13/08/2026
Removing failed cavity wall insulation.
Failed or poorly installed cavity wall insulation can contribute to serious damp and moisture problems. In particular, when mineral wool insulation becomes saturated with water, it can create a pathway for moisture to transfer from the external wall towards the internal wall.
Signs of a potential problem can include:
Damp patches appearing on internal walls
Mould and mildew
Peeling or blown plaster and paint
Cold spots on walls
Musty smells
Increased humidity inside the property
Damp becoming worse after periods of heavy rain
Mineral wool cavity insulation can perform well when correctly specified and installed in a suitable wall. However, if the cavity is unsuitable, the installation is defective, or water is entering the cavity, moisture problems can occur. Government guidance confirms that genuine problems can arise from faulty cavity wall insulation installations.
If you suspect your cavity wall insulation has failed, don't simply treat the symptoms. The cavity should be properly inspected to establish whether the insulation is wet, bridging the cavity or allowing moisture to reach the inner leaf.
In some cases, professional cavity wall insulation extraction may be required, followed by repairs to any underlying defects that are allowing water into the cavity.
Wet insulation? Damp walls? Mould problems?
A proper inspection can help identify the cause and determine the most appropriate solution before further damage occurs
