AU2011200711A1 - Fall Arrest System - Google Patents

Abstract

- 23 Abstract A fall arrest system 10 installed in a building 11 under construction. The fall arrest system provides a safety barrier which can arrest the fall of a person or piece of equipment from a roof space within the building construction. In this way, the 5 safety barrier prevents or at least retards the fall prior to the falling person or equipment hitting the floor below or any personnel working within the building construction. The building 11 comprises perimeter walls 13 and internal walls 15. The building construction 11 further includes ceiling joists 23. The fall arrest system 10 comprises a fall arrest barrier 30 positioned on the upper side of the 10 ceiling joists 23 and resting on the ceiling joists. The barrier 30 is defined by barrier material configured as mesh netting. The barrier 30 comprises a plurality of barrier sheet sections each configured as a strip 31. The strips 31 are oriented to extend cross-wise over the ceiling joists 23. In other installation arrangements, the strips 31 may extend lengthwise along the ceiling joists 23. The strips 31 are 15 positioned in side-by-side relation to form the barrier 30, with adjacent strips 31 being connected together at junctions 33 to provide integrity to the barrier 30. The strips 31 are anchored to the ceiling joists 23, and optionally any intervening supporting beams, at anchoring points 34 by anchoring elements 35. CUf co) ----- -- L -- ---- L - -..-..... ... .... IL.... - B....LI....LI... . .-...... L A1...14J...L--.L ...A ..... ., - I t L .m .. , t -....... r---..-.T.----.r.--.-.T..--- m -------- as---- ..... I.I . . - UI....A .. I ... I.L...t....L)...- .. I. j --- I.... ...A ...j ----.... ...... . ............ Z: S ... C)t ------- ---------------- ----- -3----- --------,-- -- -- I ----nIL ---- I ---- I - --- t-1-- - t------ I.. ..I...I.. .. I..I----w--L. I r-- 4 -- -- --- 4 ---- -- --------r- -------- a 04 2 --- t --- 1 ----- -I,---- -t ----- ~ ~ ~ C -C--I-- --I --4T.. .. .. T----- --I---v It -- - -. .. -- ---t)- - -- -- --1. -- .. . -

Description

P/00/011 28/5/91 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Name of Applicants: Donald W Hayman Jennifer Jane Leeming Stephen McCann Actual Inventors James Donald Hayman -and Jennifer Jane Leeming Address for service is: WRAYS Ground Floor, 56 Ord Street West Perth WA 6005 Attorney code: WR Invention Title: Fall Arrest System The following statement is a full description of this invention, including the best method of performing it known to me: 1 Fall Arrest System Field of the Invention This invention relates to a fall arrest system for a building under construction. The invention also relates to a method of installation of such a fall arrest system. 5 Background Art The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application. 10 Building construction sites can present dangers to personnel working at elevated locations. One such location which presents a particular danger is the roof area of a building under construction. It is known to install a safety barrier system about the roof perimeter of a building under construction to reduce the likelihood of construction workers falling from the 15 roof area. Such a permitter safety barrier is, however, only effective in preventing falls outwardly of the building perimeter. It is not effective in preventing falls through the roof space into the interior region of the building under construction. A building under construction is vulnerable to interior falls at various stages of the construction process including, for example, during erection of roof framing, 20 installation of roofing materials such as tiles or roof sheeting, and installation of services such as electrical cabling and plumbing within the roof space. The present invention seeks to provide a system which can arrest internal falls from the roof area of a building under construction and also a method for installation of such a system. 25 Disclosure of the Invention According to a first aspect of the invention there is provided a fall arrest system for a building under construction having frame members and an internal space within -2 the building defined below the frame members, the fall arrest system comprising a barrier spanning the frame members. The barrier may comprise a single barrier sheet or a plurality of barrier sheets cooperating to provide the barrier. 5 With this arrangement, the fall arrest system provides a safety barrier above the internal space. In this way, a fall of a construction worker or any construction equipment from a location above that internal space can be arrested by the barrier. The safety barrier need not necessarily prevent the fall but rather arrest the fall in the sense of at least retarding the fall prior to the worker or construction 10 equipment hitting the floor below or any personnel working within the internal space. The barrier may be positioned above or below the frame members, or may be arranged to be disposed above some frame members and below other frame members. 15 The frame members may form part of a frame construction, and the barrier may be attached to the frame construction. By way of example, the frame construction may comprise a peripheral frame element on which the frame members are supported. In certain embodiments, the barrier may be attached to the peripheral frame. The frame construction may comprise two such peripheral frame elements 20 between which the frame members extend to be supported thereby, and the barrier sheet may be attached to both peripheral frame elements. In other embodiments, the barrier is not attached to the peripheral frame element or elements, but rather only to the frame elements. The barrier may be fixed to the frame elements at its marginal edge portions, with the interior region of the barrier 25 not being fixed in any way or alternatively being fixed to a limited extent, such as for example at intervals along junctions between adjacent strips which cooperate to form the barrier. This manner of fixing allows to interior region of the barrier to move relative to the frame members (typically by sliding over the frame members) to progressively arrest a fall.

