Case Study: How a Damp Survey Uncovered Damp Cavity Wall Insulation

At CavClear, we help homeowners uncover hidden damp problems before they lead to costly repairs. Recently, we were called out to a property where the homeowners had noticed worrying signs of damp. What started as a routine damp survey quickly uncovered a much bigger issue; extremely damp cavity wall insulation, which had been causing penetrating damp.

Signs of Damp in the Home

The homeowners first noticed damp patches forming on their internal walls, particularly on the lower floors. Over time, these patches grew darker, and they began experiencing condensation and a persistent mouldy smell, causing them to reach out to our team for a professional damp survey.

Damp Cavity Wall Insulation

Using our advanced damp testing equipment, we measured high moisture levels in the affected areas. To identify the root cause, we conducted a borescope inspection, inserting a small camera into the cavity wall. We found cavity wall insulation was completely saturated, acting like a sponge and allowing moisture to penetrate through to the interior walls.

Why Wet Cavity Wall Insulation Causes Damp Issues

Cavity wall insulation is meant to improve energy efficiency, but when exposed to excess moisture, it can do more harm than good. Instead of repelling water, saturated insulation holds onto it, allowing moisture to transfer across the cavity, leading to penetrating damp inside the home. This can cause:

• Persistent damp patches and mould growth
• Damage to plaster, paint, and internal finishes
• A decrease in thermal efficiency, making the home colder and more expensive to heat
• Potential structural damage if left untreated

The Next Steps: Full Cavity Wall Insulation Extraction

After explaining our findings to the homeowners and providing a detailed report, we recommended a full cavity wall insulation extraction to remove the source of the damp. This process involves:

1. Carefully removing sections of external brickwork to access the insulation.
2. Using specialist equipment to extract the wet insulation safely.
3. Cleaning and drying the cavity to prevent further moisture buildup.
4. Assessing the cavity for any necessary repairs before reinstalling a more suitable insulation solution (if needed).

Removing the insulation is essential to prevent further moisture ingress and allow the walls to properly dry out. Without extraction, the damp problem would persist as cavity wall insulation can’t dry out within the cavity, leading to continued deterioration and higher repair costs in the future.

Why Damp Surveys & Insulation Checks Matter

This case highlights the importance of damp surveys and cavity wall inspections when dealing with moisture issues. In many cases, homeowners may not realise that their insulation is contributing to the problem. By identifying and removing the damp insulation, we can improve energy efficiency, and protect the property from long-term damage.

If you’ve noticed signs of damp in your home, don’t ignore them! Book a professional damp survey today and ensure your walls are working as they should. Contact us now to schedule your survey!