The successful application of moisture simulation models to building envelopes requires accurate values of material transport properties. Unfortunately, although the presently-available database is reasonably voluminous, much of the information given is of limited use. This paper describes the specification of moisture transport data in terms of the differential permeability function and proposes its most appropriate form.

The use of this function allows the accurate evaluation of permeability and total moisture flux appropriate to the humidity conditions to which a material is subjected in practice. It is also suggested that it allows the separation of the total moisture flux into its vapour and capillary liquid components, which is a prerequisite for the exact solution of the defining transport algorithms. This hypothesis has been tested using a prototype experimental procedure in which permeability measurements are made under different barometric press ures.

• HAM: material properties

1. Evaluation of discretized transport properties for numerical modelling of heat and moisture transfer in building structures
2. Moisture permeability data presented as a mathematical relationship
3. Non-contact methods of measuring moisture concentration in external layers of building partitions. I--The influence of geometrical microstructure on the kinetics of moisture condensation on glass surfaces
4. Nonisothermal moisture diffusion in porous building materials
5. The application of X-ray absorption to building moisture transport studies
6. The determination of vapour and liquid transport coefficients as input to combined heat mass transfer models
7. The effect of temperature on the moisture permeability of building materials
8. The influence of space discretization on the accuracy of numerical simulation of heat and moisture transport in porous building materials
9. The selection of appropriate flow potentials for moisture transport models  

1. A technique for the prediction of the conditions leading to mould growth in buildings
2. Development of a simulation tool for mould growth prediction in buildings
3. Evaluation of discretized transport properties for numerical modelling of heat and moisture transfer in building structures
4. Moisture permeability data presented as a mathematical relationship
5. Nonisothermal moisture diffusion in porous building materials
6. Prediction of toxigenic fungal growth in buildings by using a novel modelling system
7. The application of X-ray absorption to building moisture transport studies
8. The determination of vapour and liquid transport coefficients as input to combined heat mass transfer models
9. The effect of temperature on the moisture permeability of building materials
10. The selection of appropriate flow potentials for moisture transport models  

1. Evaluation of discretized transport properties for numerical modelling of heat and moisture transfer in building structures
2. Moisture permeability data presented as a mathematical relationship
3. The effect of temperature on the moisture permeability of building materials
4. The selection of appropriate flow potentials for moisture transport models  

1. Evaluation of discretized transport properties for numerical modelling of heat and moisture transfer in building structures
2. Nonisothermal moisture diffusion in porous building materials  

1. Measurement of diffusion coefficients of VOCs for building materials: review and development of a calculation procedure