Mr Ikechukwu Godwin, a construction expert, has identified misdiagnosis of damp, overwhelmed damp-proof courses and trapped salts as major causes of moisture in buildings.
He warned that surface repairs treat only the symptoms, not the hidden source of moisture.
Godwin, who spoke to reporters in Suleja on Sunday, said homeowners should not treat damp walls as merely a cosmetic problem.
“Homeowners often treat peeling paint and mould as cosmetic problems — scraping, puttying and repainting — while moisture continues to travel invisibly through masonry, finding its way back through new paint when the root cause is ignored.”
He said common reasons damp returns include misdiagnosing its cause.
“Treating condensation from poor ventilation or penetrating damp from cracked outer walls, defective render or leaking gutters as rising groundwater from the foundation will always fail.”
He added that a properly installed damp-proof course (DPC) only stops moisture from rising through the walls from the ground.
“An active pipe leak or an unsealed external defect pouring water into the wall above or beside the treatment can overwhelm the barrier.”
Godwin said applying fresh plaster or paint before a wall has dried traps residual moisture inside, which eventually forces its way out.
To address the problem, he advised homeowners to inspect the DPC to ensure it was properly installed and to correct drainage issues. This, he said, would direct rainwater away from the building rather than allow it to collect around the foundation.
He also recommended repairing cracks, defective render and other identified points where water could enter.
Where necessary, he advised removing severely damaged, salt-contaminated plaster and allowing the wall to dry.
“Replastering and repainting should be done with suitable, breathable, moisture-resistant materials only after addressing the moisture source and allowing adequate drying.
“The key is to find and fix the source of the water before repairing the surface; otherwise, the damp will always come back,” he said.
