Reading Between the Readings

In one recent pre-purchase survey, two of our surveyors, Rosie and Emma, picked up a high damp meter reading on a wall section with no visible staining, discolouration, or other indicators of dampness. It’s easy to dismiss a reading like this with the mindset of, “If it’s not causing a problem, why worry about it?” And, in many cases, isolated high readings are just anomalies - possibly from historic moisture, hygroscopic salts, or even slight sensor interference.

But sometimes, these readings can offer early clues to developing issues.

Without context, high damp meter readings can lead to unnecessary concern and even jeopardise house sales. This is where the knowledge Nova Surveyors can offer can provide clarity, reassurance, and practical solutions - ensuring issues are properly understood, accurately reported, and proportionately addressed. It can also to help protect customers from costly and unnecessary damp-proofing works.

While the immediate concern in this case was the lack of sealant around the door trim - which we recommend addressing as a priority - we also advised that longer-term consideration be given to modifying the raised decking. Specifically, we suggested either lowering the decking level or removing the section directly against the wall to allow for the installation of an ACO drainage channel. This would help divert water away from the base of the wall and reduce the risk of water splashing up and over the damp proof course, particularly during heavy rainfall.

As this measure isn’t urgent, we recommend it as a planned improvement over the next 12 to 24 months. Offering this kind of phased advice helps homeowners and buyers take control of their maintenance priorities and budget accordingly - especially when moving into a new home where there are often multiple demands on time and money.

In this particular case, we widened the scope of our inspection to understand the context. There were no internal signs of damage, and the damp proof course (DPC), where visible, appeared intact. However, a closer external look revealed that decking had been installed above the original ground level, and crucially, it bridged the DPC.

This type of detail is often missed, especially when hidden beneath garden landscaping or outdoor installations. Raised decking can allow moisture to bypass the DPC, creating cold bridging or providing a direct route for wind-driven rain to track over the course into the internal structure.

Interestingly, though, this decking spanned multiple rooms - yet only one showed a high reading. This pointed us toward a more localised defect.

Just beside the area in question, we observed that the UPVC door trim hadn’t been sealed. On exposed, coastal elevations such as where this home was, this kind of gap becomes a direct route for driving rain to bypass protective barriers. Over time, even small openings can let moisture in, especially during windy weather that forces rain horizontally against the structure.

This relatively minor defect - a small gap, easy to fix - was the most likely cause of the damp meter reading. Left unchecked, it could have developed into a longer-term problem, hidden behind kitchen units or under flooring.

The solution in this case was straightforward: a DIY sealant job costing under £10, or professionally done for under £100. While not urgent, the repair was proactive and preventative, demonstrating the value of identifying minor defects before they become significant disrepair issues.

To complete our assessment, and to eliminate other potential sources, we also used a camera pole to inspect the guttering above the affected area - something that can easily be missed when surveying on dry days. A blocked or misaligned gutter could have contributed to concentrated moisture in that location, so it was important to rule it out. 

Damp meters provide a snapshot - but not the whole picture. Without proper context, readings can mislead, either causing unnecessary concern or giving false reassurance. That’s why a holistic approach is essential, blending technical readings with practical, evidence-based reasoning.

Sometimes, the most helpful thing we do during an inspection is to spot the small, simple issues before they turn into major problems. That’s good for our clients, good for the properties, and ultimately, good for the people who live in them.