What is Subasman in Prefabrication? Level, Curtain and Height

Prefabricated buildings are an increasingly common construction method today. These structures are preferred in many different areas thanks to their ability to be built quickly and economically. However, some technical issues need to be considered during the construction stages of prefabricated buildings. One of these issues is the concept of subbasement in prefabrication.

Subasman is a platform at ground level starting from the foundation level of the building. This platform is usually made of reinforced concrete and provides support to the structure. In this article, we have examined the details and importance of the concept of sub-base in prefabricated buildings.

What is Subasman?

Since prefabricated houses are constructed by assembling prefabricated building blocks, they have a built-in sewage system for water and wastewater management. This system is located in a pit under the house or in the subsoil area.

Subsoil can be defined as a reinforced concrete area below the foundation level of the house. Because this part is located at the bottom of the house, it is also called the basement. It is important to prevent water accumulation in the areas under the house and to protect the base and foundation of the house.

In prefabricated houses, the sub-base is usually made of modular panels under the house. Joining these panels together creates a frame under the house, on which the floor of the house is placed. The subsoil extends to the foundation level of the house and includes a sewage system for the drainage of water under the house.

How to Build Subasman in Prefabricated Buildings?

Sub-base construction in prefabricated buildings may vary depending on the design and location of the house. However, generally, sub-base construction in prefabricated houses is carried out with a process that includes the following steps:

1. Foundation Works: Subsoil construction begins with work on the foundation of the house. The foundation forms the carrier system under the house and ensures that the areas under the house are properly supported. Therefore, the foundation of the house is built first.
2. Installation of Panels: The sub-base panels used in prefabricated houses are steel or reinforced concrete panels that are usually placed under the house. These panels form the frame under the house. The joining of the panels creates a frame under the house and the floor of the house is placed on this frame.
3. Sewerage System: In the subsoil zone, there is a sewage system for the drainage of water under the house. This system may include elements such as drainage pipes, drainage pits, pumps and other equipment. The sewage system allows the water under the house to drain away and helps prevent water from accumulating under the house.
4. Insulation: In the subsoil zone, insulation materials are used to reduce the humidity under the house. Therefore, the subsoil floor and walls are covered with insulating materials. These materials prevent the evaporation of moisture accumulated under the house and protect the air quality inside the house.
5. Flooring Material: In the subsoil zone, the floor material to be laid under the house is determined. This material is usually a durable and water-resistant material. Depending on the humidity level under the house, a waterproof surface may also be preferred.

The construction of the sub-base in prefabricated houses is completed with the implementation of these steps. The correct construction of the subsoil is of great importance in terms of water management under the house and protection of the foundation of the house.

How Much Should the Subbasement Height Be?

The subsoil height may vary according to the design and location of the prefabricated building. However, generally, the subsoil height is determined in accordance with the minimum heights specified in local regulations. For example, according to the regulations specified in the Law No. 6306 on the Transformation of Areas Under Disaster Risk, Türkiye, the sub-base height of the buildings should be at least 30 cm.

The height can vary depending on the intended use of the space under the house. For example, it may be higher if the area under the house is to be used as storage space. In addition, the location of the house and environmental factors also play a role in determining the height of the sub-base. For example, if you live in a rainy area, the subsoil should be higher so that water that accumulates under the house can drain away.

What is Subsoil Filling?

Subgrade fill is one of the most widely used filling materials among building materials. It is usually made using gravel, sand, stone or crushed stone. The filling materials must be carefully selected to completely fill the space under the house. It should be placed in such a way that it forms a solid base with adequate compaction.

Since the subsoil filling is used to fill the space under the house, its contribution to the structure is great. The backfill increases the bearing capacity of the ground under the house and gives the structure more durability. It also helps to drain the water that accumulates under the house.

What is Subasman Curtain?

Subsoil curtain is a curtain wall constructed under the foundation curtain in order to reinforce the ground and increase the height of the foundation. It is used to increase the height of the walls in the area of the building in contact with the ground. In this way, damages that may be caused by the movements of the ground can be prevented and the structure can be given more durability.

Concrete is generally used in the construction of sub-base walls. The material can be used in different varieties according to the height, width and thickness of the sub-base curtain. Since concrete is a durable and robust material, it is often preferred in the construction of sub-basement curtains. During the construction of the sub-base curtain, it is made during the construction of the foundation curtain and poured at the same time. It is built as reinforced concrete together with the foundation curtain.

What is Subasman Level?

Subsoil elevation is the level of the ground below the foundation wall of a building, which is taken as a reference in construction projects. Elevation is a term used in the construction industry as a measure of height and refers to the distance of a surface from a certain reference level. Subsoil elevation refers to the height of the ground level below the foundation of a building.

The subsoil level is determined by taking into account the soil structure and height in the region where the construction project is planned. The space under the foundation wall of the building must be filled according to the subsoil level determined in the construction project. In this way, the foundation of the building can be placed more firmly on the ground and damages caused by ground movements are prevented. Incorrect determination of the elevation may cause the foundation of the building not to be firmly established and damage to the structure.

How to Determine the Subsoil Level?

Accurate determination of the subgrade elevation ensures that the foundation of the building is firmly established and makes the structure more resistant to damage caused by ground movements. The parameters examined when determining the subsoil elevation are as follows:

• Ground survey
• Building height
• Ground level
• Height of the foundation wall
• Thickness of the filling material

The subsoil level is calculated according to the above factors. The subsoil level is determined by taking into account the ground level, the height of the foundation wall, the thickness of the filling material and the total height of the structure.