Nothing is absolutely dry. Water, in the form of liquid vapour, will always exist bound up in building materials as well as in the air. A building will be perceived as being dry if the moisture present does not pose a problem for its inhabitants or contents.
An underground carpark at 75% relative humidity, but which has a few minor damp patches in out of the way corners, and maybe some condensation on the walls, may be considered to be dry. Whereas an office, which has no visible dampness at all but has a relative humidity of 75% would be perceived as damp, because papers could curl and the occupants would find the atmosphere muggy.
Basement Performance Levels of BS 8102 defines the performance levels for the dryness of buildings in four grades, as follows:-
|1||Car Parking, Plant Rooms, (excluding Electrical Equipment), Workshops||Some seepage and damp patches tolerable|
|2||Workshops and plant rooms requiring drier environment, retail storage areas||No water penetration but moisture vapour tolerable|
|3||Ventilated residential and working areas, including offices, restaurants, leisure centres, etc||Dry environment|
|4||Archives and stores requiring a controlled environment||Totally dry environment|
See our range of materials in our online store
Please don't hesitate to contact us for more specific advice on which grade is appropriate for your project.
Posted 11:36 PM | Permalink