ASHGRID™ Spacer Support System ™- SECURE by DESIGN
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Uniclass EPIC L557:P41 E191:X412 CI/SfB (49) Xh2 November 2012 ASHGRID™ spacer support system ™- SECURE BY DESIGN www.ashandlacy.com Contents Introduction 2 Firewalls 9 Installation 3 Thermal requirements / Pitched roofs 4 loading out 11 Rooflights Standing (ADL1&2) 5 seam roofing system 12 Vertical sheeting 6 Case study 13 Horizontal Envelope sheeting 7 solution 14 ™ - SECURE BY DESIGN No sway brackets 1 Introduction As part of our programme of continuous innovation, Ash & Lacy introduce the new high performance Ashgrid bar and brackets incorporating the unique Safe-Loc™ feature (patent applied for). Designed to meet the ever-increasing demands from Building Regulations whilst at the same time making installation more efficient and safer for contractors on site. All spacer support systems are at risk during the installation stage when they are not restrained by the sheeting and are subjected to forces from foot traffic, temporary loading and high winds. Accurate, close fitting and reliable bar An ongoing programme of research and connections are also required to ensure development into the system, the first the stability of any spacer support system engineered spacer support system in the during construction with some systems UK, has ensured Ashgrid has remained Deeper even having to rely upon screw fixings to an optimum solution for a wide range of bar ribs prevent their bars from separating**. roofing applications. The new Ashgrid Safe-Loc™ spacer support system addresses these issues I through a combination of innovative New Safe-Loc™ spigots – fast, design features which improve system secure and safe bar joints stability, safety and ease of construction, I No need for bar end fixings – reducing installation time and costs when saving time and cost compared with other spacer support systems. I Raises the standards for spacer support systems Stronger The enhanced AG40 spigot design with bracket its new innovative Safe-Loc™ feature I Maximum spigot efficiency is (patent applied for) provides stability and always achieved and a consistent peace of mind at the click of a tab. This module maintained prevents the Ashgrid bars from separating during the installation process I Allows continuous load transfer ensuring safe, precise gauging as well as throughout the bar run quicker installation. The AG40 bar is I widely acknowledged to be of superior New high performance brackets quality and is produced to exact with deeper ribs for improved engineering tolerances. With the spigots structural performance pushed home in one quick and easy I No requirement for anti-sway action, the Safe-Loc™ tab engages, brackets below 250mm* providing the added security benefit of an construction depth automatic inter-lock between the bars every time. Once engaged the bar ends I Quick, easy and safe insertion of cannot be accidentally or unintentionally brackets from the side or from the separated ensuring the system remains bar ends stable and secure during the critical installation stages. Nevertheless, the I Brackets can be easily joints can be ‘unlocked’ if the need arises. repositioned if required The enhanced bracket design with deep I Deep ribbed bar, ensuring ribs further increases the performance of optimum fixing efficiency for the the Ashgrid system, removing the need top sheet for anti-sway brackets at construction I depths below 250mm*. Ashgrid Safe- High fixing torque and increased Loc provides more benefits to the installer pull-out strengths achieved with fewer components, faster installation I Full range of roof, wall cladding times and reduced system costs. and firewall solutions The time proven ‘twist-lock’ feature of the I Comprehensive and friendly Ashgrid brackets still remains as popular technical backup with nationwide today as always. With its easy slide and distribution twist action from the bar ends, or engage and twist to fit at any point along the bar. ** In line forces can be transmitted through the joint The fitting of the brackets is simplicity itself without the need for screw fasteners. and the quickest in the marketplace, easy from first to last with a minimum of force * For exceptional site loading conditions and for required, reducing the risk of cut hands. heights above 250mm advice on performance should be sought from the Ash & Lacy Technical The brackets are also just as easy to Department. disengage and re-position if necessary. 