DOCKET NO: WA004 SAFETY INSTALLATION FIELD OF THE INVENTION This invention relates to safety installations and in 5 particular, though not exclusively to safety installations at cool rooms of retail premises and the like. BACKGROUND OF THE INVENTION A cool room is a refrigerated room within a larger, O typically taller, premises that provides a warehouse space. Predominantly for efficiency reasons, the cool room is made to be of only the size required for storage of items requiring refrigeration. This minimizes the refrigerated area, thereby reducing energy costs. Because there is often a space between 5 the roof of the cool room and the ceiling of the larger warehouse space, the space above the cool room can become attractive for storage of items. However, the cool room is often not made to the structural standards of the rest of the premises and therefore problems can arise if the cool room roof 0 is subjected to excessive loads from above. When people stand on top of the cool room there is also the risk that they can fall off the cool room and onto the floor below. What is required is a system and method for preventing storage on the cool room roof. 5 SUMMARY OF THE INVENTION In one aspect of the disclosure, there is provided a cool room structure for a cool room disposed within a premises such that a space exists above a cool room roof surface and below a 0 ceiling of the premises. The cool room structure may include a plurality of support members secured at intervals to the cool room roof surface substantially adjacent an edge of the cool 1 DOCKET NO: WA004 room roof surface. One or more of the support members may include a base member including a substantially horizontal underside for abutting the cool room roof surface and an upright member extending upwards of the base member. The installation 5 may also include at least one barrier member secured to at least two of the plurality of support members such that the at least one barrier member spans a gap between the at least two support members. In one aspect of the disclosure, there is provided a method 0 for securing a space above a cool room roof surface including erecting a plurality of supports at intervals substantially adjacent at least one edge of a cool room roof, the supports including a base member configured to be secured against the cool room roof surface and an upright member extending upwards 5 of the base member; and securing one or more barrier members to the plurality of supports such that the one or more barrier members span the intervals between the plurality of supports. In one aspect of the disclosure, there is provided a kit for a cool room safety installation including a plurality of 0 prefabricated support members configured to be secured at intervals to a cool room roof surface substantially adjacent an edge of the cool room roof surface. One or more of the prefabricated support members may include a base member including a substantially horizontal underside for abutting the 5 cool room roof surface and an upright member that when attached to the base member extends upwards of the base member. The installation may also include at least one barrier member configured to be secured to at least two of the plurality of prefabricated support members such that the at least one barrier 0 member spans a gap between the at least two prefabricated support members. 2 DOCKET NO: WA004 BRIEF DESCRIPTION OF THE DRAWINGS Reference will now be made, by way of example only, to specific embodiments and to the accompanying drawings in which: Figure 1 shows a premises with a cool room and trading 5 floor within; Figure 2 shows a cool room featuring a safety installation; Figure 3 shows a side view of a support of the safety installation; Figure 4 shows a end view of the support in partial cross o section; Figure 5 shows a gate in a barrier member; Figure 6 shows the attachment of the support member to a cool room roof; and Figure 7 shows a conduit passing over a support member. 5 DETAILED DESCRIPTION OF THE INVENTION In Figure 1, there is schematically shown a premises 10 including a floor 12, walls 14 and ceiling 16 that define a warehouse space 11. The premises 10 may be a standalone 0 warehouse or may be a retail premises including a trading floor 18 such as a supermarket where items from the warehouse space 11 are sold. Typically, the trading floor 18 features a suspended or plaster ceiling 19 that is unable to support any weight from above. 5 Within the warehouse space 11 and adjacent the trading floor 18 is a cool room 20. The cool room 20 includes a plurality of walls 24 constructed on the warehouse floor 12. The cool room walls 24 support a cool room roof 26 which has an inner ceiling 27 for the cool room 20 and an outer roof surface 0 28. 3 DOCKET NO: WA004 The cool room 20 is typically only as large as is required to provide the refrigeration storage needs, such as for the adjacent retail premises. In order to keep the refrigerated space to a minimum, the height of the cool room 20 is typically 5 less than the height of the premises 10. A gap 29 therefore exists between the cool room roof surface 28 and the premises ceiling 16. The roof surface 28, being a relatively large, horizontal surface can become an attractive surface for the storage of 0 items. Figure 2 shows a perspective view of a cool room 20 adjacent a trading floor 18 of the premises 10. For the sake of clarity, the warehouse walls and ceiling have been omitted. In order to prevent the storage of items in the space 29 above the 5 cool room 20, a safety installation 30 may be provided. The safety installation 30 can include a plurality of supports 31. As shown in Figure 3, the supports 31 may each include a base member 32 that can be secured to the outer roof surface 28 of the cool room roof 26 by any suitable means such as bolts, 0 screws, etc. The support 31 further includes an upright member 33 that extends substantially perpendicularly to the base member 32. The supports 31 are located at intervals along the edges of the cool room roof 26 such that the upright members 33 extend upward of the cool room roof 26. One or more barrier members 35 5 are secured to the supports so that the barrier members span the gap between the supports. While fencing mesh is the preferred material for the barrier member in one particular embodiment, in other embodiments, alternative materials may be used such as wire strands, Perspex sheets, chain mesh fencing, timber 0 cladding, steel cladding or other suitable barrier materials. The barrier members 35 are secured against the upright members 33 of the supports 31 along the edges of the cool room. 4 DOCKET NO: WA004 The barrier members 35 may be secured to the upright members 33 by any suitable means such as