Call us on 021 910 0850 or send us your details and we will contact you:

Penetrating & Lateral Damp Proofing Services

What is Penetrating and Lateral Damp?

Penetration and lateral damp, is a common form of dampness in buildings. It can occur through walls & roofs, or through openings (e.g. window reveals, light fittings, pipes, cables etc) and through the underground walls of basements and cellars.


Water typically penetrates the outer skin of a building and then appears on the inner walls.

Common Defects Include:

• Roof defects such as faulty flashing, cracked or missing slates or tiles.
• Faults in the brickwork or masonry such as missing or cracked pointing.
• Porous bricks or stone.
• Missing or defective sealing around windows frames and doors.
• Blocked weather facing or even non- existent weep holes.
• Missing or defective DPC in cavity walls.
• Structural cracks, corroded spalling and unsealed expansion joints.
• Poor painting and unsealed parapets.

Penetrating damp is most often associated with single-skin walls, but can also occur through cavity walls such as tracking across wall ties.

What Causes Penetrating and Lateral Damp?

• Cracks in render and masonry provide a pathway for damp to penetrate.
• The primary cause of rain penetration through walls is defects in the masonry such as porous masonry (i.e. under-fired bricks, porous stone, or porous mortar).
• Defective pointing.
• Unfilled joints and perpends.
• Defective seals around doors and windows.
• Holes in walls – e.g. where cables or pipes protrude.
• Defective render.
• Broken down flashing and untreated parapets.

Our Treatment Explained

On the inside, the resultant hydroscopic damp needs to be treated by removing the contaminated plaster, the underlying brick work sealed with a waterproof sealant and quartz cream injections done to prevent rising damp if required. The wall is then re-plastered with a salt retarding mortar.