supplied can be pre-ordered or predetermined (e.g. at a factory). Alternatively, a suitable number of riser and tread members can be selected on site from those supplied in the kit/flatpack. The length of the stringers may also be pre-determined (e.g. pre-ordered).

Alternatively, the stringers may be cut to length on site.

During assembly, one or more of the riser members and/or one or more of the tread members may each be respectively mounted at respective end edges to the opposing stringers of the module. For example, the plurality of riser and tread members may each be independently mounted at their respective end edges to the opposing stringers of the module. The mounting can employ various fixing methodologies (e.g. screwing, bolting, welding such as spot welding, riveting, adhesives, etc.). Thus, one or more of the riser members and tread members may each be arranged in the module so as not to require affixing to each other.

However, various of the riser members and tread members can also be affixed to each other, using such various fixing methodologies.

Typically, the stringers (and/or also the plurality of riser and tread members) can be configured (e.g. the stringers and/or members may each be pre-configured) for this mounting. For example, the stringers can be supplied, in kit or assembled form, with (e.g. pre-attached) mountings to which each of the plurality of riser members and tread members can be readily affixed (e.g. using suitable fastener(s), adhesive, spot-welds, etc.). Optionally, the stringers can be supplied with a number of different mounting points/locations, to provide for full stair

adjustability. The ends of each of the plurality of riser members and tread members may also be configured (e.g. with suitable flanges, projections, tabs, etc.) to facilitate such mounting to the stringers.

Disclosed herein in another aspect is a step module for stairs. In its simplest form, the step module of the other aspect comprises an elongate tread member, and first and second elongate riser members. In use, the second riser member is arranged in the stairs above the first riser member. In the step module of the other aspect, the tread member can be configured for mounting between the first and second riser members. A width of the tread member (i.e. from one side edge to an opposing side edge) can be selected prior to mounting the tread member between the first and second riser members. For example, the tread member width can be predetermined prior to fabrication of the tread member, or the width can be determined on site (e.g. by cutting the tread member to size on site). Thus, the step module of the other aspect can provide for stair adjustability through the use of an on-site width-adjustable tread member. In the step module of the other aspect, the first riser member can have spaced- apart in-use upper and lower edges and a surface extending between the upper and lower edges. The first riser member upper edge can be configured to support thereat said one side edge of the tread member.

In the step module of the other aspect, the second riser member can have spaced- apart in-use upper and lower edges and a surface extending between the upper and lower edges. The lower edge can be configured to support thereat said opposing side edge of the tread member.

As above, in the step module of the other aspect, the tread member can be an optionally pre-fabricated fibre-cement sheet. However, the tread member can instead comprise timber, composite (e.g. fibre-polymer) material, metal, etc. Advantages of such a sheet include it being readily available, lightweight, strong, and easily able to be cut and shaped on site. For example, when the tread member is of fibre-cement sheet, it may be cut to a selected width prior to mounting it between the first and second riser members. This can impart considerable flexibility to construction of the stairs.

In the step module of the other aspect, the first, second and further riser members, and the stringers, etc. may each be fabricated from a sheet metal, which may e.g. be press- or roll- formed to provide for economies of production and scale. The sheet metal may be of (e.g. galvanised) steel or aluminium.

In the step module of the other aspect, the upper edge of the first riser member may be configured as a step or ledge (e.g. as an elongate step or ledge extending along the riser member upper edge). The step or ledge can support thereon said one side edge of the tread member. For example, the tread member can e.g. be dropped into place on the step or ledge. As above, the tread member can e.g. be affixed onto the step or ledge.

In the step module of the other aspect, the lower edge of the second riser member may be configured as a recess that extends along the lower edge (e.g. as an elongate recess extending along the riser member lower edge). The recess can be arranged to receive and support therein said opposing side edge of the tread member. For example, the tread member can e.g. be inserted into place in the recess. As above, the tread member can e.g. be affixed within the recess.

Typically, the step module of the other aspect comprises (e.g. it is typically supplied in kit/flatpack form) with a plurality of tread members and a plurality of corresponding riser members, with each tread/riser member pair being configured to support therebetween a respective tread member. The step module (kit/flatpack) can further comprise opposing stringers. When the stairs are assembled, each of the riser members can be mounted at respective end edges to the opposing stringers (e.g. using the methodologies as set forth above).

Typically, each of the riser members comprises a preconfigured upper edge to support said one side edge of a respective tread member thereat, and a

preconfigured lower edge to support said opposing side edge of a respective tread member thereat.

In a variation to the step module of the other aspect, and in place of the plurality of tread members, the step module can comprise (e.g. it can be supplied with) a cover plate. The cover plate can take the form of a tray. The cover plate can (be supplied to) correspond to the stringers. The cover plate may be arranged in use to form an underside beneath the plurality of riser members.

Thus, when the step module of the other aspect is assembled with the opposing stringers (e.g. with each of the riser members being mounted at respective end edges to the opposing stringers), the cover plate can be arranged in use to extend between (and be affixed along its edges to) the opposing stringers so as to form an enclosed underside of the riser members. When the cover plate is arranged (and affixed) in this way, a fill material (e.g. a cementitious material such as concrete), can be arranged in (e.g. poured into) a space that is defined between the plurality of riser members and the cover plate. Thus, the cover plate can allow the step module of the other aspect to function as a formwork for the (e.g. concrete) stairs to be formed. For example, the fill material once poured can be formed (e.g. screeded) into respective treads of the step module. In this way, the fill material can replace the tread members of the step module of the other aspect.

