GB/T 30801-2014Hygrothermal performance of building materials and products -- Determination of water-vapour transmission properties -- Box method (English PDF)

Foreword

This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This Standard uses translation method to make it identical with ISO 21129:2007 Hygrothermal performance of building materials and products - Determination of water-vapour transmission properties - Box method. There are following editorial changes between this Standard and ISO 21129:2007.

- modified "this International Standard" to "this Standard";

- added table title of Table 1; modified Table 1 in the ISO standard to Table 2;

- added GB/T 20312-2006 and ISO 12572:2001 in Bibliography to Clause 2.

1 Scope

This Standard specifies a box method for determining the water-vapour permeability of building materials. The box method is used primarily to measure the water-vapour permeance of materials that have low water-vapour resistance, in which the influence of the surface-humidity transmission-resistance cannot be ignored.

NOTE Materials with low water-vapour resistance includes those with no greater than 1.8 x 10^9 · m2 · S · Pa/kg of resistance [water vapour permeability coefficient of 5.5 x 10^-8 kg/(m2 · S · Pa or above)].

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 9346 Hygrothermal performance of buildings and building materials - Mass transfer - Physical quantities and definitions

GB/T 20312-2006 Hygrothermal performance of building materials and products - Determination of hygroscopic sorption properties (ISO 12571:2000, IDT)

ISO 12572:2001 Hygrothermal performance of building materials and products Determination of water vapour transmission properties

3 Terms, definitions, symbols and units