Lifting carpet to check for mould is not always practical, and in some cases disturbing it can make things worse by releasing spores into the air. The good news is that there are reliable ways to detect mould under carpet without pulling it up. Our professional water damage drying service uses moisture meters and thermal imaging to locate hidden dampness and mould without unnecessary disruption to your flooring.
Why Mould Hides Under Carpet
Carpet acts as an insulating layer that traps moisture underneath. When water soaks through the pile and into the underlay, the top surface can dry out while the underlay and subfloor remain wet for days or even weeks. This creates a warm, dark, moist environment where mould thrives. Because the carpet surface looks and feels dry, homeowners often do not realise mould is growing beneath until symptoms appear.
Signs of Mould Under Carpet Without Lifting It
The Smell Test
The most reliable indicator of mould under carpet is smell. Mould produces microbial volatile organic compounds (mVOCs) that have a distinctive musty, earthy odour. This smell is often described as similar to damp soil or rotting wood. If you notice a persistent musty smell in a room that does not improve when you open windows, mould is likely present. Crouch down close to the carpet surface and smell it directly. The odour will be noticeably stronger at floor level.
Visual Checks at Carpet Edges
Check the edges of the carpet where it meets skirting boards and in corners. Mould often appears first at carpet edges where moisture collects and airflow is limited. Look for dark discolouration, black or green spots, or a fuzzy texture on the carpet backing that is visible from the side. Lift the edge of the carpet slightly with a flat tool without disturbing the main area to check the underlay colour without fully removing it.
Health Symptoms at Home
If people in your household are experiencing unexplained allergic symptoms such as sneezing, itchy eyes, a runny nose, or worsening asthma that improves when they are away from the property, mould exposure is a likely cause. Pay attention to whether symptoms improve on weekends away or holidays, as this pattern strongly suggests an indoor air quality problem linked to mould.
Moisture Meter Readings
A moisture meter pressed against the carpet surface gives a reading of the moisture content beneath. Professional-grade moisture meters can detect elevated moisture levels through carpet and underlay without lifting anything. Readings above the dry standard for your carpet type indicate trapped moisture and a high probability of mould growth. This is a standard tool used by professional restoration technicians during assessments.
Thermal Imaging
Thermal imaging cameras detect temperature differences across surfaces. Wet areas under carpet retain moisture and appear as cooler zones on a thermal image compared to surrounding dry areas. This technology allows technicians to map the full extent of water damage without removing any flooring. It is particularly effective for identifying water intrusion paths from leaks that are not immediately obvious.
History of Water Events
Consider whether the property has experienced any water events in the past. A flooding incident, a burst pipe, a roof leak, or even a washing machine overflow can cause mould to develop under carpet if the water was not professionally extracted and dried at the time. If any of these events occurred and the carpet was simply blotted and left to dry naturally, there is a high probability of mould being present in the underlay or subfloor.
What to Do If You Suspect Mould
If your checks suggest mould is present, avoid disturbing the carpet. Do not vacuum the area, as vacuuming can spread spores throughout the home. Call a certified mould and water damage specialist for a professional assessment. They will use moisture meters and thermal imaging to confirm the presence and extent of mould and advise on the correct remediation approach.
When to Lift the Carpet
Carpet should only be lifted by a professional wearing appropriate personal protective equipment. If mould is confirmed, containment protocols should be in place before any flooring is removed. Lifting carpet without these precautions spreads spores to areas of the home that were previously unaffected and creates a much larger remediation job.
Not Sure If You Have Mould Under Your Carpet?
Our certified technicians use moisture meters and thermal imaging to find it without disturbing your flooring. Get a professional assessment before it becomes a bigger problem.
