Materials susceptible to changes in properties

Some materials may undergo changes to their properties when they are exposed to certain environmental conditions which may affect their performance over time. Materials that are susceptible to changes in their properties may be used in building work where these changes do not adversely affect their performance. Such material will meet the requirements of the Building Regulations provided that their final residual properties, including their structural properties, meet both of the following conditions – (a) residual properties can be estimated at the time of their incorporation in the work; and (b) residual properties are shown to be adequate for the building to perform the function for which it is intended for the expected life of the building.