Additionally, the step module as disclosed herein (i.e. either of the aspects as set forth above) can be provided or can work together with an in-use upper landing and/or lower landing. The upper landing can be arranged at an in-use upper end of the stairs. The lower landing can be arranged at an in-use lower end of the stairs. Each landing may be configured whereby a fill material, such as concrete, can be arranged at the landing. For example, where concrete is poured to form the stairs (e.g. with the cover plate as set forth above), it can also simultaneously be poured into one or both of the upper and lower landings.

Each landing may comprise a tray. Each tray may have one or more side walls that extend up from and surround a base of the tray. Each tray may comprise one or more bracing members that extend from the one or more side walls between one side of the tray and an opposing side of the tray. The bracing members can strengthen and stiffen the tray.

As set forth above, typically, each tray is configured to receive therein the fill material (such as concrete) when the fill material is arranged to form the respective treads of the step module, i.e. a continuous flow of concrete can be poured between the trays of respective in-use upper and lower landings and in-use treads of the step module.

In a variation, the in-use upper and lower landings can receive fill material in the respective trays, separately from and independently of the treads of the step module, i.e. concrete can be poured into the trays of respective in-use upper and lower landings and cured before concrete is poured into the in-use treads of the step module. Or the step modules may not include poured concrete in their construction. Disclosed herein in another aspect is a step module for stairs. The step module for stairs is arranged in a modular pod. The modular pod is suitable for use as permanent formwork to be used to form a stairwell, etc. in a building. The modular pod can comprise the upper landing and the lower landing as set forth above. In use, the lower landing can be located at an intermediate location in the modular pod. In the pod, one such step module may extend down from the upper landing to the lower (intermediate) landing. Another such step module may extend down from the lower (intermediate) landing. As set forth above, each landing may be configured to receive therein a fill material, such as concrete, being the same fill material used to form the respective stairwell, etc. in a building. The fill material may be poured simultaneously into the pod formwork, each landing, and e.g. into the step module to form the treads thereof, i.e. a continuous flow of concrete can be poured. Thus, disclosed herein, in a further aspect, is yet another step module for stairs. The step module of the further aspect can comprise an elongate cover plate (e.g. as set forth above). Again, the cover plate may take the form of a tray. As set forth above, the cover plate can enable the replacement of the tread members in the step module when constructing the stairs. The step module of the further aspect can also comprise a plurality of in-use spaced apart elongate riser members. The riser members may be as defined as set forth in the aspects above. The riser members may be affixed to opposing stringers as set forth in the aspects above.

The cover plate can be arranged in use to form an underside beneath the plurality of riser members. As set forth above, this arrangement can allow for a fill material (e.g. concrete) to be arranged in (e.g. poured into) a space that is defined between the plurality of riser members and the cover plate. When so arranged, the fill material can be formed into respective treads for the stairs of the step module (e.g. the fill material can screeded into a tread shape). Thus, the step module of the further aspect can provide a formwork for stairs to then be formed by e.g. a cementitious material.

In an embodiment, the step module of the further aspect may further comprise opposing (e.g. two, like) stringers. Each of the riser members may be mounted at respective end edges to the opposing stringers. Further, the cover plate may be arranged in use to extend between the opposing stringers so as to form an enclosed underside of the riser members. Such an enclosed underside can better retain the fill material (e.g. when poured into the space). The step module of the further embodiment can also comprise the in-use upper landing and/or lower landing as set forth above.

BRIEF DESCRIPTION OF THE DRAWINGS

A number of embodiments of the step module will now be described, by way of example only, with reference to the accompanying drawings in which:

Figs, la, lb & lc are perspective views of stairs used in the construction of stairways, typically for multi- floor buildings;

Fig. 2a is a side view of a first embodiment of a step module wherein components of riser members and tread members have been adjusted into one of a plurality of locations relative to each other.

Fig. 2b is a side view of the step module of Fig. 2a where components of riser members and tread members have been adjusted into a second location of a plurality of locations relative to each other.

Fig. 2c is a perspective view of the step module of Fig. 2b. Fig. 3a is a side view of a second embodiment of a step module where

components of riser members and tread members have been adjusted into one of a plurality of locations relative to each other.

Fig. 3b is a side view of the step module of Fig. 3a where components of riser members and tread members have been adjusted into a second location of a plurality of locations relative to each other.

Fig. 3c is a perspective view of the step module of Fig. 3b.

Fig. 4a is a side view of a third embodiment of a step module where components of riser members and tread members have been adjusted into one of a plurality of locations relative to each other.

Fig. 4b is a side view of the step module of Fig. 4a where components of riser members and tread members have been adjusted into a second location of a plurality of locations relative to each other.

Fig. 4c is a perspective view of the step module of Fig. 4b.

Fig. 5a is a side view of a fourth embodiment of a step module where components of the tread members are inserts and are sized prior to mounting between riser members. In Fig. 5a, the tread members have been sized to a smaller size than the tread members of Fig. 5b.

Fig. 5b is a side view of the fourth embodiment of the step module, similar to Fig. 5a, but where the tread members have been sized to a larger size in comparison to the tread members of Fig. 5a.