-3 In one particular arrangement, the frame members may comprise ceiling joists supported on, and extending between, wall plates of a roof construction. The barrier may be attached to at least some of the frame members at spaced intervals. 5 Typically, the frame members are supported between two sections of the building under constructions. In one arrangement, the two sections may comprise walls. More particularly, the two sections may comprise two opposed walls. In another arrangement, the two sections may comprise two beams. In yet another arrangement, the two sections may comprise a beam and a wall. Other 10 arrangements are, of course, also possible. Preferably, the barrier sheet extends between the two sections. In one arrangement, the barrier sheet may be draped over the two sections to extend therebetween. In another arrangement, the barrier sheet may extend between, but terminate inwardly of, the two sections. 15 Preferable, the barrier sheet is pliant. The barrier sheet may comprise netting. The netting may be of a knitted construction formed from high density polyethylene. The barrier sheet may incorporate reinforcement. The barrier sheet may be in strip form. This facilities storage and handling in roll 20 form. With such an arrangement, strips defined by lengths of the barrier sheet may be positioned in side-by-side relation to provide the safety barrier. Adjacent strips may be interconnected. In one arrangement, adjacent strips may be in overlapping arrangement, with the overlapping sections connected together. The 25 overlapping sections may be connected together in any suitable way, such as by anchoring elements installed in spaced apart relation along the length of the overlap to fix the overlapping strips to the frame elements.. When the barrier sheet is in strip form, the reinforcement may comprise one or more reinforcement bands extending along the strip.

-4 When in strip form, the barrier sheet is preferably installed in an orientation such that its longitudinal extent is transverse to the direction of the frame members. The barrier sheet may be adapted to progressively yield while under load during the arrest of a fall. This may be accomplished by providing one or more pleats 5 within the sheet, with the, or each, pleat being adapted to unfold when the sheet is subjected to a load of a certain magnitude. Typically, the or each pleat would be retained in place by bonding or stitching which would release when the sheet is subjected to the load. There may be a plurality of pleats arranged to release at different loadings. The or each pleat may be configured as a series of fold 10 sections which wind back and forth and are disposed one upon another , with the various fold sections being stitched or otherwise bonded together as a unit. In one arrangement, the barrier may be fixed in position by anchoring elements. The anchoring elements may be removable for reuse. Each anchoring element may comprise a body presenting a broad face for 15 location against the barrier sheet, the face being configured for gripping engagement with the barrier sheet. The anchoring element may be adapted to be fastened to a respective surface to clamp the barrier between the broad face and the surface to which the anchoring element is attached. 20 The anchoring element may be adapted to be attached to the surface by at least one fastener passing through the body. The body may incorporate a hole to receive the fastener. Typically, the body is adapted to receive to fasteners. The body may incorporate a sacrificial portion about the hole to receive the head 25 of the fastener, the sacrificial portion having a thickness to permit multiple uses. In one arrangement, the frame members may comprise ceiling frame members. With this arrangement, the frame members may comprise ceiling joists.

