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What is A Rising Damp?

Rising damp is a phenomenon where moisture moves up from the ground into the walls of a building through a process called capillary action, often leaving visible damage and a musty smell. This can occur in older buildings lacking a damp-proof course (DPC), which is designed to prevent such moisture migration.

Rising damp is relatively rare and should be correctly diagnosed by a professional before treatment is attempted, as it can often be confused with other types of dampness like condensation or penetrating damp.

The signs of rising damp include tide marks caused by salts on the walls, damp and stained wall coverings, peeling wallpaper, blistering paint, and decaying timber such as skirting boards and floor joists. Over time, rising damp can lead to structural damage in buildings and contribute to higher energy bills due to increased heat loss.

Diagnosis involves identifying the moisture source and understanding the building’s structure, including the effectiveness of any existing damp-proof course. Traditional methods for addressing rising damp include installing a new DPC using physical barriers or chemical injections. More modern approaches focus on managing the moisture through ventilation and using materials that allow walls to breathe, which can prevent the trapping of moisture and the resultant damage.

Here are more detailed descriptions of the three common treatments for rising damp:

1. Damp-Proof Injection

What It Is: Damp-proof injection involves drilling holes into the affected walls at regular intervals just above ground level. These holes are then filled with a water-repellent cream or fluid. This substance is designed to spread throughout the brickwork or masonry, creating a barrier that prevents moisture from rising up through the wall.

Pros:

  • Quick and easy to apply, causing minimal disruption to the household.
  • Cost-effective, especially when compared to more invasive methods.
  • Effective in a variety of settings, suitable for both residential and commercial properties.

Cons:

  • Dependency on correct application, as improper installation can lead to ineffective damp proofing.
  • May not be suitable for all wall types, particularly those with highly porous or irregular materials where the cream might not distribute evenly.
  • Temporary solution, may require re-application after some years depending on the severity of damp and environmental conditions​.

2. Horizontal Wall Cutting

What It Is: This method involves cutting a horizontal trench through the entire thickness of the wall, from both sides. A new damp-proof course, typically made from a synthetic material, is then inserted into this trench to block any moisture from rising above this barrier.

Pros:

  • Permanent solution, providing long-lasting protection against rising damp.
  • Comprehensive protection, as the barrier extends the full width of the wall.

Cons:

  • Highly invasive, requiring significant structural work that can be disruptive.
  • Expensive, due to the complexity of the work and the need for professional execution.
  • Necessitates subsequent repairs, such as replastering and redecorating the affected areas​.

3. Carebrick Damp Treatment

What It Is: The Carebrick system involves inserting specially designed ceramic tubes into the walls. These tubes create a thermal bridge, which draws moisture out of the wall. The moisture is then vented away naturally, reducing the damp within the wall structure.

Pros:

  • Innovative technology, offering a unique approach to damp treatment that can also improve thermal efficiency.
  • Less invasive than cutting, as it involves only drilling small holes for the ceramic tubes.
  • Works continuously, pulling moisture out of the walls over time.

Cons:

  • Relatively new method, which may not have as much long-term data on effectiveness compared to more traditional methods.
  • Potentially higher initial cost, although it can lead to savings in heating and maintenance in the long run.
  • Installation dependent, as improper placement of the tubes can render the system ineffective​​.

Each of these treatments has its own specific approach and suitability depending on the structure of the building and the severity of the damp problem. It is crucial to consult with a specialist who can recommend the best solution tailored to your building’s needs.

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