Fig. 5c is a perspective view of the step module of Fig. 5a.

Fig. 6a is a side view of a fifth embodiment of a step module where components of the tread members are inserts and are sized prior to mounting between riser members. In Fig. 6a, the tread members have been sized to a smaller size than the tread members of Fig. 6b. In addition, the riser members are positioned in one of a plurality of locations.

Fig. 6b is a side view of the fifth embodiment of the step module, similar to Fig. 6a, but where the tread members have been sized to a larger size in comparison to the tread members of Fig. 6a. In addition, the riser members are positioned in a second of a plurality of locations.

Fig. 6c is a perspective view of the step module of Fig. 6b.

Fig. 7a is a side view of a sixth embodiment of a step module where components of the tread members are inserts and are sized prior to mounting between riser members. In Fig. 7a, the tread members have been sized to a smaller size than the tread members of Fig. 7b. In addition, the riser members are positioned in one of a plurality of locations.

Fig. 7b is a side view of the sixth embodiment of the step module, similar to Fig. 7a, but where the tread members have been sized to a larger size in comparison to the tread members of Fig. 7a. In addition, the riser members are positioned in a second of a plurality of locations.

Fig. 7c is a perspective view of the step module of Fig. 7b.

Fig. 8 is a perspective view an embodiment of stairs, Fig. 8 showing an enclosure that has been formed in the stairs which may contain a fill-material (e.g. concrete).

Fig. 9 is a perspective view of stairs comprising a step module when in use in a modular pod, the modular pod able to be used to form a stairway and stairwell in e.g. a multi-floor building.

DETAILED DESCRIPTION

In the following detailed description, reference is made to accompanying drawings which form a part of the detailed description. The illustrative embodiments described in the detailed description, depicted in the drawings and defined in the claims, are not intended to be limiting. Other embodiments may be utilised and other changes may be made without departing from the spirit or scope of the subject matter presented. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings can be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are contemplated in this disclosure.

In the following description, a step module for stairs used in the construction of stairways, typically for multi- floor buildings, will be set forth in detail. The step module can be adjustable and can reduce the cost of and simplify the construction of stairs by permitting adjustment of both riser height and tread width. Thus, the module and resultant stairs can be readily adjusted to suit the conditions (e.g. dimensions, compliance, etc.) of a particular building or construction site.

Figures la to lc depict the components of the step module as well as the main components of the stairs that can be constructed from the step module. Each of the components will be described separately hereafter in further detail.

In Figures la to lc, the stairs 2 comprise a plurality of riser members 4 and tread members 6. The riser members 4 and tread members 6 are located in use between an upper landing tread 8 and a lower landing tread 10. The riser members 4 and the tread members 6 are mounted to at least one or typically two stringers 12.

Although not illustrated, the upper landing tread 8 and/or the lower landing tread 10 of the stairs 2, may be coupled with additional (e.g. second or more) stairs. For example, the stairs 2 can be coupled with additional stairs to change or to extend stair direction and, in one embodiment, the stairs may be orientated perpendicular or at an angle to each other. In another embodiment, the stairs 2 can be orientated at 180° to each other and positioned adjacent to a second (e.g. like) stairs, so as to provide a point of entry to stairs 2 at a position vertically opposite to a point of exit to stairs 2. As shown, the riser member 4 is orientated substantially perpendicular to the tread member 6. Variations can be made to the riser member 4 such that it may be orientated at angles other than perpendicular to tread member 6.

The position of riser member 4 and tread member 6 can be adjusted horizontally and vertically, respectively, for a given site/application and to meet the relevant industry building standards/code. Such adjustments will be explained hereafter in further detail with reference to the embodiments shown and described in each of Figures 2 to 7.

The stairs 2 further comprise opposing stringers 12 (typically a pair of stringers). The stairs 2 may be formed with just one stringer and e.g. an adjacent wall.

Alternatively, the riser members 4 and tread members 6 may be mounted between opposing walls (i.e. instead of stringers).

Typically, each of the riser members 4 and each of the tread members 6 are respectively mounted at respective end edges 18 to the opposing stringers 12 of the module. The stringers 12 may be formed from a metal such as steel or aluminium, as may be the riser members 4 and tread members 6. Other suitable materials may be employed (e.g. timber, composite, etc.).

Each stringer 12 comprises an elongate plate that extends from the upper landing tread 8 to the lower landing tread 10. The stringers 12 are configured to provide structural integrity to the assembled components of the stairs 2. The stringers 12 can e.g. be roll-formed.

Each elongate plate of each stringer 12 can be provided with formations or deformations therein to facilitate the mounting to the stringers 12 of the riser members 4 and tread members 6. Such formations/deformations can be pre- formed at or in the elongate plate of each stringer 12, or they may be formed on site (e.g. once the location of the stairs has been fully measured up). Additionally or alternatively, the riser members 4 and tread members 6 can each be mounted to the elongate plates of the stringers 12 by way of a plurality of fasteners, locking mechanism, lock-and-key alignment, mounting tabs, welding (e.g. spot-welding), etc.

Further, a site may be measured up, with the required measurements and specifications being captured (e.g. electronically such as via an app) and then sent to a remote manufacturing/fabrication facility. At the facility, the stringers 12 can be preformed with a number of suitable formations/deformations for the given remote site. Thus, when a kit including stringers 12, riser members 4 and tread members 6 is shipped to the building/construction site, the stairs can quickly and easily be assembled on site, ready to install.