-5 In another arrangement, the frame members may comprise roof frame members. With this arrangement, the roof frame members may comprise roof trusses having bottom chords to which the sheet of barrier material is attached. In yet another arrangement, the frame members may comprise both ceiling frame 5 members and bottom chords of roof trusses. According to a second aspect of the present invention there is provided a fall arrest system for an internal space within a building under construction, the internal space being defined below frame members, the fall arrest system comprising a barrier sheet spanning the frame members. 10 According to a third aspect of the invention there is provided a building construction incorporating a fall arrest system according to the first or second aspect of the invention. According to a fourth aspect of the present invention there is provided a method of installing a fall arrest system according to a first or second aspect of the invention. 15 According to a fifth aspect of the present invention, there is provided a method of installing a fall arrest system in a building under construction comprising a plurality of frame members, the method comprising the following steps: providing a strip of barrier material; and installing the strip on the frame members to provide at least part of a fall arrest barrier. 20 According to a sixth aspect of the present invention, there is provided a method of installing a fall arrest system in a building under construction comprising a plurality of frame members extending in a first direction, the method comprising the following steps: providing a strip of barrier material; and installing the strip across the frame members to provide at least part of a fall arrest barrier. 25 According to a seventh aspect of the present invention, there is provided a method of installing a fall arrest system in a building under construction comprising a plurality of frame members extending in a first direction, the method comprising the following steps: providing a strip of barrier; and installing the strip lengthwise along the frame members to provide at least part of a fall arrest barrier.

-6 Where the strip is installed across the frame members, the strip is preferably installed such that its longitudinal extent is in a second direction substantially normal to the first direction. Preferably, the step of installing the strip on the frame members to provide a fall 5 arrest barrier includes anchoring the strip in position in the building. Where the frame members comprise ceiling joists supported between two wall plates, the strip may be anchored to the two wall plates or merely to the ceiling joists. Additionally or alternatively, the strip may be anchored to wall plates extending parallel to the ceiling joists. The barrier may be affixed to the wall 10 plates at spaced intervals along the respective wall plates. The barrier may be fixed to the ceiling joists at its marginal edges, with the interior region of the barrier not being fixed in any way. Preferably, the method further comprises installing one or more further strip across the frame members, wherein the strips cooperate to define the fall arrest 15 barrier. Preferably, the strips are installed in side-by-side relation and wherein the method further includes interconnecting adjacent strips. The adjacent strips may be in overlapping arrangement, with the overlapping sections connected together. 20 The strips of barrier material may be obtained from a roll of barrier material. The method may comprise positioning the roll of barrier material at a nearby location, drawing a strip of barrier material from the roll and passing the strip as it is being drawn from the roll into position over the frame members. The strip of barrier material may be cut or otherwise severed from the roll once in 25 position over the frame members. According to an eighth aspect of the present invention, there is provided a fall arrest system for a building under construction having frame members, the fall -7 arrest system comprising a sheet of barrier material disposed above but positioned on the frame members. According to a ninth aspect of the present invention, there is provided a fall arrest system for a building under construction having frame members, the fall arrest 5 system comprising a sheet of barrier material attached to the underside of the frame members. According to a tenth aspect of the present invention, there is provided a method of installing a fall arrest system in a building under construction having two sections, the method comprising draping a sheet of barrier material over the two sections to 10 extend therebetween, installing fame members above the sheet of barrier material draped between the sections, and attaching the sheet of barrier material to the underside of the frame members. According to an eleventh aspect of the present invention there is provided an anchoring element for a fall arrest system according to any of the previous 15 aspects of the invention. According to an twelfth aspect of the present invention there is provided anchoring element comprising a body presenting a broad face for location against a barrier for fixing the barrier to a frame element of a building under construction to provide a fall arrest system, the face being configured for gripping engagement with the 20 barrier. Brief Description of the Drawings The invention will be better understood by reference to the following description of several specific embodiments thereof as shown in the accompanying drawings in which: 25 Figure 1 is a schematic plan view of a building under construction and a fall arrest system according to a first embodiment installed in the building under construction; -8 Figure 2 is a plan view of the building construction depicted in Figure 1 prior to installation of the fall arrest system according to the first embodiment, illustrating in particular ceiling joists and supporting beams; Figure 3 is a schematic fragmentary sectional elevational view of the fall 5 arrest system according to the first embodiment installed in the building under construction; Figure 4 is a view of part of Figure 3; Figure 5 is a schematic detail view of part of the fall arrest system depicted in Figure 1, the detail view being of the circled part of Figure 1; 10 Figure 6 is a schematic fragmentary plan view of a corner portion of the fall arrest system depicted in Figure 1, illustrating in particular anchoring elements for attachment of barrier material in position; Figure 7 is a sectional side view of one anchoring element installed in position to attach the barrier material to a frame member; 15 Figure 8 is a perspective view of the anchoring element; Figure 9 is an underside plan view of the anchoring element; Figure 10 is a side view of the anchoring element; Figure 11 is a plan view of the anchoring element; Figure 12 is a sectional side view of the anchoring element along line 12-12 20 of Figure 11; Figure 13 is a fragmentary view of a gripping configuration provided on the lower face of the anchoring element; Figure 14 is a schematic side view of a junction between two barrier strips; Figure 15 is a schematic perspective view depicting installation of the fall 25 arrest system according to the first embodiment; -9 Figure 16 a schematic view illustrating installation of barrier material to provide the fall arrest system according to the first embodiment, the barrier material being supplied in roll form; Figure 17 is a schematic fragmentary side view of a fall arrest system 5 according to a second embodiment, illustrating in particular the barrier having reinforcement and an anchoring element fixing the barrier to a frame member at the location of the reinforcement; Figure 18 is a schematic elevational view of a barrier positioned in a building under construction, the barrier forming part of a fall arrest system 10 according to a third embodiment; Figure 19 is a schematic elevational view of the fall arrest system according to the fourth embodiment after installation in the building under construction; and Figure 20 is a schematic elevational view of a fall arrest system according 15 to a fourth embodiment installed in a building under construction. Best Mode(s) for Carrying Out the Invention Referring to Figure 1 to 16 of the drawings, there is shown a fall arrest system 10 according to the first embodiment installed in a building 11 under construction. The building 11 comprises perimeter walls 13 and internal walls 15. In the 20 arrangement shown, the perimeter walls 13 comprise cavity walls constructed of an outer leaf 17, an inner leaf 18 and a cavity 19 therebetween. The invention is, of course, also applicable to buildings having other wall constructions. Wall plates 21 are located at the top of the inner leaves 18 and also the top of the internal walls 15, as is conventional building construction practice. Typically, the 25 wall plates 21 are of timber. The building construction 11 further includes ceiling joists 23 extending between opposed walls, as is conventional practice. The ceiling joists 23 may extend between two opposed external walls, between an external wall and an internal wall, or between two internal walls, according to the design of the building.

