18 Oamaru stone 1

 Oamaru stone 1 - 25 March / 15 May 2016

Stonemason Pete Dunns came in early on Good Friday and started the deconstruction work on the gables.
Both gables were deconstructed in just a few hours.
Pete introduced me to deconstructing Oamaru stone by showing how it's done and he gave me some tools I to use.
Pete also took off the top courses of the wall containing the heavy soffit slabs and the corbels underneath.

The house was built in 250 and 330 mm high courses in both interior and exterior Oamaru stone masonry.
All Oamaru stone work, including all feature elements like lintels, sills and the horizontal red brick masonry, are subject to the height of the course it sits in.
By working the same course heights inside and outside, the 115/50/115mm perimeter cavity wall was easily be bridged with 280mm wide solid sills, lintels and corbels.

Throughout the house the beds between the courses (horizontal joints) were soft and there was hardly any adhesive.
For the vertical joints Pete had expected that only the joints between critical stones, in corners or next the feature elements, had been joggled and cemented.
However, the stonemasons had joggled and cemented every vertical joint in this house.
All vertical joints therefore were very hard and basically every Oamaru stone (interior and exterior) had to be broken out.

The Oamaru stone used is of a dense (good) quality and Pete estimated it would weight approx. 1.850 kg/m3
(Oamaru stone currently used weighs approx. 1.650 kg/m3)
Stones used in the house were up to 1.230 mm long,making them weight up to 90 kg (330mm course) and 70 kg (250mm course) each.
The walls are 3.44 meter high.

Once the Oamaru stone perimeter wall had been taken down to the course of the lintels, the scaffolding could be removed.

The lintels were taken out by a crane and transported to West Melton storage separately.

Now the bulk of the work was left over; taking down the Oamaru stone walls was going to be a huge job.
I was in for it, however, since we were going towards winter, days were getting shorter and daylight saving would be over.

Soon it was going to be dark at 7pm.
For this last stage in the deconstruction I decided to quit my job to be able to work full time on the deconstruction of the house.
During my 4 weeks’ notice period I worked through the evenings with artificial light.