A damp proof course (DPC) is an essential element in any building to prevent moisture from rising through walls and causing structural damage. Traditionally, materials like brick or bitumen have been used as DPCs, but there has been some speculation about whether roofing felt can serve the same purpose. In this article, we will explore the potential of roofing felt as a damp proof course and evaluate its effectiveness.
Understanding Damp Proof Course
Before we delve into the possibility of using roofing felt as a DPC, it is important to understand what a DPC is and its role in preventing dampness. A DPC acts as a barrier between the ground and the structure, preventing water from seeping through and causing dampness in walls. It is typically installed horizontally in the base of a building, such as the wall/floor junction or beneath the ground floor slab.
Traditional DPC Materials
Bricks and bitumen have long been used as traditional DPC materials due to their impermeability to water. Brick DPCs involve laying a course of engineering bricks in a mortar bed, creating a solid barrier. Bitumen DPCs consist of a layer of bitumen felt or other bitumen-based material, which is also highly resistant to moisture penetration.
Roofing Felt as a DPC
Roofing felt is a common material used for waterproofing roofs and has some qualities that make it a potential candidate for a DPC. While roofing felt may not be specifically designed as a DPC material, it shares some similarities with traditional DPC materials in terms of its water-resistant nature.
Properties of Roofing Felt
Roofing felt is typically made from a combination of asphalt and cellulose fibers, which makes it highly water-resistant. It is applied in multiple layers, with each layer bonded together to create a barrier against water penetration. The thickness of roofing felt can vary, with thicker felt generally providing better waterproofing properties.
Potential Advantages
Using roofing felt as a DPC does offer some potential advantages. Firstly, it is easily accessible and widely available, making it a cost-effective option compared to traditional DPC materials. Additionally, roofing felt’s water-resistant properties make it a suitable candidate for preventing rising damp. It can be easily installed, either as a standalone barrier or in conjunction with other DPC materials.
Potential Drawbacks
While roofing felt may have some benefits, there are also potential drawbacks to consider. Firstly, roofing felt is primarily designed for vertical applications and may not perform as efficiently when used horizontally as a DPC. The material is more susceptible to damage and degradation over time, potentially reducing its effectiveness as a long-term solution. Additionally, roofing felt may not provide the same level of protection against water penetration as traditional DPC materials like bricks or bitumen.
Roofing felt has some qualities that make it a potential candidate for use as a damp proof course. Its water-resistant properties and cost-effectiveness make it an attractive option. However, its effectiveness may be limited due to its design for vertical applications and potential degradation over time. It is advisable to consult with professionals and consider alternative traditional DPC materials, such as bricks or bitumen, to ensure the best long-term protection against rising damp.