-10 Sheeting 24 is attached to the underside of the ceiling joists 23 to provide a ceiling. The building construction 11 also includes roof framing 25 which defines an internal roof space 27. 5 The perimeter walls 13 and the internal walls 15 variously cooperate to define internal spaces 29 within the building construction 11. The internal spaces 29 equate to rooms within a typical building construction. The fall arrest system 10 according to the first embodiment comprises a fall arrest barrier 30 positioned on the upper side of the ceiling joists 23. With this 10 arrangement, the barrier 30 rests on the ceiling joists 23 and any supporting beams 26, as shown in Figures 3 and 4. The barrier 30 is defined by barrier material which in this embodiment comprises high density polyethylene (HDPE) fabric configured as mesh netting. It is believed that a suitable barrier material would comprise HDPE mesh netting of knitted 15 construction which is known and used as shade cloth. A particular advantage of HDPE mesh netting of knitted construction is that is can be perforated to allow penetrations (such as cabling and conduits) without adversely affecting the structural integrity of the netting. A suitable HDPE mesh netting is knitted at 400gms/Mi 2 20 The barrier 30 in this embodiment comprises a plurality of barrier sheet sections each configured as a strip 31. Each strip 31 has opposed longitudinal edge sections 32. In this embodiment, the strips 31 have a width of 3.8m, although other widths may also be used. The strips 31 in this embodiment are oriented to extend cross-wise over the 25 ceiling joists 23. In other words, each strip 31 is installed such that its longitudinal extent it is substantially normal to the direction in which the ceiling joists 23 extend. In other installation arrangements, the strips 31 may extend lengthwise along the ceiling joists 23.

