Damp proofing - Penetrating damp

Penetrating damp (sometimes called lateral damp) occurs when water leaks through walls, usually from rainwater but it can also arise from perpetually leaking overflow pipes and other external sources.  Causes of penetrating damp include:-

• Broken or damaged guttering and or downpipes
• Porous or damaged brickwork
• Cracks in external walls
• Poorly directed rainwater run-offs from garages & extensions
• Bridged wall cavities

Damp proofing – Any of these factors left unaddressed can result in evidence of damp on internal walls and can look very similar to other forms of damp – damaged plaster & paint work, black mould growth, crystalline deposits etc.  In some cases, water ingress through external walls may not be evident directly inside the property as water will run down the cavity and may pool elsewhere and can be misdiagnosed as rising damp.  Usually though, evidence of penetrating damp will be at or close to the cause, often in the top corners of rooms.