# Unit Weight of Construction Materials

Unit weight or density is used to quantify the weight per unit volume of an object. When it is expressed in the basic SI Unit of mass (kg/m3), it is usually referred to as density, but when expressed in terms of weight (kN/m3), it is usually referred to as unit weight.

Density (kg/m3) = Mass (kg)/Volume (m3)

The unit weight of a material is very important in calculating the self-weight of the material, especially when evaluating the permanent actions in a structure. Without the knowledge of the unit weight of a material, it will be impossible to accurately estimate the bodyweight and the load it subsequently carries when used as a structural member. This article is dedicated to providing a handy list of the unit weight of various construction materials according to EN 1991-1-1:2002.

The density of a material can vary depending on the composition, process of manufacturing, and other factors. However, the density of man-made products is fairly constant (or controllable) when compared with the density of direct products of nature. Therefore, natural materials are expected to have slightly different properties even when they are occurring in the same place.