2 Installation With the advent of ADL1& 2 of the Building Regulations Construction depths up to and including and the requirement for deeper thermal cavities within 250mm built-up systems, it has become increasingly important that careful consideration be given to the safety and All spacer support systems will be exposed to in-line security of the installers and the spacer support sway forces during their installation. To counter this, the system, in particular during the construction phases. stability of AG40 has been further enhanced through improvements in bracket design and the introduction A roofing system is at its greatest risk during the of the Safe-Loc™ spigots. These designed-in features installation stage when it is not restrained by the top perform each and every time, providing peace of mind sheeting and is subjected to loading from foot traffic, without reliance on extra, time consuming bar-end temporary loading and heavy sheet packs. This fixings and anti-sway brackets. combined with drag forces from high winds tends to compound these problems further. For cavity depths up to and including 250mm no additional sway control measures need to be With construction depths increasingly exceeding employed on the new Ashgrid AG40. 200mm and with the ongoing need to improve installation efficiency and system performance, For exceptional site loading conditions and for heights Ashgrid AG40 has been further enhanced to satisfy above 250mm advice on performance should be these increasingly demanding requirements. sought from the Ash & Lacy Technical Department. Choice of installation methods to suit personal preference and site conditions Method 1 1 2 3 1. Lay bar on roof deck and offer the 2. Tilt and rotate bracket backwards 3. Twist bracket and snap into small flange of the bracket to the at desired fixing position. position at 90° to bar. small flange of the bar. Method 2 1 2 3 1. Offer the bracket to the bar at an 2. Slide brackets along the bar to 3. Snap each bracket upright to lock angle from the non-spigot end. the desired fixing positions. into position at 90° to the bar. Brackets may be repositioned by reversing this action and sliding along the bar as in steps 1 & 2. 4. Making certain there is a bracket 5. Engage the open end of the bar 6. Continue as above for quick, safe within 100mm of a spigot end, onto the Safe-Loc™ spigot and and secure installation. install additional brackets to push firmly until the tab clicks into Brackets should be fixed to the roof match the liner module up to 1m position. To release, simply deck using two Ashfix LS25 centres maximum. (Bracket depress the tab with a sharp fasteners inclined and ensuring that centres may need to be reduced object such as a screwdriver. brackets do not twist in the bar. in areas of high wind suction or heavy snow loading). 3 Pitched roofs Bend straps over AG40 and 50 x 1.0 Galvanised steel screw fixings into bracket strap (or similar) With roof constructions ever increasing in depth The steel strap should be bent over and around the there is a tendency for the support system to rotate AG40 bar and fixed to the small flange using two screw down the slope by the action of the roof loading. To fixings. prevent this, the ridge brackets must be fully tied To eliminate any out of balance forces it may be together as illustrated. Screw fixing the end and prudent to sheet both slopes in unison, gradually side laps of the roof sheet ensures continuity. This working up to the ridge detail. enables each roof slope to act as a stress plate hanging from the fixed ridge detail and reduces any downslope movement. Note It is preferable that the Ashgrid brackets either side of the ridge are installed in line. 4 Rooflights (ADL1&2) 3m Ashgrid Bar or LAY RIGHT TO LEFT 2m Ashgrid Bar Rooflight 1.2m max Ashgrid bracket (100mm from end) A rooflight build-up conforming with the In areas of high wind suction loads or heavy drifting requirements of ADL 1& 2 requires the Ashgrid snow the bar is further reinforced with a top hat 40 brackets to be installed either side of the module, section. This sits tightly over the Ashgrid AG40 for a resulting in the Ashgrid bar spanning 1200mm as distance of 1500mm over this bay and is screwed to shown above. To maintain the structural adequacy the bar at 500mm centres along its length. of the bar, we would recommend either a 2m or 3m For further information, please contact our technical length of bar positively fixed with the new department. Safe-Loc™ feature to provide the continuity required over the central rooflight zone. LOAD SPAN TABLE FOR ASHGRID AG40 ROOFLIGHT DETAIL Notes Bracket Purlin Centres (m) Direction I centres All loads are working loads of 1.0 1.2 1.4 1.6 1.8 2.0 along bar loading I Steel based on Z35 material (m) Loading in kN/m2 I Download deflection = span/200 Download 2.23 1.86 1.59 1.39 1.24 1.12 I Figures limited to a bar/bracket 1.0 Uplift 2.55 2.13 1.82 1.59 1.42 1.28 connection load of 3kN I Pull-out of screws into purlin Download 1.84 1.54 1.32 1.15 1.02 0.92 AG40 assumed to be 3kN 1.1 BAR Uplift 2.11 1.76 1.51 1.32 1.17 1.05 I Ultimate bending stress is based on a load factor of 1.6 for Download 1.55 1.29 1.11 0.97 0.86 0.77 download and 1.4 for uplift 1.2 Uplift 1.77 1.48 1.26 1.11 0.98 0.89 Download 3.00 2.50 2.14 1.88 1.67 1.50 1.0 Uplift 3.00 2.50 2.14 1.88 1.67 1.50 AG40 Download 2.73 2.27 1.95 1.70 1.52 1.36 BAR 1.1 WITH Uplift 2.73 2.27 1.95 1.70 1.52 1.36 TH40 Download 2.50 2.08 1.79 1.56 1.39 1.25 1.2 Uplift 2.50 2.08 1.79 1.56 1.39 1.25 5 Vertical sheeting For bracket depths of up to 200mm the standard Ashgrid system may be used with brackets at 1m centres maximum with reduced centres in high wind suction zones if necessary.