Building Forensics and Occupant Health
January 05, 2009

Investigating Defects in UK Buildings

 

When faults appear in the building envelope or internal finishes design or construction defect are usually responsible. Failure to install adequate insulation, air movement control, sufficient rain or drainage plains and material absorbency are typical post construction faults.Failure to identify thermal bridges which cause condensation are typical issues which can cause extensive moisture development through condensation.

Missing vapour retarders often cause extensive damage to both the internal and external envelope. Poorly fitted insulation and failure to adequately overlap seams or joints is another fault waiting to cause damage.

In general terms the tight building design with limited air exchanges requires a high level of builder’s competence and supervision. Even a small gap in insulation or vapour barrier the wrong side can cause ongoing damage which can seriously reduce the life expectancy of the building.

What we do

We test the building envelope under a small positive or negative pressure via specialist equipment which can measure even minute pressure variations to assess the problem.

We use safe trace gas or special smoke to identify leakage areas.

We use infra red thermography to virtually see through walls.

We test the building envelope for integrity and assess the potential of the problems where identified.

We measure the differences between internal and external specific humidity to identify possible issues.

Typical faults identified

  • Air management and tight envelope failures.
  • Vapour retarders missing.
  • Moisture (gas phase) and air flow issues.
  • Drainage plain missing.
  • Insulation and Dew Point issues caused by thermal bridging.
  • Flashing or moisture removal failures.
  • Moisture management failures.
  • Ventilation and air management failures.
  • Moisture tolerance of assembly problems.
  • Drying and drainage potential limited and flawed.
  • Wrong use of materials and in particular the installation of a vapour barrier (polythene) on the wrong side of the construction envelope, most likely to cause massive damage.
  • Thermal bridging issues generally.
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    Typical construction defects

    Search

     
    Early moisture detection to prevent toxic mold
    Invasive investigation showing Envelope failure 46% moisture content and cause of toxic mould.
    Smoke pencil detects leaks
    Using smoke pencil to identify envelope leakage.