-11 Each strip 31 terminates inwardly of the wall plates 21 between which it extends and rests on the intervening ceiling joists 23. The strip 31 are anchored at intervals to the ceiling joists 23, The strips 31 are positioned in side-by-side relation to form the barrier 30, with 5 adjacent strips 31 being connected together at junctions 33 to provide integrity to the barrier 30. In the arrangement shown, adjacent strips 31 are disposed in overlapping relation to provide the junctions 33, as depicted in Figures 5 and 14, with overlapping edge sections 32a, 32b being connected together at intervals. The strips 31 are anchored to the ceiling joists 23, and optionally any intervening 10 supporting beams, at anchoring points which are identified by reference numeral 34 in Figures 1, 5 and 6. The anchoring points 34 are at spaced intervals, which may typically be about 600mm intervals. Typically, the strips 31 are fixed to the ceiling joists 23 inwardly of the wall plates 21; for example, at a distance of about 10 to 15cm inwardly of the wall plate 21, 15 although this can of course vary. Each strips 31 is fixed to respective ceiling joists 23 at the opposed end sections of the strip. The interior region 30a of the barrier 30 defined by the strips 31 is not fixed to the ceiling joists 23 or other roof frame elements, apart from along the junctions 33 20 between adjacent strips 31. In this embodiment where the barrier 30 comprises the strips 31 positioned in side-by-side relation to form the barrier 30, with adjacent strips 31 being connected together to provide integrity to the barrier, the outermost strips 31a would be fixed at intervals along their outer longitudinal marginal edge sections 32a to respective ceiling joists 23. The intervening strips 25 31b disposed between the two outermost strips 31a would be connected to the respective ceiling joists 23 only along their outer longitudinal marginal edge sections 32b; that is, at the junctions 33 with adjacent strips. The connection between adjacent strips 31 entails the overlapping edge sections 32 being connected together by fixing to the respective ceiling joists at intervals along the 30 junction 33.

