Penetrating Damp

What is Penetrating Damp?

Rain penetration through masonry (known as penetrating damp) is a common problem in buildings – particularly in the case of those of solid wall construction. The problem is also increasingly common in buildings of cavity wall construction where cavity wall insulation has been poorly installed or used in walls that are not suitable for cavity wall insulation. Other paths through which rain can cross through a cavity wall include incorrectly positioned wall ties and mortar obstructions in the cavity.

Symptoms of Penetrating Damp

Older buildings, especially with solid walls, are more likely to suffer from penetrating damp. Be aware that the symptoms can often take weeks or months to appear. There are a number of symptoms to look out for when identifying penetrating damp:

localised-dampness Localised dampness — Blotchy patches on internal walls.
plaster-damage Plaster damage — Plaster & paint deterioration, blistering, appearance of stains & salts.
wet-rot Wet Rot — Rotting skirting boards or timber.
mould Mould — Mouldy smell or signs of mould growth on internal decoration.
mossy-wall Moss — Excessive moss growth on external walls.
spalled-brick Brick damage — Moisture entering the brick (known as spalling) causes surface damage.

Causes of Penetrating Damp

Penetrating damp is caused by water permeating through walls from the outside. It can occur at all levels of a building but is more prevalent higher up. It is possible for damp to move within walls but this horizontal movement differs from the vertical movement of rising damp. Penetrating damp is usually caused by the following:

Porous Walls — Aging bricks lose the ability to keep out rain penetration.
Spalled Bricks & Degraded Mortar — Damage to brickwork allows water to penetrate.
Building Defects — Defective guttering and downpipes, roof damage, dilapidated or poorly installed windows. In this case fix the root of the problem before applying Aquadry to boost your protection.

Treatment with Aquadry

Aquadry Masonry Protection Cream and Aquadry Repointing Additive can be used to provide protection against penetrating damp without affecting the visual appearance of brickwork or stonework.