More strengthening work was done this week. It included extra steel strapping and carriage bolts. Also added were 12 serious brackets in the base of the wall frames, anchored deep into the concrete foundation.
The bracket product, GIB HandiBrac, was insisted on by the building inspector last week. Bruce had already secured the wall plates by the traditional bolts pre-inserted into the concrete foundation, and strengthened the frames with angle steel. The Handibrac system is used in corner areas where special high performance GIB Braceline plasterboard will also be installed (the Braceline sheets were also a new requirement).
One advantage Handibracs have over traditional bolts is that they lock together studs as well as concrete and the plate.
All this is way beyond requirements of just a few years ago and seems to reflect hightened paranoia on the part of building and municipal authorities following the Christchurch earthquakes.
I gather, though, that the main justification for insisting on this overkill was protection against strong north-west and south-east winds.
Whatever…it all adds up to considerable extra expense for us and is probably unneccessary. The existing part of the house, built to hugely lower specs, has survived hurricane-strength winds and severe earthquakes for nearly 100 years.
The video below (complete with sound effects from the truck radio and Bruce’s own commentary) shows the ‘BOWMAC screw bolt being banged into a hole drilled through the wooden frame and into the concrete. After hammering the bolt part of the way, the job is completed with a wratchet spanner.