-12 This manner of fixings allows to inner region 30a of the barrier 30 to move relative to the ceiling joists 23 to progressively arrest a fall. The strips 31 are preferably laid on the ceiling joists 23 in a relatively loose condition (rather than in a taut condition) in order to provide sufficient surplus 5 material to allow the barrier 30 to slide somewhat with respect to the ceiling joints, thereby facilitating progressive retardation to a fall. The barrier 30 is attached in position by anchoring elements 35. The anchoring elements serve to fix the barrier 30 to the ceiling joists 23 at anchoring points corresponding to the location of the anchoring elements 35. 10 The anchoring elements 35 are typically removable for re-use. The strips 31 may incorporate longitudinal bands 36 to provide a visual guide to facilitate placement of the anchoring elements 35. The bands 36 may be spaced at about 600mm intervals. Each anchoring element 35 comprises a body 37 presenting a broad lower face 15 39 for location against the barrier sheet 31, the face being configured for gripping engagement with the sheet. In particular, the face 39 incorporates a formation' 41 which presents a plurality of spikes or teeth 43 for gripping the barrier sheet 31. The anchoring element 35 is adapted to be fastened to the respective ceiling joist 23 to clamp the barrier sheet 31between the lower face 39 and the upper side of 20 the ceiling joist. The anchoring element 35 is adapted to be attached to the ceiling joist 23 by at least one fastener passing through the body 37. In the arrangement shown, the body 37 incorporate two holes 45 to receive fasteners 46 such as Tek screws. The body 37 has an upper side 47 incorporating a boss 49 about each hole 45. 25 The boss 49 is configured to provide a seat 51 for the head 46a of the fastener 46 received in the hole 45. The boss 49 is of a thickness to accommodate wear of the seat 51 during multiples uses of the anchoring element 35. By way of explanation, the seat 51 formed by the boss 49 wears each time it is engaged during use by the head of a fastener 46. Thus, the seat 51 progressively wears - 13 away during the multiple uses. The boss 49 is of a thickness to accommodate this progressive wear of the seat 51 and thereby allow a certain number of multiple uses. In this way, the boss 49 is sacrificial in nature. In Figure 15, an installer 60 is depicted installing the fall arrest system 10 5 according to the first embodiment installed in a building 11 under construction. In particular, there is shown the manner in which the junction 33 is formed between two adjacent strips which are identified by reference numerals 31c and 31d respectively. In the arrangement shown, strip 31c is installed and then strip 31d is laid on top of strip 31c, with the longitudinal edge section 32d of strip 31d in 10 alignment with, and overlaying, the longitudinal edge section 32c of strip 31c. Anchoring elements 35 are then installed along the aligned longitudinal edge sections 32c, 32d at locations corresponding to the underlying ceiling joists 23. The upper strip 31d is then folded over the junction 33 so as to lie adjacent the strip 31c, as depicted in Figure 14. The next strip (not shown) can then be 15 installed in position adjacent strip 31d in a similar manner. In this embodiment, the strips 31 are successively dispensed from a roll 61 of barrier sheet material 63 rotatably supported on a portable frame structure 65 positioned at a convenient location on the site of the building 11 under construction, as depicted in Figure 16. Each strip 31 is drawn from the roll 61 and 20 passed (while being drawn from the roll) into position across the ceiling joist 23. The respective strip 31 can then be cut from the barrier sheet material 63 remaining on the roll 61 once it is in position across the ceiling joists 23. Once the barrier 30 has been installed in position, it provides a safety barrier which can arrest the fall of a person or piece of equipment from the roof space 27 25 above. In this way, the safety barrier prevents or at least retards the fall prior to the falling person or equipment hitting the floor below or any personnel working within the internal space 29. Depending on the mass of the falling person or equipment, the barrier 30, or at least some strips 31 thereof, may well stretch as it retards the fall, but nevertheless will typically maintain its integrating in order to 30 provide an effective safety net. It may be that, in certain circumstances, one or more of the anchoring elements 35 detach from the ceiling joists 23, but it is -14 expected that the barrier would nevertheless still provide an effective safety net to at least retard the fall. The mesh netting can be perforated once installed to allow penetrations (such as cabling and conduits) to pass therethrough if required without adversely affecting 5 the structural integrity of the barrier 30. In a variation to the first embodiment, the strips 31 may be laid along the ceiling joists 23 and over any supporting beams 26 which they might encounter. The strips 31 may extend between, but terminate at end edges inwardly of the wall plates. Alternatively, the strips 31 may extend to, and be anchored to, the 10 wall plates 21. In the embodiment shown in Figure 17 , each strip 31 incorporates reinforcement 71 to enhance its robustness for arresting a fall. The reinforcement 71 comprises one or more reinforcement bands 73 integral with the barrier material and extending along the length of the strip. The reinforcement band(s) 73 can be 15 provided to the strip 31 in any appropriate way, such as by weaving it into the strip (to thereby be formed integrally with the strip), or formed separately as a web which is bonded, sewn or otherwise affixed to the strip. With such an arrangement, each strip 31 would typically be anchored to ceiling joists 23 or other frame members through the reinforcement band(s) 73. This may assist in 20 achieving a more robust installation for certain applications. By way of example, where reinforcement bands 73 are knitted integrally with the mesh netting, the mesh netting may be knitted at 400gms/m 2 and the reinforcement bands 73 knitted at 450gms/m 2 . The reinforcement bands 73 would preferably be distinguishable visually from the remainder of the mesh 25 netting. Typically, this would be accomplished by colouring the reinforcement bands differently from the remainder of the mesh netting. In such an arrangement, the reinforcement bands 73 may serve the function of the longitudinal bands 36 to provide a visual guide to facilitate placement of the anchoring elements 35, as described in relation to the previous embodiment.

-15 In a third embodiment, which is shown in Figures 18 and 19, the barrier 30 is attached to the underside of the ceiling joists 23. Typically, the barrier sheet 31 is draped between two opposed perimeter walls 13, and over any intervening internal walls 15, as illustrated in Figure 18, prior to 5 installation of the ceiling joists 23 and the roof framing 25. The sheet may also be draped over adjacent walls. The barrier 30 may comprise a unitary sheet draped over the entire perimeter of the building construction 11, or it may comprise a plurality of sheet sections 31 draped one adjacent another, preferably in overlapping relation. Typically, the 10 sheet sections are configured as strips, as was the case in earlier embodiments. Once the barrier 30 has been positioned between two opposed perimeter walls 13, and over any intervening internal walls 15, as illustrated in Figure 17, the ceiling joists 23 are installed. The ceiling joists 23 are installed in the conventional manner, bearing on the wall plates 21 of the particular walls on which they are 15 supported. In this way, the barrier sheet 31 is clamped between the ceiling joists 23 and the underlying wall plates. The barrier sheet 31 is also attached at intervals to the underside of the ceiling joists 23, as shown in Figure 18, by anchoring elements 35. When the building construction is at a stage where ceiling sheeting is to be 20 installed, the anchoring elements 35 are removed from the underside of the ceiling joists to allow for placement of ceiling sheets in position. The ceiling sheets can be place in position against the underside of the ceiling joists 23 with the barrier sheet 31 still in position. Alternatively, the barrier sheet 31 can be removed prior to placement of the ceiling 25 sheeting in position. The barrier sheet 31 can be simply cut away. Typically, this would be done using a knife or other appropriate cutting implement to cut the barrier sheet 31 adjacent the wall plates 21. In this way, the majority of the barrier sheet material can be removed, leaving only that portion clamped between wall plates 21 and the ceiling joists 23 bearing on the wall plates.

