P2

Feature PFC stringer

Design

Structural steel members are surprisingly graceful and have a beauty all of their own. That is, they do if you get the design right, and we believe we have done just that with the P2 Feature PFC design. In the P1 design, the PFC members get the structural work done ‘behind the scenes’ and permitting a wide variety of cladding methods. In contrast, the P2 represents a very specific design, with interlocking structural steel members being the main structural feature.

This brings a source of tension into the design, as the relatively open and sparse profile contrasts with the weight and impact of the structural steel. If pure heavy metal isn’t your style, the P2 can be modified to present a more refined appearance by the installation of timber panels within each member. Figure (5) illustrates that this can accent the natural geometric lines of the staircase with timber grain and shadow line details.

Technical

PFC (parallel flanged channels) are a standard structural steel component, similar to more standard items such as universal beams and columns. Hot formed sections such as PFC’s offer an “off the shelf” structural solution to a number of application with staircases being one of those applications that are particularly apt.

In staircases, the size of the PFC is determined by its structural duties and varies according to application from 300PFC (300x90) down to 185PFC (185x70).

The major advantages of the use of PFC’s as stringers are:

a) Engineered structural properties including torsional and lateral strength

b) Ease in fabrication in that it is straight and provided one face for the simple welding of steel tread cleats, steel tread supports, folded steel tread and riser assemblies and the like.

c) Balustrade application to a PFC typically takes advantage of the flat top of the pfc (The flange) although other, (typically more complicated) solutions are possible to the open channel side of the PFC

Whilst PFC stringers offer a simple engineering solution for stringer in most applications, thought needs to be applied to how this may affect the styles available for a balustrade solution

Compliance

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.

Code	Title	Applicability
BCA	The Building Code of Australia	Full compliance
AS NZS 1170.1-2002	Structural Design Actions – Permanent, imposed and other actions	Full compliance
AS 1288-2006	Glass in Buildings. Selection and installation	Not applicable
AS NZS 1554.1-2004	Structural steel welding - Welding of steel structures	Full compliance
AS 1554.6-1994	Welding stainless steels for structural purposes	Full compliance
AS NZS 4586-2004	Slip resistance classification of new pedestrian surface materials	Full compliance
AS 1428.1-2001	Design for access and mobility	Full compliance
AS 1657-1992	Fixed platforms, walkways, stairways and ladders. Design, construction and installation	Full compliance