Masonry in New Zealand
Concrete masonry — concrete blocks used in reinforced masonry construction — is a significant part of New Zealand’s commercial, industrial, and some residential construction. Masonry construction offers durability, fire resistance, acoustic mass, and thermal mass that make it well suited to certain building types: warehouses, schools, retail buildings, boundary walls, and some residential construction in areas where fire separation or durability requirements favour masonry over timber frame.
Reinforced masonry in New Zealand is governed by NZS 4230 (Design of Reinforced Concrete Masonry Structures), and structural masonry construction requires specific construction practices — correct block laying, grout filling, reinforcing placement — to achieve the structural performance the engineer has designed for.
Block Types and Specifications
Concrete masonry blocks in New Zealand are produced to NZS 3102, which specifies the dimensions, tolerances, and minimum strength requirements for different block types. Standard blocks are 390mm long × 190mm high × varying width (100mm, 140mm, 190mm, 240mm are common). Hollow blocks are the most common — the cores are filled with grout and reinforcing to create the structural masonry system. Face blocks with textured or coloured finishes provide an architectural alternative to plastered masonry.
Grouting and Reinforcing
The grout fill and reinforcing placement in masonry construction is critical to structural performance. The engineer’s drawings specify the reinforcing bar size, spacing, and lap lengths; the grout must be placed to completely fill the cores without voids (which would compromise the structural capacity). Regular inspection of masonry cores before grouting — to confirm reinforcing placement — and careful grout placement and vibration are quality management essentials in structural masonry construction.