Stair/Module Embodiment 1 (Figs. 2a&b)

Referring now to the embodiment shown in Figures 2a and 2b, each riser member 4 comprises an elongate plate with flanges 14 and 15 arranged to project from both the in-use lower and in-use upper edge of the plate. The lower flange 14 is configured to abut the in-use substantially horizontal plate of an underlying tread member 6. In Fig. 2a, the upper flange 15 is configured to abut the in-use substantially horizontal plate of an overlying tread member 6. However, in Fig. 2b, the upper flange 15 is configured to be spaced in relation to the in-use substantially horizontal plate of an overlying tread member 6. This spacing does not effect the performance of the stairs.

Initially, such abutment can occur without the use of fasteners, locking mechanism, welding, etc. Further, when the stairs are assembled (i.e. each riser member 4 and tread member 6 has been respectively secured to the opposing stringers 12), there may be no requirement to additionally secure each riser member 4 to one or each adjacent tread member 6. In other words, each riser member 4 and each tread member 6 can be separately and independently mounted to the stringers 12, and not to each other.

The lower flange 14 of each riser member 4 is configured to function as a base that is able to be moved in relation to the underlying tread member 6. For example, and as illustrated by the different positions in each of Figures 2a and 2b, each riser member 4 can be moved horizontally relative to the underlying tread member, thereby adjusting the width of available tread of the tread member 6. As set forth above, this width of available tread can be referred to as the“tread member distance”. Figure 2a shows a wider width of available tread (tread member distance) than that shown in Figure 2b.

Moreover, Figures 2a and 2b show how the riser height can be adjusted by moving a first tread member 6 relative to a second tread member 6’, and/or the second tread member 6’ relative to a second tread member 6”. As set forth above, this ability to vary riser height can be referred to as an adjustable“riser member distance”. Figure 2a shows a shorter riser height (riser member distance) than that shown in Figure 2b.

Such adjustment of the tread member distance and riser member distance can be facilitated by changing the location of mounting of the opposing ends 18 or each of the riser member 4 and tread member 6 at the respective one or more stringers 12. Such changing of the location of mounting can be facilitated by the various riser/tread member-to-stringer mounting mechanisms as outlined above.

Depending on the site, a single set of stairs may have a number of different tread member distances and riser member distances. It will also be seen that the tread member 6 comprises an elongate plate with a flange 16 arranged to project downwards in use from the side (i.e. leading) edge of the plate. The tread member flange 16 gives a‘q’-shape profile to the tread member 6 (e.g. the profile is a“bullnose with a tail”).

When each tread member 6 is mounted to the one or more stringers, typically the flange 16 is located proximal to the upper flange 15 that projects from the upper edge of the riser member 4, as shown in each of Figs. 2a and 2b. In a variation (not shown in Figs. 2a & 2b), each tread member 6 can be mounted to the one or more stringers so that the flange 16 is located above the upper flange 15 (e.g. to be spaced up and away from the riser member 4).

In each of Figs. 2a and 2b, the tread member flange 16 abuts the riser member 4 plate. In other words, a continuous riser surface is defined in the resulting stairs. However, it is to be clearly understood that such abutment is not necessary to an adequate functioning of the stairs.

Furthermore, when a second tread member 6’ is mounted to the one or more stringers 12 such that it assumes the closest possible position to a first tread member 6 (Fig. 2a), the lower 14 and upper 15 flanges of riser member 4 can respectively abut the tread members 6, 6’. As set forth above, once in their desired mounting locations with respect to the one or more stringers 12, the tread member flange 16, tread member 6 and the riser member 4 may additionally be coupled together by way of fasteners, locking mechanism, welding, adhesive, etc. Again, it is to be clearly understood that such coupling together is not necessary to an adequate functioning of the stairs.

While Figures 2a and 2b illustrate one possible embodiment of the profiles of the riser member 4 and tread member 6, further embodiments of the riser member 4 and tread member 6 are shown in and will now be described with reference to each of Figures 3 to 7. A number of these further embodiments generally include the same features as previously described, but differ in that the tread member flanges 16 and riser member flanges 14, 15 are formed with different profile shapes. These different profiles will now be described respectively.

Stair/Module Embodiment 2 (Figs. 3a&b)

Referring now to Figures 3a and 3b, a second embodiment of a step module for constructing the stairs 2 is shown, with the second embodiment differing from the first embodiment shown in Figs. 2a and 2b. Like parts are shown with like reference numbers, but with 100 added thereto. In the second embodiment, the tread member flange 116 has the form a‘c’- shaped (e.g. bullnose) profile, in comparison to the“bullnose with a tail” profile of Figs. 2a and 2b.

Further, in Fig. 3b, the lower flange part of the tread member‘c’-shaped flange 116 is shown generally aligned but located just slightly above upper flange 115 of the riser member 104. It is to be clearly understood that such an arrangement does not compromise an adequate functioning of the stairs.

