Steel mesh testing to be strengthened

  • Nick Smith
Building and Housing

Consultation on proposed changes to the Building Code to strengthen steel reinforcing mesh testing requirements has opened today, Building and Housing Minister Dr Nick Smith says.

“The Government is tightening the requirements for verifying that steel mesh used in New Zealand matches up to our standards. We are increasing the number of tests required, clarifying exactly how the tests are done and requiring the tests to be undertaken by internationally accredited testing laboratories,” Dr Smith says.

“There have been issues with the quality of a small amount of steel mesh, which the Commerce Commission is investigating. The updated Verification Standard and Acceptable Solution will apply to all steel mesh of Grade 500E being sold in New Zealand, whether made locally or imported. This will make it absolutely clear to the industry exactly what should be tested and the standard to which that must be done. It will help ensure the product meets our 10 percent ductility requirements for residential buildings – and gives certainty to the public that the mesh used in new houses is fit-for-purpose.

“The issue that has caused concern is ductility, or the capacity of mesh to retain its strength when stretched. The rules were toughened in response to the Christchurch Earthquakes so that all new homes had to have steel mesh of 10 per cent ductility to increase the resilience of floor slabs after a quake.

There have been problems with suppliers meeting both the old and new standards, and disputes over how they are applied. These new requirements will better ensure consistency and compliance.

“The building industry is booming and this is putting additional pressure on our quality assurance systems. This is one of more than 30 changes we are making to Building Code compliance documents to ensure we get both quality and quantity.”

The Verification Method and Acceptable Solution changes are out for consultation until 8 September. The proposed changes come into effect on 7 October except for the requirement for accredited testing, which is effective from 1 January 2017.

“These new requirements mean additional testing capacity will be needed in New Zealand. We currently have two accredited laboratories and International Accreditation New Zealand has additional applications being processed. This increased investment in quality assurance is needed to ensure our building materials match up to the required standards, particularly given the current building boom.”