- 16 Referring to Figure 20 of the drawings, there is shown a fall arrest system 10 according to the fourth embodiment. The fall arrest system 10 according to the fourth embodiment is used with a building construction 11 in which the roof framing 25 comprises roof trusses 81 having bottom chords 83. The roof trusses 5 81 are supported on the perimeter walls 13, as is conventional practice with such a construction. Battens 85 are fixed to the underside of the bottom chords 83, and ceiling sheeting (not shown) is attached to the battens in known manner. In this embodiment the barrier sheet 31 is draped between two opposed perimeter walls 13, and over any intervening internal walls 15, as was the case with the third 10 embodiment, prior to installation of the roof trusses 81. Once the barrier sheet 31 has been positioned between two opposed perimeter walls 13, and over any intervening internal walls 15, the roof trusses 81 are installed. In this way, the barrier sheet 31 is clamped between the bottom chords 63 and the underlying walls. 15 The barrier sheet 31 is also attached at intervals to the underside of the bottom chords 83. In this embodiment, the barrier sheet 31 is clamped between the bottom chords 83 and the battens 85 as the latter are fixed in position. In the arrangement illustrated, the battens 85 comprise steel battens 87 having a central channel portion 88 and two lateral flange portions 89 which are fastened to the 20 bottom chords 83. With this arrangement, the barrier sheet 31 is clamped between the chords 83 and the lateral flange portions 89. The barrier sheet 31 can be removed prior to fixing of ceiling sheeting to the battens 85. Alternatively the barrier sheet 31 can remain in place, as its presence does not unduly impede installation of the ceiling sheeting. The benefit of 25 retaining the barrier sheet 31 in place is that it would provide an ongoing safety barrier preventing or arresting falls through the ceiling, even after completion of the building construction. From the foregoing, it is evident that the present embodiments each provide a simple yet highly effective fall arrest system below the roof spaces of buildings 30 under construction.

-17 It should be appreciated that the scope of the invention is not limited to the scope of the embodiments described. Throughout the specification and claims, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be 5 understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims (40)

1. A fall arrest system for a building under construction having frame members and an internal space within the building defined below the frame members, the fall arrest system comprising a barrier spanning the frame 5 members.

2. The fall arrest system according to claim I wherein the barrier comprises a single barrier sheet.

3. The fall arrest system according to claim 1 wherein the barrier comprises a plurality of barrier sheets cooperating to provide the barrier. 10

4. The fall arrest system according to claim 1, 2 or 3 wherein the barrier is positioned above the frame members.

5. The fall arrest system according to claim 1, 2 or 3 wherein the barrier is positioned below the frame members.

6. The fall arrest system according to claim 1, 2 or 3 wherein the barrier is 15 arranged to be disposed above some frame members and below other frame members.

7. The fall arrest system according to any one of the preceding claims wherein the barrier is fixed to the frame members at its marginal edge portions, with the interior region of the barrier being fixed along junctions 20 between adjacent strips which cooperate to form the barrier.

8. The fall arrest system according to any one of the preceding claims wherein the frame members form part of a frame construction and the barrier is attached to the frame construction

9. The fall arrest system according to any one of the preceding claims 25 wherein the frame members comprise ceiling joists.

10.The fall arrest system according to any one of the preceding claims wherein the barrier comprise nettings. - 19

11. The fall arrest system according to claim 10 wherein netting is of a knitted construction.

12.The fall arrest system according to any one of the preceding claims wherein the barrier sheet is in strip form. 5

13.The fall arrest system according to claim 12 wherein the barrier comprises a plurality of the strips and the strips are positioned in side-by-side relation to provide the safety barrier.

