Damp proofing relies on several materials to prevent moisture from entering a building. These materials are chosen based on the application and the level of protection required.
Common Damp Proofing Materials
Damp proofing materials broadly fall into two categories: flexible and semi-rigid.
Flexible Materials
- Bitumen Felts: These are widely used and come in various types, including those with a hessian or fiber/glass fiber base. Bitumen is a waterproof, tar-like substance. This material is often used as a damp-proof course (DPC) in walls and floors.
- Plastic Sheeting (Polythene Sheets): A more economical option, although generally less durable than bitumen felts, polythene sheets provide a barrier against moisture. These are often used in simpler applications or as a supplementary layer.
Semi-Rigid Materials
- Mastic Asphalt: This is a durable, waterproof material applied as a thick layer. It offers excellent protection and is suitable for demanding applications.
- Combined Materials or Layers: Often, a combination of materials is employed for enhanced damp proofing. For example, a DPC membrane may be combined with a waterproof render.
Choosing the Right Material
The selection of damp proofing material depends on several factors, including the type of construction, the level of moisture expected, and the budget. For critical areas, durable and high-performance materials like mastic asphalt are preferred. In less critical areas, more economical options such as polythene sheets might suffice.
