ABSTRACT
We set out the principles that govern the movement of water in brick, stone and concrete materials, and show how transport in both sat- urated and unsaturated materials can be described. We define the permeability property, how it is measured, and give values of the permeability of a wide range of materials. Darcy's law is defined for saturated materials and in its extended form for unsaturated ma- terials. Further topics include: the potential-conductivity and dif- fusivity formulations of the extended Darcy equation, and how the conductivity and diffusivity are measured; vapour diffusion; mois- ture buffering; immiscible and miscible displacement and disper- sion. There is also an historical summary of the development of water-transport topics.
