Failure modes and effect analysis (FMMEA) used on moisture problems

Preventing “damp” buildings will give a better indoor climate and less risk of health problems for the inhabitants. Many industries use FMEA (failure modes and effect analysis) to reduce the risk. This method is new in the building sector. Part of an analysis of a building and the installations is presented. The failure mode table gives the possible failure modes from free water. Based on the failure modes can the effects for each failure be found and prevention measures can be taken. Some modes are easy to see others are hidden and will first be seen if something else fails. In the future it should be possible to calculate the risk levels and compare different solutions. The FMEA analysis can be used in planning and building of new houses, but also as help in preventing failures in existing buildings. INDEX TERMS Moisture, Failure modes, Maintenance, Technical installations, Building construction INTRODUCTION “Dampness” in buildings gives a higher risk for health problems (Bornehaug et al., 2001), than dry buildings. It is therefore important to reduce the risk of moisture damage in buildings. As we do not know the coupling between moisture and health we must regard excess moisture as a problem. The traditional method for solving moisture failures is to fix it, when found. We need a more systematic method to avoid future moisture failures. Solving similar failure problems is important in many types of stationary industry (Moubray, 1999) (O'Connor, 1995) as production of aircrafts, cars and computers. The producers want to prevent failures by analysing the systems before production and having a feedback from accidents. This is done in the airline industry, where every accident is analysed to find the causes. After each accident a number of changes in the design or in the maintenance is suggested. Finding failure modes and analysing the effects of the failures can also be used in the building sector. FAILURE MODE AND EFFECT ANALYSIS (FMEA) Failure mode and effect analysis (FMEA) is described in (US MIL STD 1629, 1980). It is intended to recognize and evaluate the potential failures of a product (the house) or process (construction) and find effects of failures. It will identify actions that can be taken to prevent failures by elimination or reducing the chance of occurrence. The concept of FMEA is not new. Designers have always thought of failure modes and how to prevent them. The FMEA method is new in the building sector and gives a more systematic approach. The building sector has many rules and guides for building without problems. The building sector is different from most stationary industry as only part of the building process is industrialized. Many operations are not repeated and the work is adjusted on site. The workmanship is therefore important for the result. Both human and technical errors must be included in the ∗ Contact author email: anker.nielsen@sp.se Proceedings: Indoor Air 2002