AS 4773.2:2015 Masonry in small buildings
3.1 MORTAR TYPES
Mortar types shall be as specified in the documents but their durability shall be not less than the requirements given in Table 3.1 and Table 3.2. The mix proportions shall comply with the following:
(a) Mortar mixes shall be designated by the materials and proportions of their ingredients. They shall be set out in the order of parts of cement : lime : sand.
NOTE: These proportions are sometimes preceded by the letter that abbreviates the material.For example, C1 : L0.5 : S4.5 is one part cement : half a part lime : four and a half parts sand.
(b) The water thickener referred to in Table 3.2 is methylcellulose based. The particular methylcellulose-based product used shall be specifically suited for this application.
NOTES:
1 The methylcellulose-based product should be used in accordance with the manufacturer’s or supplier’s instructions.
2 Air-entraining agent is not the same as methylcellulose-based water thickener.
3 Volumes in Table 3.2 refer to those materials in the dense-packed condition.
(c) Type SR cement shall be used in masonry below the damp-proof course in areas with sulphate-rich ground water.
NOTES:
1 All external elements in contact with freshwater or subject to non-saline wetting and drying shall be treated as for a marine environment. For example, this applies to gardens against a house.
2 All external elements in contact with saline or contaminated water, or subject to saline wetting and drying, shall be treated as for a severe marine environment.
3 Requirements for especially aggressive environments depend on the nature of the corrosive agents and cannot be defined. Units, mortars, covers or coatings, shown by test or know by experience to be resistant to the particular corrosive agent, shall be used.
4 M2 mortar is not permitted for concrete and calcium silicate masonry. There are also limitations on the constituents of M3 and M4 mortars for calcium silicate masonry (see Table 3.2.).