Other than these differences, the mode of construction and operation of the step module of Figs. 3a and 3b is similar to that described for Figs. 2a and 2b. Stair/Module Embodiment 3 (Figs. 4a&b)

Referring now to Figures 4a and 4b, a third embodiment of a step module for constructing the stairs 2 is shown, with the third embodiment differing from each of the first and second embodiments of Figs. 2a/2b and 3a/3b. Like parts are shown with like reference numbers, but with 200 added thereto. The third embodiment of the step module for stairs 2 differs from each of the first and second embodiments, in that the tread member flange 216 is a plate-like structure that is bent at an angle slightly less than 90° to the main plate of the tread member 206 (i.e. to angle slightly back from a leading edge of the tread member 206). For example, the tread member flange 216 of tread member 206’ is bent so as to project downwards to tread member 206 but backwards from the leading edge of tread member 206’.

Furthermore, the main plate of riser member 204 is formed with only one in-use lower flange 214 that arranged to project from the in-use lower edge of the riser member 204, at an angle slightly greater than 90° to the main plate of the riser member 204.

Typically, the angle between the main plate of riser member 204 and lower flange 214 is such that, when added to the angle between the main plate of tread member 206 and flange 216, this amounts to 180°. This means that the main plate of riser member 204 is able to interface with an inside face of tread member flange 216, as shown in each of Figs. 4a and 4b. This can give the stairs a generally flush appearance.

Other than these differences, the mode of construction and operation of the step module of Figs. 4a and 4b is similar to that described for Figs. 2a and 2b.

Stair/Module Embodiment 4 (Figs. 5a&b)

Referring now to Figures 5a and 5b, a fourth embodiment of a step module for constructing the stairs 2 is shown, with the fourth embodiment differing from each of the first to third embodiments of Figs. 2a/2b, 3a/3b and 4a/4b. Like parts are shown with like reference numbers, but with 300 added thereto.

The fourth embodiment of the step module for stairs 2 comprises a modified riser member 304 and a modified tread member 306. In this regard, the lower flange 314 of riser member 304 is shaped as a recess so as to receive therein a side (trailing) edge of tread member 306. Further, the upper flange 315 is shaped as a step or ledge so as to receive thereon a side (leading) edge of a next uppermost tread member 306’.

In practice, with each of the modified riser members 304 having been secured to the stringer(s) 12, the trailing edge of a given tread member 306’ is first located in the recess defined by the lower flange 314 of a given riser member 304’. The tread member 306’ is then released to pivot (e.g. dropped) such that its leading edge is able to locate on the step or ledge defined by the upper flange 314 of a next lower riser member 304. This process is repeated to install each of the modified tread members 306.

In the fourth embodiment of the step module, the modified tread member 306 can be resized prior to installation in the step module. In this regard, each of the modified riser members 304 can be secured to the stringer(s) 12, and the width of the modified tread member 306 (i.e. tread member distance) can then be adjusted accordingly. This allows the modified tread member 306 to be fabricated on site (e.g. from excess or waste building materials).

For example, the modified tread member 306 can comprise an insert of pre fabricated fibre-cement sheet. The insert could instead comprise a timber sheet, a composite (e.g. fibre-polymer) material, a metal plate, etc. Excess fibre-cement sheet is often readily available at a building site, and is lightweight, strong, and able to be cut and shaped on site. In this regard, a fibre-cement sheet may be cut to simultaneously form a number of tread members 306, each to a selected width, with each then being mounted between respective and adjacent riser members.

Fig. 5a shows modified tread members 306 of narrower width (i.e. shorter tread member distance) than those shown in Fig. 5b. However, each of the modified riser members 304 are consistent between Figs. 5a and 5b, but it should be understood that the height of riser members (i.e. riser member distance) can be varied in a given step module.

Other than these differences, the mode of construction and operation of the step module of Figs. 5a and 5b is similar to that described for Figs. 2a and 2b.

Stair/Module Embodiment 5 (Figs. 6a&b)

Referring now to Figures 6a and 6b, a fifth embodiment of a step module for constructing the stairs 2 is shown, with the fifth embodiment differing from each of the first to fourth embodiments of Figs. 2a/2b to 5a/5b. Like parts are shown with like reference numbers, but with 400 added thereto.

In the fifth embodiment, the step module for stairs 2 is generally the same as the fourth embodiment of Figs. 5a and 5b. However, the main difference is that the upper edge of riser member 404 is not configured with a step or ledge like that shown in Figs. 5a and 5b. Rather, the step or ledge is provided as a separate component 415, with step component 415 able to be independently mounted, at opposite ends, to the stringer(s) 12 of stairs 2.

Further, whilst the riser member 404 comprises a lower flange 414 that is shaped as a recess so as to receive therein a side (trailing) edge of a given tread member 406, the upper step or ledge (i.e. that is present in the fourth embodiment) is replaced with an in-use rearwardly projecting flange 417. Flange 417 is able to be positioned in relation to (i.e. located at (Fig. 6a) or spaced from (Fig. 6b)) the separate step component 415. Notwithstanding the spacing between the flange 417 and the step component 415, such an arrangement does not compromise an adequate functioning of the stairs.

In this way, the distance (i.e. riser member distance) between e.g. a first tread member 406 and an adjacent and overlying second tread member 406’ can be adjusted by moving the intermediate riser member 404 up or down relative to the second tread member 406’. This changes to mounting location of the riser member 404 at the stringer(s) but results in a change in the spacing between the flange 417 and the step component 415 as illustrated in Figs. 6a and 6b.

