Air NZ builds the Southern Hemisphere's largest wooden-framed hangar - 98 metres wide

[onetrack]

This is an interesting exercise by Air NZ, they've built the Southern Hemisphere's biggest hangar, 98 metres wide - capable of taking a B777, a B787, or two A320/321's, side by side - and it's almost entirely made of timber.

 

The hangar frame is constructed from Laminated Veneer Lumber (LVL) and Cross-Laminated Timber (CLT) with minimal amounts of steel (just steel baseplates, and a steel frame to support the massive wooden door), and the roof is clad with ETFE (Ethylene Tetrafluoroethylene) cushions (or pillows) that are inflated at a low pressure.

 

This unique structure has the major advantage of being able to flex up to 300mm so it can cope with seismic events (and high wind forces, too, I guess). I'm guessing termites pose no problem in NZ!

 

I find it interesting that no construction cost has been mentioned in the article, and especially no comparison to the cost of a steel-frame and steel-clad structure.

 

I would imagine that a lower cost differential for the wooden frame - if any - would come back to the fact that NZ has enormous supplies of timber, which would quite likely be much lower cost than imported steel.

However, I did note that the CLT came from Australia! I find that a bit surprising, but it may be, that NZ doesn't have the necessary manufacturing facilities for CLT yet.

 

The interest part about CLT and LVL is that they're both a lot more fire resistant than regular timber.

The glues used in them don't support combustion, and the two products resist fire taking hold because of their design, and they only char on the outside, when set on fire.

 

Air NZ's Record-Breaking Timber Hangar is Ready to Take Full Flight

WOODCENTRAL.COM.AU

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Air New Zealand's Hangar 4 has reached a major milestone following the installation of its 27-metre-high and 80-metre-wide hangar door. Engineered by Finnish ma

 

ETFE Material Guide | Building Materials for Modern Design

FABRITECTURE.COM

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Learn about ETFE material, its uses, benefits, and applications in modern building design. Discover why ETFE is a top choice for sustainable architecture projects.

 

Edited Wednesday at 12:02 AM by onetrack

[sfGnome]

As an amateur carpenter, I love laminated timber construction. You walk into a building with exposed laminated beams and it just feels warm. So much nicer than lumps of steel. I’m intrigued by the ETFE pillows for the roof. I wonder how they’d go with large hail? Would the springiness absorb the energy and cause the hail to just bounce off it like a trampoline? Impressive. 

[onetrack]

Yes, the durability of the ETFE pillows under a major hail attack has been tested, and found wanting. The Zurich Zoo has a large structure called the Masoala Rainforest building, which was built in 2002 with an ETFE pillow roof.

 

Within a week of being completed, the MR building was hit with a massive hailstorm, comprising odd knobby hailstones up to 70mm in diameter! The roof was destroyed, and had to be replaced.

 

When it was replaced, a redesign was introduced, with another separate ETFE membrane (also inflated) positioned above the main roof. A second major hailstorm hit the MR building again in 2004, and the protection membrane worked, and no damage was done to the main roof pillows - although the protective membrane was perforated in some places. It was not replaced, so I guess it was simply patched (they use adhesive tape to seal holes).

 

It appears both the original roof, and the protective membrane of the MR building, are still in place.

 

https://iibec.org/wp-content/uploads/2024/04/2007-Flueler.pdf