Conducting the site inspection

The site inspection clarifies whether and to what extent there is mould infestation and determines the possible causes (see Chapter 3). Impor-tant building physics parameters such as room temperature, indoor air humidity, material moisture and surface temperature are collected as well as constructional boundary conditions, information on the af-fected space and its use and possible building-independent sources of mould (e.g. biowaste, animals kept in cages, terrariums). The DIN EN ISO 16000-32 (2014) “Examination of buildings for pollutants” provides val-uable information.

An important indicator of mould infestation are odours that are typical of mould and indicate moisture. The site inspection also provides the possibility to localise odour sources. Any odour determination should be based on the relevant guidelines (AGÖF Guidelines for Odour, DIN ISO 16000-30 “Odour Test of Indoor Air” and VDI 4302 Sheets 1 and 2

“Odour test of indoor air and emissions from indoor materials”).

Building physics and room climate investigations can be used to de-termine whether the effects of use or construction are at the root of in-creased humidity and mould growth (see Chapter 3).

The aim of site inspection ist to collect and record physics data (e.g. temperature, humiditiy) and general information about the affected rooms in an inspection report. Interviewing the room oc-cupants regarding the type of room use and their perception of the indoor situation also serves the purpose.

The site inspection should also carry out an optical and sensory evaluation of the affected rooms and of the materials an objects in the rooms.

The aim of the site inspection ist to clarify whether mould infesta-tion is present and to what extent.

This information establishes whether an, if so, what additional further investigations are required for clarification.

Further measurements are generally not required if the mould in-festation is visible (Category 2 and 3, see Table 8) and has a clar-ified cause. However, the affected area should be remediated in a timely manner under consideration of the utilisation class.

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Climate records (temperature and relative humidity) using data log-gers have proven to be very useful in facilitating the evaluation of the different influences on the emergence of infestations. These measure-ments are usually useful in the cold season and should take place in important areas (assumed cool surfaces, indoor air, possibly outdoor air). Since the results of individual measurements are subject to strong fluctuation, long-term measurements over several weeks (e.g. using data loggers) are best suited to provide useful results, and they also can characterise ventilation behaviour. This helps identify whether and over what periods or in which activities critical constellations of tem-perature and humidity may occur.

In addition, building physics investigations (e.g. room-side building thermography or airtightness tests) can also be applied. Room-side ther-mography is a non-contact measurement of the surface temperature that reveals temperature differences and may indicate thermal bridges or moisture in the building materials. A site inspection can provide adhe-sive film samples from areas of microbial infestation and examine them for active infestation (mycelium growth/sporophors) at short notice.

Since building thermography can be influenced by many factors (e.g. ma-terial properties, construction method, weather conditions, solar radia-tion, furnishings), taking and evaluating the records is the responsibility of experienced specialists.

Thermography reveals differences in the temperature of compo-nent surfaces in the form of a colour pattern. Room-side ther-mography enables the clarification of thermal bridges and damp areas and can therefore also be used to locate problem areas for mould growth (cooler areas).

Mould often finds optimal growth conditions behind pieces of furniture next to exterior walls because the circulation of warm air is prevented and a significantly increased surface moisture is possible because of the cool walls.

That is why indoor site inspections should also check for mould growth behind shelves, cupboards and upholstered furniture, especially if the furniture is close to cool exterior walls (see explanations in Sections 3.1.3 and 3.1.4). If possible, separated cavities, storage spaces and parti-tioned areas – especially in occupied attics – should also be inspected.

In the case of water damage in lightweight constructions, interspaces in the construction (behind gypsum plasterboard) must also be opened and checked.

During the site inspection, the expert should also collect relevant infor-mation about the indoor space regarding mould infestation in addition to the building physics parameters (see also DIN EN ISO 16000-19). The

collection of general information on the indoor space and its use as well as any known sources of mould is indispensable for a clear interpretation of the measurement results about mould infestation in the indoor space (see Section 5.2) and, if applicable, for the remediation of mould infesta-tion (see Chapter 6).

The following are examples of important information in the inspection report:

Indoor space

▸ General information (location and size, age of the building,structural features, wet rooms, building materials, basement, attic, insulation, type of windows)

▸ Indoor features (floors, walls, furniture, cur-tains, pot plants, air humidifiers)

▸Building ventilation systems

▸Heating system

▸Type of room use

▸Number of occupants

▸Heating and ventilation behaviour

▸Thermal insulation measures

▸Odour: type and intensity

Indications of mould infestation and/or moisture damage in the indoor space

▸ Visible mould infestation, damp patches and other moisture damage

▸ Earlier or current occurrence of moisture and/

or mould problems (including measures taken so far)

▸Water damage, heating leaks

▸ Materials with moisture damage (e.g. masonry, furniture, insulation materials, books)

▸Building measures with moisture input Other possible mould or moisture sources in the indoor space:

▸ Biowaste collection or ‘green dot waste’ bin in the indoor space

▸Potting soil of indoor plants

▸Pets kept in cages

▸Greenhouse in connection with the indoor space

▸Air humidifier, indoor water fountain

▸Aquarium in the indoor space

▸Damp firewood

Possible mould sources in the surrounding area

▸ Emitting operations in the area such as compost plants, garden centres

▸ Recyclable material sorting plants, agricultural facilities

▸Biowaste bins, compost heaps

It is reasonable to record this information in a standardised inspection report which contains all information, including any photographic doc-umentation. Such an inspection report serves as a checklist for the site inspection and should facilitate a comparable and comprehensible docu-mentation. For laboratory investigations, all data must be included to al-low unambiguous assignment and characterisation of the samples (sam-pling record). When creating the inspection report, it should be borne in mind that it may serve as a reference document for other experts (e.g. ar-chitects, environmental epidemiologists). Comprehensibility and trans-parency are therefore key issues.

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The results of the site inspection show the direction of further proce-dures. In many cases, the site inspection has already provided specific recommendations for remediation measures without further investiga-tion being needed. Further measurements are unnecessary particularly when mould infestation can clearly be recognised visually and the cause of damage identified. Rather, prompt remediation steps should be taken (see Chapter 6). Adhesive film samples (see Section 5.1.2.1) may provide evidence that the issue is mould infestation indeed.

Further investigations are necessary if the site inspection and build-ing physics investigations cannot clearly determine if there is a mould problem or where the mould infestation is precisely located (see Sec-tion 5.1.2).