Again, with each of the step components 415 and riser members 404 having been secured to the stringer(s) 12, the trailing edge of a given tread member 406 is first located in the recess defined by the lower flange 414 of a given riser member. The tread member 406 is then released to pivot (e.g. dropped) such that its leading edge is able to locate on the step or ledge of the step component 415. This process is repeated to install each of the tread members 406.

Again, the tread member 406 can be resized prior to installation in the step module. In this regard, the width of each tread member 406 (i.e. tread member distance) can be adjusted accordingly. As above, this allows the tread member 406 to be fabricated on site (e.g. from excess or waste building materials) such as from fibre-cement sheet, timber sheet, composite (e.g. fibre-polymer) sheeting, metal plate, etc. Fig. 6a shows a tread member 406 of slightly narrower width (i.e. shorter tread member distance) than the tread member 406 shown in Fig. 6b. Further, the height of each of the riser members 404 is consistent between Figs. 6a and 6b, but it should be understood that the riser member distance can be varied in a given step module, as outlined above.

Other than these differences, the mode of construction and operation of the step module of Figs. 6a and 6b is similar to that described for Figs. 2a and 2b.

Stair/Module Embodiment 6 (Figs. 7a&b)

Referring now to Figures 7a and 7b, a sixth embodiment of a step module for constructing the stairs 2 is shown, with the sixth embodiment differing from each of the first to fifth embodiments of Figs. 2a/2b to 6a/6b, although being mostly like the fifth embodiment of Figs. 6a/6b. Like parts are shown with like reference numbers, but with 500 added thereto.

In the sixth embodiment, the step module for stairs 2 generally includes the same features as the fifth embodiment of Figs. 6a/6b, but differs in that the separate step component 515 comprises an additional lower flange 513. The flange 513 projects downwards from a remainder of the step component 515, with the flange configured to interface with a main plate of an adjacent riser member 504.

Again, the riser member flange 517 is able to be positioned in relation to the step component 515. In this regard, the flange 517 can locate at (e.g. abut) the step component 515 (Fig. 7a) or it can be spaced from the step component 515 (Fig. 7b).

In either location, the lower flange 513 can cover the otherwise visible gap in the riser between the adjacent tread members (e.g. 506 & 506’ or 506’ & 506”, etc.). In addition, the flange 513 can give the appearance of a continuous riser member that extends between the adjacent tread members for various riser member differences. Again, the step components 515 and riser members 504 are secured to the stringer(s) 12, and the trailing edge of a given tread member 506 is first located in the recess defined at lower flange 514 of a given riser member 504. The tread member 506 is then released to pivot (e.g. dropped) such that its leading edge is able to locate on the step or ledge of the step component 515. This process is repeated to install each of the tread members 506.

Again, the tread member 506 can be resized prior to installation in the step module. As above, this allows the tread member 506 to be fabricated on site (e.g. from excess or waste building materials) such as from fibre-cement sheet, timber sheet, composite (e.g. fibre-polymer) sheeting, metal plate, etc.

Other than these differences, the mode of construction and operation of the step module of Figs. 7a and 7b is similar to that described for Figs. 2a and 2b.

Stair/Module Embodiment 7 (Fig. 8)

Referring now to Figure 8, a seventh embodiment of a step module for constructing stairs 22 is shown. Like parts are shown with like reference numbers, but with 600 added thereto.

In the seventh embodiment, the step module for the stairs 22 comprises a pair of opposing stringers 612, and a plurality of riser members 604. The riser members employed in the step module for stairs 22 can comprise any one of the riser members shown in Figs. 1 to 7. For example, in Figure 8, riser members 604 are similar to the riser members 304 shown in Figs. 5a & 5b.

In the embodiment of Figure 8, and in place of a plurality of tread members, the stairs 22 comprise a cover plate 601. The cover plate is arranged to form an underside that is located beneath the plurality of riser members 604 and that extends between the opposing stringers 612. Thus, the cover plate 601 forms an enclosed underside of the stairs 22. The resulting enclosure can act as formwork, such that a settable or curable fill material, e.g. concrete, can be poured therein. In this regard, the fill material can be poured (e.g. pumped) into each of the spaces that are defined between a pair of adjacent riser members 604, the stringers 612 and the cover plate 601. Once poured into these respective spaces, the fill material can be formed (e.g. screeded, trowelled, etc.) into respective treads of the stairs 22. In other words, the step module of Fig. 8 is able to act as a formwork for e.g. concrete stairs.

Referring now to Figure 9, the step module embodiment of Fig. 8 is shown in use for constructing stairs 722 in a modular pod 703. The modular pod 703 comprises wall infill panels 705 and is suitable for use as permanent formwork in the construction of a stairwell comprising a stairway, a lift well shaft or similar structure within a building. The modular pod can integrate with the floor of a building, and floor and pod concrete can be poured simultaneously.

In Fig. 9, each step module is labelled 722’ and 722”. The‘upper’ step module 722’ is shown extending downwardly from an upper landing 708, down to a lower

(intermediate) landing 710. The‘lower’ step module 722” is shown extending downwardly from the intermediate landing 710.

The upper landing 708 comprises a base tray 724 and side walls 712 that extend up from and surround the base tray. The upper landing 708 also comprises a number of bracing members in the form of transverse cross-members 720.

