scope:

This Standard sets out construction requirements for concrete masonry buildings not requiring specific engineering design within the limitations specified by 1.1.3. It is intended as a means of compliance with the following requirements of the New Zealand Building Code (NZBC):

(a) Clause B1 Structure

Masonry constructed in accordance with this Standard and NZS 4210 will meet the requirements of B1.3.1, B1.3.2, and B1.3.4 for loads from B1.3.3(a), (b), (d), (f), (h), and (j), that is for loads arising from gravity, earth pressure, earthquake, wind, and human impact. This Standard covers masonry constructed to Observation Type B as defined in NZS 4230. Appendix A gives details of concrete masonry walls that are retaining soil. Appendix B gives details of free-standing cantilevered concrete masonry walls;

(b) Clause B2 Durability

Masonry constructed in accordance with this Standard will be durable for at least 50 years and will therefore meet B2.3.1(a) of the New Zealand Building Code;

(c) Clause E2 External Moisture

Construction in accordance with this Standard will ensure against damage to building components or dampness in the building as a result of external moisture entering through the masonry walls or the concrete slab-on-ground. This Standard ensures compliance with E2.3.2 and E2.3.3 of the New Zealand Building Code for walls and floors only. This Standard is not a complete solution to Clause E2 as it does not contain provisions for the other elements of the building envelope such as roofing, exterior joinery, and flashings.

Where this Standard has provisions that are in non-specific or unquantified terms (such as where provisions are required to be appropriate, adequate, suitable, and the like), then these do not form part of the means of compliance with the New Zealand Building Code and shall be to the approval of the building consent authority.

This Standard does not provide complete information on the use of timber components and reference to NZS 3604 is required.

This Standard applies only to buildings within its stated limitations, including but not limited to:

(a) Buildings shall be founded on good ground;

(b) Buildings shall be Importance Level 1 or 2 (see Table 1.1);

(c) The total height from the lowest ground level to the highest point of the roof shall not exceed 10 m and no storey height shall exceed 3 m;

(d) The ratio of the total building height to minimum building width shall not exceed 2.5;

(e) The plan footprint floor area and configuration of construction shall comply with the limitations contained in Figure 1.1 and shall not exceed:

(i) 600 m² for single-storey masonry buildings

(ii) 250 m² for two-storey residential masonry buildings

(iii) 350 m² for two-storey residential buildings where the upper storey is constructed of timber and the external wall of the lower storey is of masonry supported on a concrete slab-on-ground, concrete or masonry footings or masonry foundation walls

(iv) 250 m² for two and two-storey with attic buildings constructed with upper storey or storeys of timber supported on a lower storey of masonry with the top storey contained within a roof space;

(f) The live load on concrete slab-on-ground shall not exceed a uniformly distributed load of 3.0 kPa nor a concentrated load of 9.0 kN;

(g) Concrete slab-on-ground floors in accordance with 7.8 may be used for vehicle garages for vehicles up to 2500 kg tare;

(h) The slope of any roof plane shall not be steeper than 45° to the horizontal.

(j) Roofs shall be of timber complying with NZS 3604 with the following additional requirements:

(i) The live load on the roof shall not exceed 0.25 kPa

(ii) The top plate supporting the roof shall be 140 mm x 45 mm SG 8 or better graded timber

(iii) The top plate shall be fixed to the top of the masonry wall with M12 bolts cast in a minimum of 75 mm and placed at a maximum of 300 mm from any corner and at a maximum of 1200 mm centres elsewhere in Low and Medium Wind Zones and at a maximum of 600 mm centres in High, Very High, and Extra High Wind Zones;

(k) Suspended timber floors shall be of timber construction complying with NZS 3604 unless otherwise modified by this Standard;

(m) Suspended concrete floors used as a diaphragm shall meet the requirements of this Standard for horizontal loads and shall for the purposes of other structural functions be required to be specifically designed to NZS 3101. The maximum dead load of suspended concrete floors shall not exceed 4.5 kPa;

(n) All walls shall be constructed in running (or stretcher) bond pattern;

(o) In the case of masonry veneer exterior cladding:

(i) The maximum height of veneer shall be 6 m measured from the top of a supporting concrete masonry or reinforced concrete foundation or a slab edge foundation except that, if at a gable end, the overall height can be increased to 10 m

(ii) All masonry veneers shall be constructed in running (or stretcher) bond pattern

(iii) Where construction adjoins a public place or egress and the veneer is in excess of 6 m in height the veneer construction shall be the subject of specific engineering design

(iv) Where a timber framed upper storey has been used then the maximum height above the masonry substructure shall not exceed the provisions of NZS 3604

(v) The maximum mass of veneer covered by this Standard is 220 kg/m².