What Equipment Is Used During a Damp Survey?
When arranging a damp survey, it is natural to wonder what equipment a surveyor will use and what the different readings actually tell you. Modern surveying equipment can provide useful information about possible moisture, humidity, temperature, air movement and salt analysis. However, no single piece of equipment can diagnose the cause of a damp or moisture-related problem on its own.
At Surveying Damp Limited, equipment is used alongside a visual inspection and an understanding of the property's construction, condition and the location and pattern of any defects. The aim is to build a picture of what is happening rather than simply record that a wall has a "high" reading.
Electronic Moisture Meter
Electronic Moisture Meter
Electronic Moisture Meter
An electronic moisture meter, commonly referred to as a damp meter, is one of the most commonly used tools during a damp survey. These meters can provide useful readings and help identify differences between affected and apparently unaffected areas. However, many commonly used electronic moisture meters work by detecting electrical conductivity. Readings can therefore be influenced by factors other than moisture, including salts, the type of material being tested and other conditions within the building. A reading should therefore not be relied upon on its own to diagnose damp or establish a particular cause, such as rising damp. Where unusual or elevated readings are identified, they will usually indicate that further investigation and interpretation is required alongside the visual evidence and other findings. Where appropriate, additional testing such as salt analysis may also be considered.
Salt Analysis
Electronic Moisture Meter
Electronic Moisture Meter
A salt analysis test kit can be used where further investigation of a moisture-related defect is considered appropriate.
The testing can provide an indication of certain soluble salts present within a building material, including chlorides and nitrates. The presence and concentration of these salts can provide additional information when assessing possible sources of moisture. Salt analysis can be particularly useful where there is uncertainty about the history or source of moisture within a wall. However, the results should not be considered in isolation and need to be interpreted alongside the building construction, location and pattern of the defect, moisture readings and other evidence gathered during the survey. Where results are inconclusive, further investigation or more detailed laboratory analysis may be appropriate.
Hygrometer
Electronic Moisture Meter
Thermal Imaging Camera
A hygrometer measures air temperature, relative humidity and surface temperature readings. This can be particularly useful when investigating condensation and mould, where the amount of moisture within the indoor air and the conditions within the property can be important. Humidity readings can help provide a better understanding of the internal environment and whether factors such as ventilation, heating and moisture production may be contributing to condensation or damp within a home.
Thermal Imaging Camera
Thermal Imaging Camera
Thermal Imaging Camera
A thermal imaging camera shows differences in surface temperature. During a damp survey, this can help identify areas such as cold spots, thermal bridging, changes around openings, heating patterns or other areas that may warrant closer investigation. Thermal imaging does not directly measure moisture and does not "see damp". Images need to be interpreted alongside the visual inspection, moisture readings, building construction and prevailing conditions. The thermal imaging equipment used during a standard damp survey is intended as a supporting investigative tool. Where a detailed thermographic inspection of an entire property or more advanced thermal analysis is required, a specialist thermographer with more advanced equipment may be appropriate.
Anemometer
Thermal Imaging Camera
Anemometer
An anemometer measures air movement and can provide useful information when investigating ventilation and condensation-related issues. For example, it can be used to check for measurable airflow at an extractor fan or ventilation opening and provide additional information about how air is moving within the property. Airflow readings are only one part of the assessment and do not, on their own, establish whether a ventilation system is adequate. The handheld equipment used during a standard damp survey is intended to provide indicative information about air movement, rather than constitute a formal ventilation performance or Building Regulations Part F compliance assessment.
How Is the Equipment Used Together?
The most useful information usually comes from combining different types of evidence. For example, a moisture meter may identify an area requiring further investigation, salt analysis may provide additional information about soluble salts, a thermal imaging camera may highlight a temperature difference, a hygrometer may show the humidity conditions, and an anemometer may provide information about air movement.
These findings can then be considered alongside the visual appearance, location and pattern of the defect, as well as the construction and condition of the property. By bringing this information together, it may be possible to identify or rule out potential sources of moisture ingress and establish the most likely cause of the problem, helping to determine what, if any, remedial work may be appropriate.
Does Every Damp Survey Need All This Equipment?
Not necessarily. The equipment used will depend on the property, the concerns raised and what is found during the inspection. A straightforward issue may not require every instrument, while a more complex issue may benefit from several different measurements or tests. The purpose of using equipment is not simply to make a survey appear more technical. It is to gather useful evidence that can help support a reasoned conclusion.
What Equipment Cannot Tell You
All surveying equipment has limitations. Where the available evidence is not sufficient to establish the cause, further investigation may be recommended rather than making an unsupported diagnosis.
Ultimately, the equipment is there to support the surveyor's observations and provide additional evidence. By considering the information gathered alongside the visual inspection and the property itself, the aim is to reach a reasoned assessment of the most likely cause and determine whether any further investigation or remedial work may be appropriate.
The tools used should supports the surveyor's assessment; it does not replace it.