Penetrating Damp takes place when defective roofing, brickwork, windows, high ground levels etc. allows for water to penetrate to the inside fabric of your house.
Defects to the outside construction of the building works: weak roofing, ingress of water through uncapped chimneys, especially unvented blocked chimney breasts. chipped render & brickwork, clogged or damaged guttering, broken & corroded downpipes, badly fitting or rotten door frames & windows, all of which allows for rain water to penetrate into the fabric of the building.
Identifying Penetrating Damp
Indications to search for when attempting to determine if the cause of problems is penetrating damp include; Discolouration of the inner decor with the presence of tide marks, salt deposits. Blown/blistered (hollow sounding) plaster. Wet and/or rotting skirting boards quite often exhibiting corroding nails, similar to floor timbers. Random damp patches to any elevation on the walls and ceilings. Dark mold on inside walls, window frames etc.