14.The fall arrest system according to claim 13 wherein adjacent strips are interconnected. 10

15.The fall arrest system according to claim 14 wherein adjacent strips are in overlapping arrangement, with overlapping sections connected together.

16.The fall arrest system according to claim 15 wherein the overlapping sections are connected together in spaced apart relation along the length of the overlap and the overlapping strips are fixed to the frame elements. 15

17.The fall arrest system according to any one of the preceding claims further comprising anchoring elements for fixing the barrier in position.

18.The fall arrest system according to claim 17 wherein the anchoring elements each comprise a body presenting a broad face for location against the barrier, the face being configured for gripping engagement with 20 the barrier.

19.The fall arrest system according to claim 18 wherein each anchoring element is adapted to be fastened to a respective surface to clamp the barrier between the broad face and the surface to which the anchoring element is attached. 25 20.The fall arrest system according to claim 19 wherein each anchoring element is adapted to be attached to the surface by at least one fastener passing through the body.

- 20

21.The fall arrest system according to claim 18, 19 or 20 wherein the broad face incorporates a formation which presents a plurality of spikes or teeth for gripping the barrier.

22.An anchoring element for a fall arrest system according to any one of the 5 preceding claims.

23.An anchoring element comprising a body presenting a broad face for location against a barrier for fixing the barrier to a frame element of a building under construction to provide a fall arrest system, the face being configured for gripping engagement with the barrier. 10

24.A fall arrest system for an internal space within a building under construction, the internal space being defined below frame members, the fall arrest system comprising a barrier sheet spanning the frame members.

25.A building construction incorporating a fall arrest system according to any one of the preceding claims. 15

26.A method of installing a fall arrest system according to a first or second aspect of the invention.

27.A method of installing a fall arrest system in a building under construction comprising a plurality of frame members, the method comprising the following steps: providing a strip of barrier material; and installing the strip 20 on the frame members to provide at least part of a fall arrest barrier.

28.A method of installing a fall arrest system in a building under construction comprising a plurality of frame members extending in a first direction, the method comprising the following steps: providing a strip of barrier material; and installing the strip across the frame members to provide at least part of 25 a fall arrest barrier.

29.A method of installing a fall arrest system in a building under construction comprising a plurality of frame members extending in a first direction, the method comprising the following steps: providing a strip of barrier; and -21 installing the strip lengthwise along the frame members to provide at least part of a fall arrest barrier.

30.The method according to any one of claims 26 to 29 wherein the strip is installed across the frame members such that its longitudinal extent is in a 5 second direction substantially normal to the first direction.

31.The method according to any one of claims 26 to 30 wherein the step of installing the strip on the frame members to provide a fall arrest barrier includes anchoring the strip in position in the building.

32.The method according to any one of claims 27 to 31 further comprising 10 installing one or more further strip across the frame members, wherein the strips cooperate to define the fall arrest barrier.

33.The method according to claim 32 wherein the strips are installed in side by-side relation and wherein the method further includes interconnecting adjacent strips. 15

34.The method according to claim 33 wherein adjacent strips are in overlapping arrangement, with the overlapping sections connected together.

35. The method according to any one of claims 27 to 31 wherein the strips of barrier material are obtained from a roll of barrier material and wherein the 20 method further comprises positioning the roll of barrier material at a nearby location, drawing a strip of barrier material from the roll and passing the strip as it is being drawn from the roll into position over the frame members.

36.A method of installing a fall arrest system in a building under construction having two sections, the method comprising draping a sheet of barrier 25 material over the two sections to extend therebetween, installing fame members above the sheet of barrier material draped between the sections, and attaching the sheet of barrier material to the underside of the frame members. -22

37.A fall arrest system for a building under construction having frame members, the fall arrest system comprising a sheet of barrier material disposed above but positioned on the frame members.

38.A fall arrest system for a building under construction having frame 5 members, the fall arrest system comprising a sheet of barrier material attached to the underside of the frame members.

39.A fall arrest system substantially as herein described with reference to the accompanying drawings.

40.A method of installing a fall arrest system in a building under construction 10 substantially as herein described.