TECHNICAL ARTICLES
Concrete and similar materials cannot provide complete protection against groundwater on their own. Concrete surfaces and retaining walls in contact with the ground may allow water penetration over time, leading to dampness, reinforcement corrosion, and serious structural risks. Moisture and dampness not only have a negative impact on occupant health but can also cause corrosion of reinforcing steel, loss of material strength, and significant repair costs. Neglected waterproofing problems are known to be among the underlying causes of many forms of structural deterioration and, in severe cases, structural failure.
The first step in foundation waterproofing applications is typically the installation of the waterproofing system over the blinding concrete layer. One of the most common and proven solutions is the use of bituminous waterproofing membranes. In professional applications, it is critically important to install these membranes in two layers and to select products with cold-temperature resistance suitable for the climatic conditions of the project location. Membranes designed to withstand temperatures such as -5°C, -10°C, or -20°C should be selected according to the environmental conditions of the region. Following membrane installation, a geotextile protection layer should be applied, followed by protective concrete, before proceeding with the foundation construction.
As an alternative, pre-applied bonded waterproofing systems, often referred to as “proof systems,” have become increasingly popular in recent years. These materials bond directly to the foundation concrete through a specially designed surface layer. This creates a continuous bond to the concrete and helps prevent water from migrating between the waterproofing layer and the structure. One of the key points in proof-system applications is that reinforcement is installed and concrete is poured directly over the membrane without the need for a separate protective concrete layer.
Regardless of the quality of the waterproofing material used, its service life may be reduced if water is not effectively directed away from the structure. For this reason, a properly designed drainage system is one of the most important complementary elements of foundation waterproofing, particularly in soils with low permeability. The more hydrostatic pressure acting on the structure can be reduced, the longer the waterproofing system can be expected to perform effectively.
Drainage boards also play an important supporting role in this context. However, they should not be considered a waterproofing solution on their own. Their primary function is to protect the waterproofing layer and help direct water toward the drainage system.
Another method frequently preferred by professionals is the tanking system, commonly known in Türkiye as the “bohçalama” method. In this approach, the waterproofing system completely surrounds the foundation and retaining walls like a continuous envelope. By treating foundation and wall waterproofing as an integrated system, it helps prevent water from penetrating into the structure.
Ultimately, foundation waterproofing is a critical discipline that directly affects a building’s durability, safety, and economic service life. For professionals, the key issue is not simply selecting a waterproofing material, but adopting a comprehensive approach that includes choosing products suitable for local climate conditions, developing the correct construction details, and planning an effective drainage system.
A foundation waterproofing system that is properly designed and professionally installed can help protect a building and maintain its performance safely for decades.
Critical Considerations in Foundation Waterproofing
the foundation, structural system, roof, insulation, and building services. However, if even one of these components is inadequate, the entire building can be negatively affected, regardless of how well the other elements have been designed and constructed. Waterproofing is one of the most critical of these components. In particular, proper waterproofing measures at foundation level not only improve comfort but also directly affect the safety and durability of the structural system.Concrete and similar materials cannot provide complete protection against groundwater on their own. Concrete surfaces and retaining walls in contact with the ground may allow water penetration over time, leading to dampness, reinforcement corrosion, and serious structural risks. Moisture and dampness not only have a negative impact on occupant health but can also cause corrosion of reinforcing steel, loss of material strength, and significant repair costs. Neglected waterproofing problems are known to be among the underlying causes of many forms of structural deterioration and, in severe cases, structural failure.
The first step in foundation waterproofing applications is typically the installation of the waterproofing system over the blinding concrete layer. One of the most common and proven solutions is the use of bituminous waterproofing membranes. In professional applications, it is critically important to install these membranes in two layers and to select products with cold-temperature resistance suitable for the climatic conditions of the project location. Membranes designed to withstand temperatures such as -5°C, -10°C, or -20°C should be selected according to the environmental conditions of the region. Following membrane installation, a geotextile protection layer should be applied, followed by protective concrete, before proceeding with the foundation construction.
As an alternative, pre-applied bonded waterproofing systems, often referred to as “proof systems,” have become increasingly popular in recent years. These materials bond directly to the foundation concrete through a specially designed surface layer. This creates a continuous bond to the concrete and helps prevent water from migrating between the waterproofing layer and the structure. One of the key points in proof-system applications is that reinforcement is installed and concrete is poured directly over the membrane without the need for a separate protective concrete layer.
Regardless of the quality of the waterproofing material used, its service life may be reduced if water is not effectively directed away from the structure. For this reason, a properly designed drainage system is one of the most important complementary elements of foundation waterproofing, particularly in soils with low permeability. The more hydrostatic pressure acting on the structure can be reduced, the longer the waterproofing system can be expected to perform effectively.
Drainage boards also play an important supporting role in this context. However, they should not be considered a waterproofing solution on their own. Their primary function is to protect the waterproofing layer and help direct water toward the drainage system.
Another method frequently preferred by professionals is the tanking system, commonly known in Türkiye as the “bohçalama” method. In this approach, the waterproofing system completely surrounds the foundation and retaining walls like a continuous envelope. By treating foundation and wall waterproofing as an integrated system, it helps prevent water from penetrating into the structure.
Ultimately, foundation waterproofing is a critical discipline that directly affects a building’s durability, safety, and economic service life. For professionals, the key issue is not simply selecting a waterproofing material, but adopting a comprehensive approach that includes choosing products suitable for local climate conditions, developing the correct construction details, and planning an effective drainage system.
A foundation waterproofing system that is properly designed and professionally installed can help protect a building and maintain its performance safely for decades.