The lower landing 710 comprises a base tray 725 and side walls 714 that extend up from and surround the base tray. The lower landing 710 also comprises a number of bracing members in the form of transverse cross-members 721.

The upper landing 708 and lower landing 710 each thereby define a tray into which an infill material such as concrete may be poured. When so poured, the transverse cross-members 720 and 721 become embedded in the concrete and thereby also act as reinforcing bars. Each step module 722’ and 722” can comprise any one of the components shown in Figure 8, where additional like parts are shown with like reference numbers, but with 700 added thereto.

The upper landing 708 is connected to the structural components of the modular pod 703 and can itself act as bracing within the pod. Likewise, the lower

(intermediate) landing 710 is connected to the structural components of the modular pod 703 and can also act as bracing within the pod.

The upper stair set 722’ is connected (e.g. spot welded, fastened) to each of the upper landing 708 and lower (intermediate) landing 710. The lower stair set 722” is connected (e.g. spot welded, fastened) to the lower (intermediate) landing 710 and extends downwardly therefrom. A lower end of the lower stair set 722” can be connected (e.g. spot welded, fastened) to a lower frame of the modular pod 703 as shown.

The entire resulting structure shown in Fig. 9 can act as formwork, such that a settable or curable fill material, e.g. concrete, can be poured therein. In this regard, the fill material can be poured (e.g. pumped) into each of the spaces that are defined at the upper 708 and lower 710 landings, the upper 722’ and lower 722” step modules, and within the wall infill panels 705. Once poured into these respective spaces, the fill material can be formed (e.g. screeded, trowelled, etc.) at the upper 708 and lower 710 landings, and at the upper 722’ and lower 722” step modules.

The continuous flow of concrete can be poured during concrete pouring of an overlying floor in a building, such that the concrete can be used to form the floor, the walls of the modular pod, the upper and lower landings, and upper and lower stairs at the step modules, i.e. the overlying floor concrete is poured

simultaneously and contiguously with the modular pod concrete and all sub structures contained therein. Variations and modifications may be made to the step module as previously described without departing from the spirit or ambit of the disclosure.

In the claims which follow and in the preceding description of the step module, except where the context requires otherwise due to express language or necessary implication, the word“comprise” or variations such as“comprises” or

“comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the step module.

Claims (36)

1. An adjustable step module for stairs, the adjustable step module comprising: a first elongate tread member having first and second spaced-apart edges and a surface extending between the first and second edges, one of the first and second edges being configured to form a distal edge of the first tread member in use, the first tread member able to be spaced below a second elongate tread member in the stairs in use; a first elongate riser member having first and second spaced-apart edges and a surface extending between the first and second edges, the riser member configured to be arranged substantially perpendicular to the first tread member, and such that the riser member can be arranged between the first and second tread members in use; wherein a tread member distance is defined as the distance between the in- use substantially perpendicular riser member and the distal edge of the first tread member, the module being configured such that the tread member distance is adjustable; and wherein a riser member distance is defined as the distance between the first and second tread members, the module being configured such that the riser member distance is also adjustable.

2, An adjustable step module according to claim 1 wherein the tread member distance is able to be adjusted by moving the riser member along the first tread member to one of a plurality of locations intermediate the first and second tread member edges.

3. An adjustable step module according to claim 2 wherein the riser member comprises a plate which is arranged to extend substantially perpendicularly to the first tread member in use, and a flange arranged to project from an in use lower edge of the plate and away from the distal edge in use, the flange configured to function as a base that is able to be moved along the first tread member to one of the plurality of locations intermediate the first and second tread member edges.

4. An adjustable step module according to claim 1 wherein the tread member distance is able to be adjusted by changing the distance between the first and second tread member edges.

5. An adjustable step module according to claim 4 wherein the tread member distance is able to be adjusted by providing a tread member insert that is configured for mounting between the first and second riser members, wherein the first edge-to-second edge width of the tread member insert is selected prior to mounting the tread member insert between the first and second riser members.

6. An adjustable step module according to claim 5 wherein the first riser member comprises an in-use upper recess and the second riser member comprises an in-use lower recess, the recesses being arranged to receive therein a respective edge of the tread member insert to thereby mount the tread member insert between the first and second riser members.

7. An adjustable step module according to claim 6 wherein the upper recess of the first riser member is: integrally formed with a remainder of the first riser member, the recess in use extending along an in-use upper edge of the first riser member; separately formed as a separate component to a remainder of the first riser member, the recess in use being arranged in relation to an in-use upper edge of a remainder of the first riser member.

8. An adjustable step module according to claim 6 or 7 wherein the lower recess of the second riser member is integrally formed with a remainder of the second riser member, the lower recess in use extending along an in-use lower edge of the second riser member.

9. An adjustable step module according to any one of claims 6 to 8 wherein each riser member comprises in-use upper and lower recesses, each arranged to receive therein a respective edge of the tread member insert.

10. An adjustable step module according to any one of claims 5 to 9 wherein the tread member insert comprises a fibre-cement sheet.

11. An adjustable step module according to claim 10 wherein the fibre-cement sheet is able to be cut to a selected width prior to mounting the tread member insert between the first and second riser members.

12. An adjustable step module according to any one of the preceding claims wherein the riser member distance is able to be adjusted by moving the second tread member with respect to the first riser member to one of a plurality of locations.

