Penetrating Damp on External Walls — Causes, Diagnosis and Permanent Fix

If damp patches appear high on the wall, around windows, or only after heavy rain, you're not dealing with rising damp — you're dealing with penetrating damp. It's the second most common wall failure we see on the East Rand and it's often misdiagnosed (and mistreated) as rising damp.

How to tell it apart from rising damp

• Damp patches above 1m — often near roof line, gutters or windows.
• Worse immediately after rain, better in dry weeks.
• No salt tide-mark along the skirting.
• Often shows on one exposed wall (usually west or south facing).

The four usual culprits

• Porous face brick or perished exterior paint letting wind-driven rain soak in.
• Cracked render or hairline cracks around window frames.
• Blocked or overflowing gutters saturating the top of the wall.
• Failed sealant where a balcony slab meets the wall.

The permanent fix

Seal any cracks, clear gutters, then apply Damp Gone Xtreme to the entire external wall face. The silane/siloxane chemistry lets the brick breathe out but blocks liquid water from getting in. Two saturating coats, wet-on-wet, will keep an exposed wall dry for 10+ years. Grab a DIY damp wall kit or book our professional service — R150/m² with a 10-year guarantee.