Moisture Testing As Part Of The Inspection Process

Moisture testing is a vital component of a property inspection, and is used to identify moisture ingress, leaking showers, faulty plumbing, and roof leaks.

Our inspectors are extensively trained to identify signs of moisture ingress, potential areas of weather-tightness risk, and carry out moisture testing.

Non-invasive moisture testing is included in all three of our property inspection report packages – Bronze, Silver and Gold, and is carried out using a Trotec T660 moisture meter, in conjunction with a thorough visual inspection of the property.

T660 moisture readings

This meter, sends a di-electric current 40 – 50mm into the wall, and returns readings based on a scale of 0 – 160. It should be noted that moisture readings taken with a non-invasive moisture meter are not percentage based.

Different materials can provide different readings with capacitance meters, and therefore our findings are based on comparative readings taken from known dry areas during the inspection. We are trained to interpret these results and identify ‘false positives’ where practical.

Non-invasive moisture readings are taken on the exterior of the property where the practicality and finish of these materials allow, and throughout the interior of the property.

The numbers displayed on the moisture meter are not included within our building reports due to the potential for being taken or interpreted out of context; however, have been recorded during each property inspection and can be discussed further on request.

Where elevated moisture readings have been recorded during an inspection, these will be noted within the contents of our report.


An invasive moisture test is the only way to determine a percentage of moisture content in timber framing, and this type of testing is not included within our standard report packages but can be included in our Moisture Inspections and Weathertightness Reports.

Invasive moisture testing is undertaken by using a ‘hammer and prong’ meter such as the Trotec T510K invasive moisture meter, which will leave small visible marks and small holes in wall linings after testing. To undertake this type of testing, we require written permission from the current owner of the property due to the minor damage caused to wall linings.

T510 Invasive moisture testing

A common misconception is that moisture content is required to be 18% or less – which is true only for new builds or alterations only at construction stage to be able to line the walls; however, for existing houses that have stood for some time, moisture content in the timber framing should return readings of around between 12 – 14%, and no more than 16%.

No moisture meter will be able to identify dry rot within the walls. Where areas of suspicion have been identified using both non-invasive and invasive methods, the only way to confirm the true extent of damage present, is to remove wall linings and any insulation (if present) to allow a visual inspection of the area.

Whether you’re purchasing your next property, or have concerns over a property you currently own, we can tailor a moisture inspection to fit you or your banks requirements.


Give us a call on 0800 4 TRUTH today to book in or discuss options for your next inspection.



Back to news