Brick Durability – Brick Salt Attack Resistance

This article was updated on the 3rd October 2019.

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All brick products manufactured in Australia and New Zealand are classified in terms of their durability. Put simply, durability is the resistance of the brick to attack by soluble salts. Not every brick is suitable for all applications, therefore, bricks must be classified to determine their degree of resistance and their most appropriate use.

According to the standard AS/NZS 4456.10, bricks are organized under the salt resistance categories listed below. The applications where these various categories are to be used are detailed in AS3700-2001, Masonry Structures.


Exposure Grade

Suitable for use in external walls exposed to aggressive environments such as:

  • Walls where there is possible exposure to salts in the soil or groundwater
  • Walls exposed to attack from windborne salt spray
  • Retaining walls

General Purpose

Suitable for use in an external wall under ordinary exposure conditions.


Suitable for use in an external wall only above a sheet or membrane damp - proof course and below an adequate coping, roof or similar top covering, protecting the masonry.

Standards AS3700-1998

AS 3700-2001 specifies that exposure grade masonry must be used in severe marine environments such as:



Note 1: In environments where exposure grade masonry is required the minimum mortar classification required is M4.

Note 2: Exposure grade bricks may not be suitable for use in areas subject to cyclic freezing and thawing.


  • Austral Bricks, Australia

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