What is this BS 5250+A1 about?
BS 5250+A1 gives recommendations and guidance on avoiding problems with high moisture levels and condensation in buildings. Recommendations given are based on forms of construction commonly adopted in the UK.
BS 5250+A1 gives guidance on the risks associated with excessive humidity in buildings, notably mould growth and condensation, which can endanger the health and well-being of building occupants and the integrity of the building fabric. It describes the principal sources of water vapour, its transportation, and deposition and provides guidance on how to manage those risks during the design, construction, and operation of buildings. The guidance contained in BS 5250+A1 is relevant to buildings of all types, whatever their form, construction, and occupancy.
Note:
BS 5250+A1 does not cover buildings used for storage at sub-zero temperatures. Recommendations and guidance on how to avoid penetration of the building envelope by water is contained in other British Standards, for example
BS 8103-1, BS 8103-3 and BS 8103-4 for floors, BS 8103-2 and BS 8104 for walls, BS 5534 for pitched roofs, and BS 6229 for flat roofs.
BS 5250+A1 covers:
- The essential relationship between temperature and moisture content of air
- Methods of calculating the risk of surface and interstitial condensation
- Typical quantities of moisture generated in buildings of various uses and levels of occupation
- Thermal conductivity and vapour resistivity values of common building materials
- Factors for the conversion of common units
Who is this BS 5250+A1 for?
BS 5250+A1 on code of practice for control of condensation in buildings are useful for:
- Construction industry
- Technical authority
- Civil engineer
- Designer of building
- Manufacturer supplier and installer of building
Why should you use this BS 5250+A1?
Moisture in buildings arises from several sources if not properly controlled it can lead to mould growth and condensation problems which affect about 15% of homes. The requirement for more efficient use of energy in the operation and use of buildings has led to increased levels of thermal insulation and airtightness in both new and refurbished buildings; this has led to an increased risk of damage from condensation.
BS 5250+A1 sets the side of caution and adopt robust fail-safe solutions bearing in mind that occupants often fail to use buildings in the manner intended, be it by choice, lack of understanding, or force of circumstance. This will help you to refurbish a building or make changes to its use, the risk of condensation must be re-assessed considering the new usage.
Overall, BS 5250+A1 helps the user to understand the design intent, together with good workmanship under proper supervision, which can then result in a healthy environment within a durable building envelope.
What’s changed since the last update?
BS 5250:2011+A1:2016 supersedes BS 5250:2011, which is withdrawn.
Text introduced or altered by Amendment(s) No. 1 is indicated in the text by tags. Minor editorial changes are not tagged.