13. An adjustable step module according to claim 12, wherein the riser member distance is adjusted by moving the second tread member in use up or down with respect to the first riser member and the first tread member.

14. An adjustable step module according to claim 12 or 13 wherein a distal edge of the second tread member comprises an in-use downwardly projecting flange, and wherein when the second tread member is moved with respect to the first riser member, the distal flange moves with respect to the first riser member.

15. An adjustable step module according to claim 12 or 13 wherein the first riser member comprises an in-use upper component that is separately formed to a remainder of the first riser member, and wherein when the second tread member is moved with respect to the first riser member, the first riser member upper component also moves with respect to the remainder of the first riser member.

16. An adjustable step module according to claim 15 wherein the first riser member upper component comprises an in-use downwardly projecting flange, and wherein when the second tread member is moved with respect to the first riser member, the upper component flange moves with respect to the remainder of the first riser member.

17, An adjustable step module according to any one of the preceding claims, the module comprising a plurality of riser members and a plurality of tread members, the module further comprising opposing stringers, wherein one or more of the riser members and/or one or more of the tread members are each

respectively mounted at respective end edges to the opposing stringers of the module.

18, An adjustable step module according to claim 17, wherein the plurality of riser members and plurality of tread members are each independently mounted at their respective end edges to the opposing stringers of the module.

19, A step module for stairs, the step module comprising an elongate tread member, and first and second elongate riser members, the second riser member being arranged in the stairs above the first riser member in use; - the tread member being configured for mounting between the first and second riser members, wherein a width of the tread member from one side edge to an opposing side edge is able to be selected prior to mounting the tread member between the first and second riser members; the first riser member having spaced-apart in-use upper and lower edges and a surface extending between the upper and lower edges, the upper edge being configured to support said one side edge of the tread member thereat; the second riser member having spaced-apart in-use upper and lower edges and a surface extending between the upper and lower edges, the lower edge being configured to support said opposing side edge of the tread member thereat.

20, A step module according to claim 19 wherein the tread member comprises a fibre-cement sheet.

21, A step module according to claim 20 wherein the fibre-cement sheet is able to be cut to a selected width prior to mounting the tread member between the first and second riser members.

22, A step module according to any one of claims 19 to 21 wherein the upper edge of the first riser member is configured as a step or ledge so as to support thereon said one side edge of the tread member.

23, A step module according to any one of claims 19 to 22 wherein the lower edge of the second riser member is configured as a recess that extends along the lower edge, the recess arranged to receive and support therein said opposing side edge of the tread member.

24, A step module according to any one of claims 19 to 23, the step module comprising a plurality of tread members and a plurality of corresponding riser members for supporting therebetween a respective tread member.

25, A step module according to any one of claims 19 to 24 wherein each of the riser members comprises an upper edge that is configured to support said one side edge of a respective tread member thereat, and a lower edge that is configured to support said opposing side edge of a respective tread member thereat.

26. A step module according to any one of claims 19 to 25, the step module further comprising opposing stringers, wherein each of the riser members is mounted at respective end edges to the opposing stringers.

27. A step module according to claim 24 wherein, in place of the plurality of tread members, the step module comprises a cover plate, the cover plate being arranged in use to form an underside beneath the plurality of riser members.

28, A step module according to claim 27, the step module further comprising opposing stringers, wherein each of the riser members is mounted at respective end edges to the opposing stringers, and wherein the cover plate is arranged in use to extend between the opposing stringers so as to form an enclosed underside of the riser members.

29. A step module according to claim 27 or 28, the step module being configured whereby a fill material, such as concrete, can be arranged in a space that is defined between the plurality of riser members and cover plate, whereby the fill material can be formed into respective treads of the step module.

30. A step module according to any one of claims 27 to 29, the step module further comprising an in-use upper landing and/or lower landing, the upper landing arranged at an in-use upper end of the stairs, the lower landing arranged at an in-use lower end of the stairs, each landing being configured whereby a fill material, such as concrete, can be arranged at the landing.

31. A step module according to claim 30, wherein each landing comprises a tray, each tray having one or more side walls that extend up from and surround a base of the tray, each tray optionally comprising one or more bracing members that extend from the one or more side walls between one side of the tray and an opposing side of the tray.

32, A step module according to claim 30 or 31, when dependent on claim 29, wherein each tray is configured to receive therein the fill material, such as concrete, when the fill material is arranged to form the respective treads of the step module.

33, A step module for stairs, the step module comprising an elongate cover plate, and a plurality of in-use spaced apart elongate riser members, the cover plate being arranged in use to form an underside beneath the plurality of riser members.

34, A step module according to claim 30, the step module further comprising opposing stringers, wherein each of the riser members is mounted at respective end edges to the opposing stringers, and wherein the cover plate is arranged in use to extend between the opposing stringers so as to form an enclosed underside of the riser members.

35. A step module according to claim 30 or 31, the step module being configured whereby a fill material, such as concrete, can be arranged in a space that is defined between the plurality of riser members and the cover plate, whereby the fill material can be formed into respective treads of the step module.

36. A step module according to any one of claims 33 to 35, the step module further comprising an in-use upper landing and/or lower landing, the or each landing being configured as set forth in any one of claims 30 to 32, whereby the or each landing may receive therein fill material, such as concrete, when the fill material is arranged to form the respective treads of the step module.