NOTE 1 The hydrostatic pressures exerted by floodwater can cause sudden or long-term structural damage and undermine the foundations of a building or cause leakage through the walls, floor or sub-floor, unless the building is specifically designed to withstand such stresses. Typically, residential buildings are not structurally capable of excluding flood water above 600 mm deep (see BS 85500 for guidance). The actual water level that can be safely retained by the external walls depends upon the construction, type, form, age and condition of the walls. It is advisable that an appropriately qualified building surveyor, civil engineer or structural engineer inspects the external walls, before any flood resistance product for building apertures is installed.
NOTE 2 Flood resistance products are normally intended to prevent water more than 540 mm above the aperture threshold level from entering the building. An allowance of 60 mm has been assumed to allow for the aperture or entrance threshold against which the lower edge of the product seals.
NOTE 3 The test conditions given in Annex A represent typical conditions that can be experienced during a flood. This includes testing the flood resistance product for leakage under static water levels, waves up to 0.1 m high and parallel currents up to 1.0 m/s.
NOTE 4 This British Standard does not cover testing with contaminated or saline water; however, product manufacturers are required to provide information about the performance of their products in these conditions (see Annex B).
NOTE 5 Ongoing and scheduled repair and maintenance of components covered in this British Standard might be essential to ensure their long-term reliability and effectiveness. Instructions on these aspects of the product are provided by the product supplier. For details, see CIRIA Code of practice and guidance on property flood resilience [1]. After care and maintenance forms parts of the user manual.
This British Standard does not cover groundwater protection systems, where groundwater rises up through the foundations. This British Standard is not applicable to temporary or demountable flood resistance products which are designed to be installed away from and not attached to buildings (including flood resistance products intended for installation across driveway entrances and gateways at property boundaries). These are covered by BS 851188‑2. This British Standard is not applicable to penstocks for use in water supply, sewage treatment and other liquid flow applications, which are covered by BS 7775. It is also not applicable to anti-flooding devices for faecal and/or non-faecal wastewater for use in drainage systems of buildings operating under gravity, which are covered by BS EN 12056‑1. This British Standard does not cover flood resilience products designed to enable rapid recovery from flooding. Products covered by this British Standard are designated as flood resistance products.
