Victorian-era buildings commonly employed several types of materials for damp-proof courses (DPCs) to prevent rising damp. These materials were typically chosen for their ability to create a barrier against moisture rising up through the walls via capillary action. Some of the common types of DPC used during the Victorian era include:
Bitumen felt: This was one of the earliest materials used for DPCs. Bitumen felt is a waterproofing material made from layers of organic or synthetic fibres impregnated with bitumen (a type of asphalt). It was typically laid horizontally at the base of the wall during construction to create a barrier against rising dampness.
Slate: Thin slates or slate damp-proof courses were also commonly used in Victorian buildings. Slates were laid horizontally at the base of the wall to create a barrier against moisture penetration.
Engineering bricks: These are dense, impermeable bricks specifically designed for use in damp-proof courses and other applications requiring resistance to moisture. They were often laid in mortar beds at the base of the wall to create an effective barrier against rising dampness.
Lead or copper sheeting: In some cases, lead or copper sheeting was used as a DPC. These materials were durable and resistant to corrosion, making them suitable for long-term moisture prevention.
Terracotta or ceramic damp-proof courses: These were also used in Victorian buildings, particularly in areas where there was a risk of dampness. Terracotta or ceramic damp-proof courses were laid horizontally at the base of the wall to create a barrier against rising dampness.
These traditional materials were chosen for their effectiveness in preventing moisture from rising through the walls and causing dampness in Victorian-era buildings. While modern damp-proofing methods may have evolved, these traditional materials continue to be found in many historic structures and can still be effective when properly installed and maintained.
Common modern damp-proofing methods
Rising dampness is a common problem in buildings, particularly in older structures with poor damp-proofing measures. Traditional methods for preventing rising dampness typically involve a combination of techniques aimed at blocking moisture from moving upward through walls. Here are some efficient traditional methods:
Damp-proof courses (DPC): This is a horizontal barrier typically made of materials like bitumen felt, engineering bricks, or plastic membranes. It’s installed at the base of the wall during construction to prevent moisture from rising up through capillary action and has a limited life.
Chemical Damp-proofing: This involves injecting a chemical damp-proofing solution into the masonry to create a barrier against rising moisture. Common chemicals used include silicone-based solutions or creams that are injected into holes drilled into the wall. The solution needs to be applied to the mortar layer and has very mixed results especially when used with modern insulated bricks.
Rendering and plastering: Applying a waterproof rendering or plaster to the affected walls can help prevent moisture from penetrating into the building. Lime plaster, for example, was often used traditionally due to its breathable and moisture-regulating properties. However, products used to block the dampness like resin, and resin-based plasters just move the issue to another location over time.
Improving drainage: Ensuring proper drainage around the building, such as installing guttering and downpipes, and ensuring the ground slopes away from the building can help prevent water from pooling around the foundation and exacerbating rising dampness. Clay soils often need extensive groundwork to ensure water moves and the foundation will always remain in contact with the water.
Ventilation: Good ventilation is crucial in preventing moisture buildup inside buildings. Installing airbricks or vents in the walls allows air to circulate, helping to dry out damp areas and prevent condensation. However, this often fails on insulated buildings and heated buildings.Â
Repairing structural defects: Cracks, gaps, and defects in walls can allow moisture to penetrate.
Using breathable materials: Using breathable materials in construction, such as lime mortar and natural stone, can help regulate moisture levels in the building and prevent dampness.
Regular maintenance: Regular inspections and maintenance can help identify and address any issues early, preventing them from developing into more significant problems. Repairing damaged on non-existent DPC is often not possible without rebuilding walls.
These methods, when applied properly and in combination, can help in reducing rising dampness in traditional buildings. However, it’s essential to assess each situation individually and consider the specific factors contributing to dampness before deciding on the appropriate solution.
Natural modern alternative
Diathonite is a brand of natural thermal plaster produced by Diasen, an Italian company. Diathonite is designed to provide various benefits to buildings, including helping to prevent dampness. Here’s how Diathonite helps in preventing dampness:
Natural composition: Diathonite is made from natural materials such as cork, lime, and diatomaceous earth. These materials have inherent properties that help regulate moisture levels. Cork, for example, is hydrophobic, meaning it repels water, while lime has breathable properties that allow moisture to evaporate.
Breathability: Diathonite is highly breathable, allowing water vapour to pass through it. This breathability helps to regulate humidity levels within the building, reducing the risk of condensation and mould growth, which are common problems associated with dampness.
Hygroscopic properties: Diathonite has hygroscopic properties, meaning it can absorb and release moisture from the surrounding environment. This helps to stabilize humidity levels within the building, reducing the likelihood of dampness occurring.
Thermal insulation: Diathonite provides thermal insulation to buildings, helping to maintain a stable indoor temperature. By reducing temperature fluctuations, Diathonite can help minimize the risk of condensation forming on cold surfaces, which can contribute to dampness.
Moderate Crack resistance: Diathonite is applied as a plaster, providing a seamless finish to walls and ceilings. This reduces the likelihood of cracks forming, which can provide pathways for moisture ingress and contribute to dampness.
Longevity: Diathonite is a durable material that can provide long-lasting protection against dampness when properly applied. Its natural composition means it is less prone to degradation over time compared to synthetic materials.
Overall, Diathonite helps prevent dampness in buildings by regulating humidity levels, providing thermal insulation, and creating a breathable and durable barrier against moisture and salt ingress. It’s particularly beneficial in older buildings or those located in damp-prone areas where traditional damp-proofing was insufficient.
There is no magic bullet to treating dampness, however, Diasen Diathonite has become one of Europe’s most respected insulating products for historic buildings in recent years amongst professionals.
