Novel approach to wall construction

Press, 19 February 1988, Page 4

Novel approach to wall construction

Rangiora reporter A Christchurch designer has developed a novel method of wall construction using a combination of Oamaru stone and polyurethane foam. , Mr John Britten, aged 37, has spend two years working on the building system which will be used experimentally for the first time on a small Rangiora garage soon to be erected. Mr Britten said there is still work to be done to perfect the system, and building the garage will give him the chance to monitor its performance. The system features a sandwich pane! construction method, where two veneers of Oamaru stone are held about 10cm apart by a specially designed wire clip. Into the cavity between the two veneers is pumped polyurethane foam, which expands to fill the entire area and bonds direct on to the

stone blocks. All window fittings, door frames, wiring and plumbing are set into the stone work before the foam is injected. The foam filling makes for a very lightweight structure, which is considered to be one of its big advantages.

Mr Britten has developed a new stone-cutting machine which gives the blocks a smooth finish, and the over-all effect of the completed wall is of a flush, even surface.

The process eliminates the need for mortar and boxing. Polyurethane foam is known for its fire-resis-tance and non-toxicity and has good insulation qualities.

Polyurethane foam has been used in wall constrution before, but Mr Britten beleives the way he has applied the material and construction concepts makes his design unique in New Zealand, and possibly the world.