Award for Excellence 2017, Tension & Air Supported Structures less than 250sqm

Imagine a Sumatran house, with 2 roofs joining along a centre line.. Now take both ends of the structure and pull them in opposite directions... Now all we need to do is work out a way to make it out of PVC membrane. 

This project required a highly intricate and complex waterproof membrane structure to function as a new eating area. 105m2 of membrane fully self supporting with limited moment being transferred into the supporting podium slab. High quality 2Pac paint finish to all steelwork.

6 weeks to deliver from start to finish.

The client Requested a unique looking structure to closely mirror the buildings of the Tigers natural homeland. The brief given to our team was to come up with a waterproof membrane with some preliminary architectural sketches, to closely resemble Traditional Sumatran houses. This was to be used as a waterproof dining area as part of a large re-development of an iconic theme park feature area.

The shape of this structure meant was highly complicated. With few parallel lines to aid in ease of design, fabrication and installation, the entirety of the structure was challenging. Every steel member was different. The entire structure was A-symmetrical. Key difficulties are as follows.

  1. A-symmetrical shape of structure, basically a parallelogram without the parallel part. Column centres also varied along the length of the structure making setout challenging.
  2. End Gable pitches lean out at a 45 degree angle, Triangle end frames are equilateral but pivoting along the non parallel ends of the structure. meaning that bracing steelwork (Ridge beam is also angled out of parallel to the edge beams)
  3. Valley beam required to maintain a completely waterproof function whilst also holding the membrane into shape. We worked out a way to allow this to happen by fixing through the beam with sailtrack and fabricating the membrane in a way that would allow the top skin to remain fully sealed, meaning no weather strips were required to keep the length of the Valley waterproof. 
  4. The entire membrane is fitted to the steelwork with Bolt/Rope sail track, all edges are tensioned to home position with sailtrack finishing perfectly at the cleat. 
  5. Gutters were required to be integrated into the design to allow for a neat finish. 
  6. A custom rain head was designed to fit perfectly to steelwork, note this also had to be 100% custom made, A-symmetrical in design and fabrication.
  7. 119 individual pages of steel workshop drawings, making this a record amount of fabrication plans required for such a small structure. This does not include engineering plans, diagrams, sketches and fabric patterning plans.
  8. We had 6 weeks from official approval to proceed, To complete the following; Engineering, Design, Steel fabrication, membrane Fabrication, Steel coating in a custom grade 2 PAC system, Installation, Gutters, downpipes. 
  9. Loads being transferred into slab had to be minimal, the structure was designed to impart no moment into slab based on theoretical pinned connections at base, then this was cross checked to calculate actual loads that would be imparted to ensure these met with the slab engineers tolerances.
  10. Site access was extremely tight for installation particularly on the front and rear ends. These could not be accessed by scaffold from deck level, so Boom lifts had to be used with millimeter precision to access the edge of the structure. 
  11. Membrane installation was also a huge challenge, ensuring that the skin was tensioned evenly on a very odd shape where all edges are to finish hard up to the steelwork was fun to say the least. Particularly when we had to maintain a mitered connection between the sail track to ensure a neat appearance. This meant the approach was very time consuming and had to be thought out.
  12. So many more intricacies to get into one description... This was a very challenging project but highly rewarding also.

The client was absolutely over the moon with the end result, the architect couldn't believe how light the membrane makes the area feel whilst still delivering on the design intent. Natural light under the structure is inviting and not requiring artificial lighting during the day.