How to Do Foundation Waterproofing?

For buildings to be long-lasting and robust, it is vital to protect the foundation from external factors such as water and moisture. In particular, water that can seep into the foundation due to rising groundwater, precipitation, or environmental factors can damage the integrity of the building. Therefore, foundation waterproofing is one of the most important construction processes for buildings. 

Neglecting foundation waterproofing can lead to serious costs by weakening the durability of the structure. So, how is foundation waterproofing done in buildings, and which methods are used? In this blog post, we prepared as Haydar Boz, we will discuss the different stages of foundation waterproofing, the materials used, and the application methods.

Importance of Foundation Waterproofing

Waterproof thermal insulation coating applied on foundation for protection

The foundation of a building is the most critical part of the building's structural system. The foundation may be continuously exposed to water due to groundwater, ground moisture, and external factors. If no effective measures are taken against this water, the water that penetrates the concrete over time can cause corrosion of the reinforcement, and cracks in the concrete and eventually reduce the structural durability of the building. 

Therefore, foundation waterproofing is a must-do step during building construction. When foundation waterproofing is done correctly, the life of the building is extended and its safety against water is ensured.

Membrane application in the foundation is one of the most common and effective methods of foundation waterproofing. In this application, the outer surface of the foundation is covered using special water and moisture-resistant membranes. Foundation membrane application aims to completely cover the outer surface to prevent water infiltration into the foundation. 

Bituminous membranes are generally preferred because these materials are waterproof and long-lasting. In addition, thanks to their elastic structure, they are not affected by building movements and do not lose their waterproofing performance.

How is Foundation Waterproofing Done?

Black plastic drainage membrane installed on foundation wall for waterproofing

Improperly applied waterproofing can lead to serious problems such as foundation rot, concrete damage, and structural problems. Here is a guide on how you can do foundation waterproofing in detail:

1. Preparation and Planning

  • Site Investigation: Factors such as climatic conditions of the region where the foundation is located, groundwater level, and soil type should be evaluated.

  • Structure Type: Suitable insulation methods should be determined for different building materials such as reinforced concrete, stone, and brick.

2. Material Selection

  • Bituminous Materials: It is one of the most widely used materials for waterproofing. Although it is generally used in roof insulation, it is also effective in foundation insulation.

  • Liquid Membranes: Polyurethane or epoxy-based liquid membranes form a smooth and flexible insulation layer.

  • Cement Based Insulation: Insulation layers created with water resistant cement mixtures.

Foundation insulation with waterproofing to prevent moisture issues.

3. Ground Preparation

Dirt, oil, dust and old insulation materials must be thoroughly cleaned from the foundation surface. Chemical cleaners can be used if necessary. Cracks, holes or roughnesses on the concrete surface should be filled and leveled. This step is important to minimize water penetration. A smooth surface ensures better adhesion of the insulation material.

4. Application of the Insulation System

  • Bituminous Insulation: It can be applied hot or cold. While hot bitumen is applied as a roll by heating, cold bitumen is applied in solution or mastic form.

  • Liquid Membrane Application: It is applied by brush, roller or spray method. It forms a thin and flexible layer.

  • Cement Based Insulation: It is prepared by mixing water and binding materials and applied on the foundation surface. Additional additives are usually added to provide waterproofing.

  • Drainage Materials: Drainage pipes or drainage boards can be used for the effectiveness of waterproofing. This ensures that groundwater is collected and removed around the foundation.

  • Protective Coatings: Protective coatings can be applied to protect the insulation layer. This ensures that the insulation material is resistant to mechanical damage.

5. Detailing and Additional Measures

Special insulation techniques should be applied at corners and joints. These areas are critical points where water can leak. Beams should be completely in contact with the insulation material and should be waterproofed. Layers of insulation materials should be properly joined and no gaps or voids should remain. After the application, waterproofing tests should be carried out and the effectiveness of the insulation should be checked.

6. Drying and Hardening Process

Insulation materials should be allowed to dry and harden completely for the time specified by the manufacturer. This period may vary according to the material type. Temporary protective measures should be taken to prevent damage to the insulation layer after application. For example, it should be ensured that heavy loads are not placed on the foundation.

Foundation insulation with damp proofing applied to corner for moisture protection.

7. Final Controls

It is checked whether the insulation layer is homogenous and whether there are cracks or gaps. The effectiveness of the insulation can be tested by methods such as flood test.

The insulation materials applied, the methods used and the test results should be recorded in detail. This will be a reference for future maintenance and repairs.

Protecting buildings against water is a critical element that directly affects the life and safety of the building. Foundation waterproofing is one of the most important steps required to protect the foundation from external factors such as water and moisture. 

Thanks to methods such as membrane application on the foundation, foundation bundling, and foundation insulation, the foundation is covered with a waterproof layer. Complete and correct execution of these applications guarantees that the building will remain solid for many years.

If you want to protect your foundation against water, you should use quality foundation waterproofing materials and get support from a professional team. A foundation that is not waterproofed can cause major structural problems in the long run and increase costs exponentially.

Remember, the most important point to be considered when waterproofing the foundation is the use of the right materials and the meticulous coating of all surfaces. Without foundation waterproofing, the structure may leak water, the reinforcement may rust and the structure may weaken and decay over time. Remember, you can contact Haydar Boz for your questions regarding your building projects and achieve the best results!