Semi-framed steel and glass panel balustrade

Transcription

1 Semi-framed steel and glass panel balustrade design elements G2

2 Semi-framed steel and glass panel balustrade G2 design The G2 semi-frameless balustrade design is one of the most elegant balustrade formats in the Arden catalogue. Glass panels are surrounded by a full perimeter stainless or mild steel frame, with glazing channel top and bottom. Clear space between glass and frame is maintained laterally on each side. The frame and handrail is supported by stanchions (typically SHS or blade profile stainless / mild steel) interposed between each panel. The vertical frame members may be hard up again each side of the stanchion, or set-back by small off-stands (typically steel rod). The entire balustrade section may be capped with a handrail of any material and profile, and/or combined with an offset handrail. Finally, the semi-framed panels may be fixed to the treads / structural floor, fixed to a stringer such as a PFC, or face fixed to the stringer or treads. All implementations of the G2 tend to share a sense of luxury and even opulence. This is demonstrated by the some of the featured images, where crisp white stone, American Oak and built-in lights accentuate the effect. Even when the materials chosen are restricted to only stainless steel and glass, the interactions of geometry between the various components create a fine, intricate impression. Timber handrail with stainless steel ribbon plate support Corner stanchion Intermediate stanchions Line of stringer Level panel with stainless steel framing Connecting void edge balustrade omitted 1A 2

3 Floor to floor covered rise Clear space between handrails A 118. Clear space between handrail and glass panel frame 51 (50 min). Clear space between handrail and stanchion Upper floor void edge bulkhead EQ Figure 1. Glass panels semi-framed with stainless steel supported by floor fixed blade stanchions. 1A. Isometric overview of installation on U-shaped staircase. 1B. Front and side elevations. Balustrade panels are set out to achieve maximal coherence in terms of proportion and alignment. To achieve this, glass panels incorporating internal and external angles are applied. Care must be taken to ensure that enough space is nominated to allow a continuous line of handrail and balustrade as it transitions between different raking and level heights (typically ~900mm and ~1050mm respectively). Overall width of flights is determined by the desired traversable width of each flight, the required clear space around the handrail, stanchion and stringer details, as well as the space specified between flights. F indicated on dimensions denotes a nominal dimension that typically varies according to specific application, engineering requirements or client preferences. EQ 1050 (1000 min) Upper floor level handrail height Upper structural floor Semi-framed steel and glass panel balustrade G2 PFC stringer with fascia board Level panel Transitional panel Balustrade height at landing Raking panel Lower floor structure Overall width of flight 1B design elements 3

4 18 8 Semi-framed steel and glass panel balustrade G2 technical In this balustrade style, the glass component is infill glass with continuous support on the top and bottom edges. The continuous support of the glass (as opposed to patch fittings, being point loads) allows the specification of the laminated glass as infill glass, although toughened and toughened laminate could also be used. Arden suggests standard methods for approaching both the glazing channel frames and the blade stanchion supports. Some variation in the specific glazing profile and stanchion dimensions may be made for aesthetic or engineering considerations, depending on the specific properties of each project. Handrail fixing is always offset from the stanchion, either vertically or horizontally. Handrail profile style may be selected from Arden technical document A.4 Handrail profiles or a custom profile may be specified. 1C. Detail of semi-framed glass panel with stainless steel supported by blade stanchions. As the diagram shows, the height of handrail and blade stanchion can be specified at a nominal height below the top line of the balustrade frame. The stainless steel frame incorporates a glazing channel U section top and bottom, with only a minimal width for the vertical sections. We consider a significant gap between the glass and panel sides (nominal 55mm in the illustration) helps create a highly satisfactory detail between panels. Another possible variation to the G2 style is use full height stanchions, with handrail directly positioned above the panels, which has the advantage of increasing the traversable width of the flight. 1C Toughened safety glass panel (8-10mm typical thickness) Timber dowell handrail Stainless steel support ribbon Blade stanchion J J Light gauge vertical frame supports 6mm round connections to stanchion J-J Glass framed top and bottom by 18mm square C-channel 4

