Last edited 07 Dec 2018

Burland scale

The Burland Scale is used to describe or measure the damage (or risk of damage) to properties as a result of changes such as subsidence. It may be used for example to assess the risk of damage as part of a basement impact assessment.

It categorises the damage to properties as:

Where:

  • Categories 0, 1, and 2 refer to (i) aesthetic damage.
  • Category 3 and 4 relate to (ii) serviceability and function.
  • Category 5 relates to (iii) stability.
Category of damage Description of typical damage Approximate crack width (mm) Limiting tensile strain εlim (%)
0 Negligible Hairline cracks of less than about 0.1 mm are classed as negligible <0.1 0.0-0.05
1 Very slight Fine cracks that can easily be treated during normal decoration. Perhaps isolated slight fracture in building. Cracks in external brickwork visible on inspection <1 0.05-0.075
2 Slight Cracks easily filled. Redecoration probably required. Several slight fractures showing inside of building. Cracks are visible externally and some repointing may be required externally to ensure weathertightness. Doors and windows may stick slightly. <5 0.075-0.15
3 Moderate The cracks require some opening up and can be patched by a mason. Recurrent cracks can be masked by suitable lining. Repointing of external brickwork and possibly a small amount of brickwork to be replaced. Doors and windows sticking. Service pipes may fracture. Weathertightness often impaired. 5-15 or a number of cracks > 3 0.15-0.3
4 Severe Extensive repair work involving breaking-out and replacing sections of walls, especially over doors and windows. Windows and frames distorted, floor sloping noticeably. Walls leaning or bulging noticeably, some loss of bearing in beams. Service pipes disrupted. 15-25 but also depends on number of cracks >0.3
5 Very severe This requires a major repair involving partial or complete rebuilding. Beams lose bearings, walls lean badly and require shoring. Windows broken with distortion, Danger of instability. Usually > 25 but depends on number of cracks

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