staples, clips, u-bolts, screws, welding and brackets, etc. Once installed, the barrier members 35 span the interval between the supports 31, thereby preventing 5 access to the space 29 above the cool room. If access to the space 29 is required, such as for routine maintenance, then a gate or similar entryway may be installed as shown in Figure 5. The gate 37 may have a frame 38 provided in the barrier member 35 that is secured to one of the uprights 33 or an adjacent 0 barrier length by any suitable means such as hinges (not shown). The gate may include a lock 39, such as a padlock and bolt arrangement. A ladder or stairs (not shown) may be provided on the cool room walls to provide access to the gate 37. The gate 37 is preferably, though not essentially, made to open inward to 5 the above cool room space 29. The supports 31 will now be described with reference to Figure 3, which shows a side view of the support 31 and to Figure 4, which shows an end view in partial cross section. The base member 32 of the supports may include a lower plate 41 0 extending upward from which are two side plates 42, 43. Each side plate 42, 43 further includes an outwardly extending flange 44, 45 that extends substantially horizontally from the upper edge of the respective side plate. In an alternative embodiment, the flanges 44, 45 may extend outward and downward. Apertures 47 5 may be drilled, punched or otherwise preformed into the lower plate 41 to provide bolt holes for later attachment of the base member 32 to the cool room roof 26. In an alternative embodiment, the apertures 47 may be formed onsite to allow optimal placement of the fastenings for the base members 32. The 0 base member 32 may be an extruded metal or plastic or fibre reinforced plastic or may be press formed. Alternatively, the lower plate, side plates and flanges may be made from separate 5 DOCKET NO: WA004 pieces. Without limitation, suitable materials for the base member include various materials such as stainless steel metal or aluminium metal or steel. A person skilled in the art will recognize that other materials will be suitable. 5 The upright members 33 may be sized to fit in the gap between the side plates 42, 43 of the base member and are retained in place by bolts or tek screws 48. Without limitation, suitable materials for the upright members 33 include stainless steel, mild steel, aluminium, wood etc. A person skilled in the 0 art will recognize that other materials will be suitable. In an alternative embodiment, the upright 33 may include a sleeve, slot or similar recess that receives the base member 32 within it, with the base member and upright being secured by bolts, screws, adhesives or the like. A person skilled in the art will 5 recognize that other methods for securing the base member 32 to the upright 33 are possible and all such methods are intended to be encompassed herein. To provide additional strength and rigidity to the supports 31, a diagonal cross brace 45 may be provided between the base O member 32 and the upright 33. The cross brace 45 is omitted in Figure 4 for clarity. In one embodiment, the supports 31 may be completely prefabricated and assembled. In an alternative embodiment, the components of the supports 31, optionally including any 5 fasteners, may be prefabricated and provided in kit form for ease of transport. The prefabricated base member 32, upright 33 and cross brace 45 may then be assembled on site to form each support 31. Figure 6 shows the base member 32 secured to the cool room 0 roof 26. A hole 51 is drilled through the cool room roof 26. A bolt 52 is inserted into the hole 51 from the ceiling side 27 upward (or, alternatively, from the roof surface side 28) . The 6 DOCKET NO: WA004 bolt 52 is pushed through the holes 47 in the lower plate 41 of base member 32. A nut and washer 53 can then be used on the bolt 52 to fasten the base member 32 to the cool room roof 26. Sealants may also be applied to the fastening as necessary. 5 Alternatively, rivets may be used or some other adhesive product. Figure 7 shows the safety installation disposed on a cool room roof. Where there are conduits 61, the conduit 61 may be lifted up and the base member 32 inserted under the conduit 61. 0 The flanges 44, 45 on the base member 32 provide a stable and flat surface that reduces any sharp edges that may sever or otherwise damage the conduit 61. The supports 31 are preferably, though not essentially, fixed substantially adjacent the edges of the cool room roof. In 5 one embodiment, the base member 32 is secured at less than 200mm from the edges of the cool room to prevent any storage space being available on the cool room roof surface 28 and to prevent the ability to stand on the edge of the cool room. The installation 30 preferably extends up to approximately 900mm 0 high, and more preferably 1800mm high, if the gap 29 above the cool room roof 26 allows. At these heights, the installation 30 will typically meet the requirements of serving as a fall protection barrier under Australian Safety Standard AS/NZS1657 1992 for the drop between the cool room roof 26 and the premises 5 floor 12. It is noted that the safety installation need not extend around the entire perimeter of the cool room roof. For example, as shown in Figure 2, the cool room 20 may be adjacent to a trading room 18 featuring a suspended or plaster ceiling 19. On 0 the edges adjacent the trading floor ceiling 19, a conventional safety railing may be used to prevent persons on the cool room roof from walking on the trading floor ceiling 19. In one 7 DOCKET NO: WA004 embodiment, the safety installation 30 is erected along each edge of the cool room roof that represents a fall hazard to persons on the cool room roof 26. In one embodiment, the safety installation 30 may be 5 provided as a kit including a number of the prefabricated supports and a number of barrier member lengths. Attachments for securing the supports to the cool room roof and for securing the fencing lengths to the supports may also be provided. Advantages of the presently described installation include 0 that the installation is not structurally dependent on the roof of the premises because it does not need to extend to the roof, only far enough to a) prevent storage on top of the cool room and b) prevent fall hazards. The installation can be manufactured off-site, reducing risk to food contamination under 5 food hygiene requirements. Although embodiments of the present invention have been illustrated in the accompanied drawings and described in the foregoing description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of 0 numerous rearrangements, modifications, and substitutions without departing from the spirit of the invention as set forth and defined by the following claims. 5 8