Penetrating damp (lateral damp) is the horizontal ingress of moisture through the building walls. It is often caused by porous walls, damaged brick work and building/structural defects. Defective guttering and down-pipes, roof damage, dilapidated or poorly installed windows and doors all contribute to the ingress of moisture causing penetrating damp. Call us now for an assessment. Office: 021 782 0621 Click Here to send and e-mail Penetrating damp normally occurs on external walls where the external ground levels are higher than the internal floor levels. As a result dampness within the soil bears against these walls and penetrates through them. Consequently, this type of damp is particularly prevalent in basements and cellars, and in the vicinity of structural retaining walls. Penetrating damp will be evidenced on walls by the discoloration of paint, blistering paint, and also the formation of efflorescence on the surface of the walls.