5 2A Full-height semi-framed panel (forms section of upper floor balustrade) Full height suspended 50.8SHS stainless steel stanchions Custom timber and stainless steel layered handrail Zig-zag plate stainless steel stringer Treads with non-slip strips B K Full height semi-framed panels on opposite site of stair C D G H Raking semi-framed glass panel 50.8 SHS stainless steel stanchions Figure 2. Glass panels semi-framed with stainless steel supported by face-fixed SHS stanchions. 2A. Isometric overview of installation on a straight flight with zigzag stringer and connections to upper floor balustrade. 2B. Side elevation. In this illustrative example, the RHS (near side) balustrade is comprised of standard raking panels, with the LHS (far side) balustrade panels extending to the upper floor balcony, creating a virtual internal glass wall. In this variant of the G2, the handrail is supported by custom angled rod connections from the stanchions. Semi-framed steel and glass panel balustrade G2 4 Raking semi-framed panel 2B B Zig-zag plate stainless steel stringer F indicated on dimensions denotes a nominal dimension that typically varies according to specific application, engineering requirements or client preferences. 5 design elements 5

6 81 10 Semi-framed steel and glass panel balustrade G2 2C Toughened safety glass (typically 8-12mm) or laminated safety glass (typically ) 2C. Detail of panel-to-stanchion fixing at a terminating stanchion illustrating the profile of the G2 installed using 50.8s SHS stainless steel stanchions. A slightly finer nominal margin of 23mm is allowed between the side of the glass panel and the vertical panel section, to balance the wider profile presented by the SHS stanchion. 2D. Front elevation. The use of facefixed stanchions with the G2 can slightly increase the clear traversable space on the flight. 2E. Plan view. In this example, stanchions and divisions between panels are located centre-of-tread. Stanchions are face fixed and also attached to the upper floor balustrade (excluded from diagram). 50mm clear space is maintained between the side of stanchion and the inner face of the handrail Connection between panel vertical section and stanchion 2D Clear space between handrail Line of stainless plate steel stringer Line of handrail Line of inner face of stanchions Semi-framed glass panels in-line with, and occluded by stanchions Vertical downturned section of stainless steel handrail plate F indicated on dimensions denotes a nominal dimension that typically varies according to specific application, engineering requirements or client preferences. 6

7 E Clear space betwen handrails Handrail supports from stanchions Extra-wide handrail profile. Note the example shown is a domestic installation and is not compliant. E 65 clear space between glass face and handrail 50 clear space between handrail and stanchion face (50 min) Treads with non-slip strips Semi-framed steel and glass panel balustrade G2 design elements 7

8 10 Semi-framed steel and glass panel balustrade G2 2F. Lower detail of stanchion showing detail of bottom raking corners of panels and connection to stringer. Note that the light gauge connection in this particular diagram is suitable for situations where the raking balustrade has a structural connection to the upper form balustrade. Where the balustrade is supported by the stringer alone, the fixing to stringer will vary. F indicated on dimensions denotes a nominal dimension that typically varies according to specific application, engineering requirements or client preferences. Treads with inset non-slip strips Plate stainless steel zig-zag stringer Light gauge fixing to stringer (heaver grade fixings required when stanchions are not fixed to upper balustrade 68 aligned overhang of semi-framed panels Stainless steel rod connections between stanchion and glass frame 2F 8

9 20 2G 2H 20 infill glass panels 6 10 B B Glazing channel C-sections top and bottom of panel Welded connection with raking handrail plate 10mm inset of glass into glazing channel Right angle handrail support Laminated or toughened glass panel Stainless steel rod connections between stanchion and glass frame 50mm clearance between stanchion and handrail 30mm clearance between stanchion and stringer This table shows the recommended maximum glass span (mm) depending on design load. Annealed laminated safety glass (mm) Toughened monolithic safety glass (mm) 2G. Detail of intermediate stanchion connection of G2 panels. The right angle handrail support ensures that the staircase complies with AS (disability and access). The lines of glass, stainless steel and timber components are judged carefully to present a highly effective detail at the visual connection detail between handrail, stanchion, frame and glass. 2H. Plan detail of stanchion, handrail and semi-framed panel layout. 50mm clear space is maintained between the side of stanchion and the inner face of the handrail. The 30mm stand-off of the face fixed stanchion may be varied to suit installation requirements. The dimensions shown are typical for a domestic installation. The gauge of members and connections would be generally be increased for a commercial project to meet design load requirements. Toughened laminated safety glass (mm) Design load Domestic/Residential Offices/Commercial stairs Retail/Restaurant C5 high loads Special glass engineering: designed as required Semi-framed steel and glass panel balustrade G2 Notes 1. These tables are to be used as a general design guide only. 2. Individual project requirements will dictate final glass specification and thickness. 3. All spans nominated are indicative of normal internal conditions. In some exposed situations, wind loads may exceed design load and thicker glass or smaller spans may be required. design elements 9

