Repair of moisture and mould damage

YHA Kuvapankki / Pentti Hokkanen

Mould dogs — unregulated industry lacks guidance

Mould dogs are being increasingly used to assist in the investigation of indoor air problems in Finland. No unified system, however, exists for verifying qualifications for dogs or their handlers. As a stop-gap remedy, in March the Programme to Combat Moisture and Mould Damage published guidelines for mould dog handlers and customers. A recent survey on the subject of mould dogs, directed at municipal employees handling matters relating to indoor air quality, revealed a desire for the rapid harmonisation of certification within the industry.

Mould dogs do not have official status like sniffer dogs or police dogs, and are thus not subject to any official certification or competence-testing system organised by the state or authorities. Competence testing of mould dogs and their handlers is also not provided for in legislation, nor would such legal provision be simple to arrange. Finland also lacks a voluntary system for testing the competence of mould dogs and their handlers.

It is hoped that the new guidelines issued under the moisture and mould programme will clarify mould dog operations, standardise inspections carried out by mould dogs and improve the quality of reports drawn up on such inspections. The guidelines are available free-of-charge on the programme's website at

Kymen Home-etsintä

Three out of four mould dog users would recommend the use of dogs in the detection of moisture damage

As part of her Master's thesis, Karoliina Viitamäki investigated the experiences of municipal and city workers dealing with indoor air quality issues who have used mould dogs. While the results are only suggestive, they do lend weight to the case for a system of competence testing.

The survey charted the opinions of experts and authorities on mould dog activities and on areas needing improvement. The main finding was that the industry requires a system of competence testing. A list of mould dog entrepreneurs should be drawn up to enable customers to easily find entrepreneurs and dogs that have passed the competence tests. According to the responses, the main obstacles to using mould dogs were lack of official instructions on their use, difficulties in interpreting mould dog inspection reports, and ambiguities in such reports, which had made some respondents suspicious. These obstacles could be eliminated by creating standardised tests for the industry and, possibly, a list of mould dog entrepreneurs who have passed the required competence tests.

One quarter of those who had used mould dogs in their work described them as extremely useful in detecting moisture damage, and one half described them as useful. Three in four mould dog users intend to use them again and to recommend their services.

Additional information is available from:

Karoliina Viitamäki, Analyst
tel. +358 40 531 0365


Decentralisation of responsibility and shortcomings in the flow of information are highlighted as pitfalls in moisture and mould repair projects

Decentralisation of responsibility and poor flow of information between the parties concerned are among the most common reasons for failure in municipalities' moisture and mould damage repairs, reveals the M.Sc. thesis of Paavo Kero (M.Sc. Tech.). The thesis, completed as part of the Moisture and Mould Programme, monitored repair sites owned by municipalities.

The project followed the moisture and mould repair process on five sets of premises owned by municipalities. Looking at these sites, of various types, the study examined how moisture and mould problems are found and how sites are prioritised, planned, repaired, communicated on, supervised, and monitored. The target sites were selected from among those receiving moisture and mould repair subsidies from the Regional State Administrative Agency for Southern Finland.

Problems emerge around decentralisation of responsibilities and poor flow of information

YHA Kuvapankki / Pentti Hokkanen

The study revealed that defective real-estate management can contribute to moisture and mould damage arising. It can also hamper the examination of reasons for problems. ‘Any problems detected should be reacted to quickly, and their causes must be examined,' says Kero.

Fragmented ownership and management of repair sites, and problems in financing of the projects, may delay the launch of inspections. On account of the lack of prioritisation methods, municipalities also find it hard to select estates that should be repaired. At the sites monitored in Kero's research, responsibility for leading the repair process was transferred from party to party at various stages in the process, and major defects were found in communication between the parties concerned.

The results of damage inspections and destructive testing carried out at the repair sites were not communicated with sufficient accuracy to those in charge of planning or implementation of the repairs. For that reason, repair measures could not be targeted correctly,' explains Kero.

The planning solutions applied in moisture and mould repairs differ significantly from those utilised in new buildings. In planning of repair solutions, the interrelationships of different parts of the building, and technical systems, should be known quite precisely. According to the study, not enough information is available on the functionality of various repair methods.

‘Instead of repairs, consideration of the whole would have been sensible at some of the sites studied: is the estate worth repairing, or would it be more economical, for instance, to find completely new premises for the activity in question?' Kero muses.

His MSc thesis forms part of the research project launched by the Ministry of Social Affairs and Health and the Ministry of the Environment a year ago, aimed at assessing procedures for repairing damage and producing recommendations on the operating instructions needed. Kero's master's thesis was published in August.

YHA Kuvapankki / Pentti Hokkanen

Help for assessment and monitoring is available

The project continues at the Tampere University of Technology with the development of a practical assessment and monitoring form in support of the research project. This form collects project information in one location and ensures that all sectors are taken into account. The form is suitable for use in all repair projects and, as it is written in everyday language, serves as a source of comprehensive information for the general public, not just professionals in the construction sector.

‘Repair projects' success always depends on the entire chain. Major problems can be seen in the areas of communication and decentralisation of responsibility. In the worst case, no-one can see the bigger picture or takes overall responsibility for a project,' summarises Kero. In practical terms, this may mean, for instance, that base floor damage at the site is repaired but not a leaking roof covering - repair costs and schedules are overrun, and communications takes place mostly through the local newspaper.

