Hollowcore report released

Please note the information on the Hollowcore report article has been amended as 12 July 2010.

This article announced the release of the Hollowcore Floor Overview Report on investigations into the use of hollowcore floors in New Zealand, and their likely performance when subject to shaking from a strong earthquake.

The article recommended that owners who may have concerns should employ a suitably qualified structural engineer to review the building and hollow core details. That advice remains. However, in light of more recent knowledge the Department has decided to remove the Hollowcore report from the website. More updated information is provided in Codewords 24, Practice Advisory 5, the draft version of 'Seismic Performance of Hollow Core Floor Systems, Guidelines for Design Assessment and Retrofit' [PDF 2.34 MB, pages 172] and the paper by Fenwick and Bull published in SESOC Journal Volume 23 No 1, April 2010.

Research into the earthquake behaviour of hollow core floors is ongoing, as are efforts to produce guidelines for design assessment and retrofit. The Department recommends that designers keep themselves informed of developments.