When it comes to completing a building survey for dampness, there's one element that matters more than anything else: thoroughness.
A survey that is ... surface level and leaves many areas under-investigated is of little use. Not only does it provide an inaccurate representation of dampness in a building or space, but it also leaves the doors open for damp issues to become much bigger and more costly to rectify.
Being thorough isn't strictly about taking as many readings as possible while surveying.
Certainly, there's nothing wrong with an abundance of measurements – in fact, some professionals say the more readings, the better.
However, the key to being thorough and having a complete understanding of damp intrusion is using the right tools for the job. Undoubtedly, that starts and stops with knowing how to use the damp meters in your repertoire.
In completing building damp surveys, your meter options are simple – use a pin-type meter or a pinless (non-invasive) meter, or a dual-function meter (which is a combination of both). Let's take a look at each meter's function and how to best use both.
As their name indicates, pin-type meters use two probes (pins) to determine actual moisture content within a material. Measuring the electrical resistance between its pins, meter readings identify the damp presence as a percentage. When more dampness is present in a material, there's less resistance between the pins as water is conductive, giving a higher reading.
Testing with a pin meter involves simply touching the meter's probes to the surface of the material being tested, waiting a second for a measurement, and recording the reading. For good measure, it's recommended to take several readings to verify results.
Pinless meters, also referred to as "non-penetrating meters," provide a different type of reading.
Unlike a pin-type meter, a pinless meter uses radio frequencies or the capacitance of a material to assess the average dampness within its depth of measurement. Pinless meter readings help confirm the presence of dampness within an area – particularly those that can't be tested with a pin-type meter, such as subflooring covered by linoleum or behind a tiled wall.
Testing with a pinless meter involves putting the meter's contact plate to the area being tested and waiting a few seconds for it to take a reading. Pinless meters typically display readings using a color-coded scale – with a high concentration of dampness coming in red. Dry readings come in green.
Despite their differences in how they quantify and qualify dampness, both damp test meter types work well in tandem, helping a surveyor to complete a thorough investigation.
After completing an initial visual inspection, a pinless meter helps you quickly identify areas of concern that can be investigated further with a pinless meter.
Using both meters together – or a dual-function meter – gives you an accurate and comprehensive overview of the area being inspected. This, in turn, helps the property owner to make informed decisions when it comes to damp-proofing and rectifying any problems found before they get worse. What's more, if an insurance company is involved, the more readings you can provide, the better. The last thing any surveyor wants is to have to redo an inspection to satisfy an insurer.
To our last point about gathering as much information as possible, there are two other devices that provide additional means to take a full assessment of dampness in a space.
Digital hygrometers take damp readings in a different direction.
Unlike a pin-type or pinless meter, which both focus on materials and locating excessive dampness, a hygrometer is used to assess a space's ambient environment. In a sense, a hygrometer provides a 10,000-foot view of dampness in a building.
Measuring relative humidity (Rh), temperature, and dew point, a hygrometer allows surveyors to examine the air inside a space to asses the surfaces that are likely at dewpoint and causing condensation. Suffice it to say, areas with higher hygrometer measurements are more likely to be where dampness is present.
However, even an accurate hygrometer's readings are not enough on their own to confirm a damp issue. Just like measurements taken by a non-invasive meter, a hygrometer's readings merit further investigation.
In a sense, a thermal imaging camera provides a means to conduct a visual inspection for that which cannot be seen by the naked eye.
Displaying a visual representation of temperature differences, a thermal imaging camera highlights areas that require further investigation as it helps to identify damp pockets in a building or material. Outside of a hot water leak, areas affected by excessive dampness appear cooler – or blue – in a thermal camera's display screen.
While a thermal camera's findings are by no means confirmation of damp presence, they do help point your survey in the right direction.
When it comes to using a damp meter, there are certain practices that should be followed and others that should be avoided. These damp meters do's and don'ts are essential for taking readings right the first time:
Regardless of the reason for an investigation – be it a water damage event or a routine inspection – damp surveys are complex and take time.
However, with a complete understanding of the damp meters you'll use, you'll have no problem correctly and thoroughly investigate any potential damp issues in a building.
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