10 Semi-framed steel and glass panel balustrade G2 2I. Isometric detail of stanchion and handrail connection location. 2J. Isometric detail of stanchion and stringer connection location. design standards for glass panels Glass balustrade panels must satisfy engineering requirements as specified in AS1288, and the Arden balustrade styles shown here are defined and specified with regard to the relevant design standards. Of particular importance in the initial design stage, it is critical to maintain an awareness of the designation of glass panels as structural or infill, and the classification of handrail as loadsupporting, non-load-supporting, or interlinking. Combined with other considerations (e.g. whether or not mechanical point-fixings are specified, span is cantilevered or supported on both sides), this determines the grade of glass (e.g. laminated annealed, toughened safety, laminated toughened) and type of handrail that satisfies the code. As in other aspects of stair and balustrade design, Arden will advise with respect to the practicability of preliminary designs with respect to Australian standards. 2I glass balustrade styles Cantilevered structural. Glass panels supporting an interlinking handrail cantilever from an appropriate floor fixing. Fully framed. Glass panels are provided with four-edge support and are therefore rated as infill only. Two-edge clasp. Glass panels are supported on two opposite edges by clasp-style mechanical fixings. The bearing of point loads influence the required grade of glass. 2J Two-side patch-fitting. Glass panels are supported on two opposite sides by through-glass mechanical fixings. The bearing of point loads influence the required grade of glass. Stanchions may be located between, or at intermediate locations within, each panel span. Semi-framed lateral channel. Glass panels are fixed via proprietary or custom channel system on the bottom rail and underside of handrail. Hybrid. Glass panels are provided with a combination of the above methods so as to comply with safety requirements. 10

11 compliance Arden is a BSA licensed contractor for carpentry, joinery, glass, glazing and aluminium as well as structural metal fabrication and erection. Arden supplies a Form 16 (Licensed Contractor) on all projects. In design and construct contracts, a Form 15 (Design Engineer) certification is supplied upon request. For products and services incorporating the G2 system, this table shows compliance with relevant codes and standards. Key full compliance with the code not applicable to this element Code Title Applicability BCA The Building Code of Australia AS NZS Structural Design Actions Permanent, imposed and other actions AS Glass in Buildings. Selection and installation. AS NZS Structural steel welding - Welding of steel structures AS Welding stainless steels for structural purposes AS NZS Slip resistance classification of new pedestrian surface materials AS Design for access and mobility AS Fixed platforms, walkways, stairways & ladders. Design, construction and installation design note For all commercial applications, it is important that sufficient space for the stairwell cavity be allowed to satisfy Australian Standards and BCA requirements. About this document Intellectual property is copyright Archstairs Pty Ltd unless otherwise agreed in writing. All rights to the document are retained. Any use of the document by clients or third parties, unless specifically authorised by Archstairs Pty Ltd, are at their own risk and the user releases and indemnifies Archstairs Pty Ltd from and against all loss or damage arising from such use. Semi-framed steel and glass panel balustrade G2 The footprint is primarily driven by the floor to floor rise, as well as the staircase configuration chosen. However, stringer and balustrade style design may increase the amount of space required. Allowing too small a cavity can restrict the design options of the staircase. Also, points at where the staircase interacts with other structures are best addressed early in the design cycle. Consultation with Arden early on will help ensure that these design issues can be addressed in a cost-effective manner. design elements 11

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