Through glass patch fittings supporting cantilevered structural glass panels
In many architectural contexts, the balustrade is required to maximise light, space and transparency.
In many architectural contexts, the balustrade is required to maximise light, space and transparency. On a feature staircase, the priority may be to maximise the impact of the tread and stringer design. In void edge applications, the sense of openness, or the highlighting of other architectural features may be required. When less is more, a fully cantilevered solution such as F8 is often the best choice.
Modern glass manufacturing methods permit curves and a wide variety of shapes, as well as relatively long spans. As the photographs and renderings show, dramatic architectural statements can be made in either format. Because the F8 style avoids the use of stanchions entirely, the eye is drawn to the patch fittings that effect the structural fixing and support the handrail. The selection of Arden system PF10/PF12 stainless steel patch fittings significantly enhances the appearance of the F8 design with clean geometrical details.
The F8 cantilevered glass balustrade design relies on the strength of structural glass and proprietary heavy-duty stainless steel patch-fittings to transfer loads from handrails to structural floors or staircase components. Cantilevered glass based on the use of patch fittings typically forms the cantilever by a series of upper and lower patch fittings, fixed to the stringer face or floor edge. The cantilever effect is one of a simple lever calculation where the load applied to the glass is resisted by the bottom and top patch fittings that act in compression whilst its partner is acting in tension.
The engineering therefore needs to consider the following:
a) the load applied to the glass (varies according to the situation - see AS1170.1)
b) the height of the glass (effectively setting the length of the "lever")
c) the horizontal spacing of the fittings (determines how each series shares the load)
d) the vertical spacing of the fittings (determines the amount of compression and tension that is applied to the patch fittings)
e) the specifications of the glass, which determines the size and thickness required to handle the loads applied and then resisted by the patch fittings
Consideration of all of these factors then sets the glass specification and the number and type of patch fittings including pull-out strengths required of the fittings to the structure.
Arden Architectural 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 this design element, the table below details compliance with relevant codes and standards.
||The Building Code of Australia
|AS NZS 1170.1-2002
||Structural Design Actions – Permanent, imposed and other actions
||Glass in Buildings. Selection and installation
|AS NZS 1554.1-2004
||Structural steel welding - Welding of steel structures
||Welding stainless steels for structural purposes
|AS NZS 4586-2004
||Slip resistance classification of new pedestrian surface materials
||Design for access and mobility
||Fixed platforms, walkways, stairways and ladders. Design,
construction and installation