Wall Densities

You may need to know the wall densities of our products for the energy efficiency section of the Building Code of Australia (BCA). The density of a wall can be an indication of the amount of thermal mass in the wall.

Materials with thermal mass have the ability to moderate temperature swings naturally. Thermal mass is a different property to the R-value (or insulation level) of a material. The Building Code of Australia has recognised this through special provisions for external walls that have a wall density greater than 220kg/m2. Constructions that have higher thermal mass typically require less added insulation according to the BCA provisions.

Wall Densities

The wall densities (kg/m2) have been determined for the Clay Brick Product Range and are given in the table below.

Note: Wall densities have been determined by calculation from nominal average product weights, nominal sizes and assumed mortar properties. Variations will lead to a different wall densities. The following assumptions about the mortar has been made: mortar density has been estimated as 1900kg/m3, all perpend and bed mortar joints are assumed to be completely filled, perpend and bed mortar joints are assumed to be standard 10mm. In the calculations below, render is assumed to have a density of 1900kg/m3.

Examples

The wall density of a brick veneer construction or a reverse brick veneer is essentially the same as the wall density of the single skin of brickwork. For example, a brick veneer house built with Almond bricks from the Urban One Range would have a wall density of 153.3kg/m2. A rendered brick veneer would have a wall density equal to the sum of the brick wall density and the render wall density. For example, a rendered Standard 76 veneer would have a wall density of 22.8kg/m2 (12mm render) plus 177.5kg/m2 (bricks) equalling 200.3kg/m2. The following table can be used to determine the wall density of a rendered brick veneer:

The wall density of cavity brick construction is equal to the sum of the parts. For example, a cavity brick house built with Millenium Red face bricks and internal rendered Maxi 119 bricks would have a wall density of 177.5kg/m2 (external bricks) plus 129.4kg/m2 (internal bricks) plus 22.8kg/m2 (12mm internal render) equalling 329.7kg/m2. The tables below can be used to determine the wall densities for a number of cavity brick construction styles.