The form, described as a practical assessment and monitoring tool, enables prediction and reduction of risks. It collects basic data on the project and facilitates assessment of the impacts of repairs on adverse health effects and the building's technical useful life.

The monitoring form enables outsiders to gain an overall sense of the repair project quickly, and others apart from building technology professionals are able to assess the repair project. Information is not lost, and key issues are analysed. The form also increases the transparency of the project and makes the division of responsibilities clearer, according to Kero.

The practical assessment and monitoring form is intended for completion next spring, and it will be available on the Web sites of the Moisture and Mould Programme and the Tampere University of Technology's Department of Civil Engineering.

For more information, please contact:

Tampere University of Technology's
Paavo Kero
Phone 040 198 1283


Protection and cleaning particularly vital in repairs of moisture and mould damage

Prevention of mould dust from spreading and proper cleaning play a key role in repairs of moisture and mould damage. Correctly executed protection and cleaning reduce the exposure of both building occupants and repair workers to mould dust. Appropriate protection also makes cleaning much easier after repairs. The special guide on the protection and cleaning of locations under repair has now been completed and updated as part of the Moisture and Mould Programme.

When structures with mould damage are demolished and repaired, the amounts of mould dust in indoor air may multiply greatly, becoming up to a million times higher than in the initial situation. The health of other occupants of the premises, and movable goods, can be protected through isolation of the area under repairs, to stop mould dust from spreading.

´Property-owners, in the private and public sector alike, should demand appropriate protection of premises and employees during repairs, and proper cleaning, even at the stage when quotations are requested. Skilled professionals must be employed for both repairs and cleaning tasks,' emphasises Jouko Leppänen, Executive Manager of Suomen JVT- ja Kuivausliikkeiden Liitto ry (the Finnish Federation of Subsequent Damage Prevention and Drying Businesses).

Appropriate protection and cleaning during the actual renovation simplify and minimise the complete cleaning that is required to make the premises mould-free after repairs. It is vital to wear personal protective equipment at work in order to prevent mould dust and mould smell from coming into contact with the lungs, mucous membranes, and skin. This applies to repairs commissioned by housing companies and individual residents alike.

‘The lack of negative pressurisation, protection, and proper cleaning may be due to ignorance on the part of the contractor or the party commissioning the work, or intent to save money. In these cases, residents have to attend to the cleaning of furniture and other movable goods after the renovation - and pay for it, too. In the worst-case scenario, the resident and even neighbours may suffer from coughing, head colds, or other symptoms for months on end after the renovation,' comments Juhani Pirinen, Programme Director of the Moisture and Mould Programme.

Complete cleanup of mould requires special expertise

‘During renovation, contaminants spread easily through ventilation ducts and on repair workers' clothes to corridors and other areas. Whenever structures are demolished, the area under repairs must be protected carefully. You must ensure that no-one leaves the site in work clothes. In fact, structures with mould damage should be demolished in accordance with the same procedures as when asbestos is present,' instructs Leppänen.

Studies have shown that ordinary site cleaning is not sufficient to remove the dust and smell from moulds properly. Therefore, complete cleanup of mould and cleaning of movable goods must be carried out after the site cleaning itself. The aim is to eliminate mould dust and smells. Properly conducted cleanup promotes the successful return of the premises' occupants to the repaired facilities.

"Whenever complete cleanup of mould is performed, special attention must be paid to protection of the cleaner, the use of appropriate tools, and the order in which cleanup procedures are carried out. For instance, a vacuum cleaner equipped with a HEPA filter is a must in place of an ordinary vacuum cleaner, and waste resulting from cleaning must be disposed of appropriately. It is important that site cleaning, complete cleanup of mould, and cleaning of the ventilation system be scheduled correctly and reconciled in order to avoid extra work,' Leppänen says.

The mould cleanup guidelines prepared by the Finnish Institute of Occupational Health have been updated and fleshed out fully as part of the Moisture and Mould Programme. Suomen JVT- ja Kuivausliikkeiden Liitto has made its contribution to this work. The updated guidelines for cleanup of mould and cleaning of removable items are available on the Web site presenting material produced by the programme: Talkoissa nikkaroitua (in Finnish only).


Checklist for complete cleanup of mould:

  • Employ professionals to renovate premises with moisture damage, and to handle cleanup of mould.
  • Do not forget to ensure that negative pressurising of the repaired premises, protection, and proper cleaning are included in the invitation to tender.
  • Demand that those performing the repairs wear appropriate protective clothing and equipment and that they prevent mould dust from spreading with the workers.
  • Complete cleanup of mould is the last stage of a renovation project to repair moisture damage.

Repair of moisture and mould damage

In Finland, problems caused by moisture and mould occur in the entire building stock: buildings owned by the central government, local government, and members of the public alike. The owner of each building is responsible for ensuring its health, which means that the owner should prevent the occurrence of moisture damage when the building is designed, built, and used. The programme to combat moisture and mould creates new methods for making the owner's task easier, and for furthering expertise.

Aims include preparing a uniform procedure for investigations to be performed whenever problems in indoor air or with moisture are suspected, and to devise well-functioning repair methods. Plans for project network cooperation include education and training, communication, instructions, and guidelines targeted at property owners and those planning and executing repairs.

In addition to central government, local authorities own a significant number of properties in Finland. In terms of public health, it is extremely important to prioritise the repair of schools, day-care centres, health-care facilities, and other properties with indoor air problems. Therefore, the programme seeks methods for municipalities to enhance competence related to indoor air, and to facilitate the efficient repair of premises with problems.