Rollag Foundation: Definition, Function, Types, & Advantages

Rollag foundation is a simple type of foundation commonly used in building houses, especially in Indonesia. Although it seems simple, this foundation plays an important role in balancing and supporting buildings.

To ensure strong and durable construction, the type of foundation must be chosen according to the structure above it. Let's learn more about the definition, function, types, and advantages of rollag foundations in building construction.

What Is a Rollag Foundation?

A rollag foundation is a type of shallow foundation made of stacked bricks arranged with a mixture of concrete, sand, and cement. This foundation is commonly used to support the load of a building and transfer the load from the walls to hard soil.

The depth of the soil excavation for a rollag foundation is usually between 50–80 cm. Although it was widely used in the past, rollag foundations are now rarely used to support heavy loads because they are complicated to build, time-consuming, expensive, and not reliable enough for heavy loads.

However, rollag foundation is still used to support light loads, such as on terraces, and to balance the position of the floor to prevent it from sinking. Rollag foundation is not as strong as suspended beams, but they are also not as expensive as suspended beams.

Functions of Rollag Foundation

Rollag foundations are often chosen as a solution for simple buildings, especially when looking to save on construction costs. Typically, these foundation is combined with reinforced concrete foundations to remain strong yet efficient. Here are some general functions of rollag foundation:

Supporting lightweight buildings on unstable ground.
Distributing the building's load to the ground so that the load distribution remains balanced and does not cause cracks or damage.
Maintaining the stability of the floor position so that it does not sink, especially at the edges.
Serving as a base layer or floor support so that the entire floor surface stays level.
Used as a barrier, such as on terraces, fences, and home parking areas.

Types of Rollag Foundation

Rollag foundation is divided into two types based on its constituent materials. Each has different characteristics and uses according to construction needs. Here is the explanation.

1. Concrete Rollag

For two-story house construction, a solid concrete rollag foundation is more often chosen. This method involves pouring concrete mixed with crushed stone directly into a trench lined with a frame.

2. Brick Rollag

Brick rollag foundation uses red bricks as its primary material. Red bricks are chosen because they are considered to have high density or solidity, and are relatively affordable, making them a popular choice for residential construction.

Advantages and Disadvantages of Rollag Foundation

Before choosing a rollag foundation for building construction, it is important to understand its advantages and disadvantages. This can help you adjust its use to your needs and land conditions. Here are the advantages and disadvantages of the rollag foundation.

Advantages of Rollag Foundation

Rollag foundation has a few advantages that make it still used in certain conditions, such as:

Material efficiency: Due to its small construction area, this type of foundation requires only a small amount of material, consisting of stacked bricks adhered with concrete mortar.
Easy construction process: The small size of the foundation makes the construction process easier. It is generally shaped like an inverted trapezoid with a central section containing pegs and concrete mortar as an adhesive.
Neater finish: The simple shape of the foundation creates a neater finish and makes it easier to attach to other building structures.
Dual function as a barrier: In addition to serving as a foundation, rollag can also be used as a barrier between areas, such as on terraces, helping to conceal the building's dimensions.

Disadvantages of Rollag Foundation

Although quite practical, rollag foundations have several disadvantages that need to be considered before use, such as:

Limited strength: This foundation does not have a strong bearing capacity, so it is only suitable for simple buildings and is not recommended for multi-story houses.
Requires a large excavation area: The process of constructing this foundation requires extensive excavation along the length of the building walls.
Only suitable for stable soil: This foundation can only be used in areas with sufficiently stable soil conditions.
Not resistant to waterlogging: It is not recommended for use in flood-prone areas or areas that are often waterlogged because of its low water resistance.

Tips for Installing Rollag Foundations

Rollag foundations can be the right choice for simple constructions, such as guard posts or residential houses. However, due to the complexity of its construction, you need to pay attention to several things to ensure its strength and safety. Here are some important tips when installing rollag foundations:

Ensure that the soil structure is in good condition so that it does not experience adjustments or shifts.
Plan carefully to make the construction process more economical and efficient without dismantling and reassembling.
Adjust the type of foundation to the structure of the building to be constructed.
Foundation planning must consider the function of the building, soil type, hard soil depth, and budget.
Use rollag foundations as area boundaries, not as the main support for the building.
Ensure that the use of this foundation meets standards of feasibility and environmental protection.

Working Principle of Rollag Foundation

Rollag foundation is a type of pile foundation designed to support structural loads on soft or unstable soil conditions. These foundations consist of reinforced concrete piles driven into the ground and connected to concrete beams as the base of the structure. The working principle of rollag foundations can be explained through the following steps:

Concrete piles are driven into the ground using special pile driving equipment.
The piles are then connected with reinforced concrete beams cast above ground level.
The load from the building structure is transferred to the piles through these concrete beams.
The piles then transfer the load to deeper, more stable soil layers so that the building structure can stand firmly.

In addition, the strength or bearing capacity of rollag foundation is greatly influenced by several factors, including:

Soil type and characteristics: The characteristics of the soil at the construction site greatly determine the foundation's ability to support loads.
Pile depth and length: Piles that are driven deeper and longer usually have a higher bearing capacity.
Pile cross-sectional area: The cross-sectional size of the pile also plays a role in determining the strength of the foundation.
Concrete quality and strength: The quality of the concrete material used for the piles and beams greatly affects the bearing capacity of the foundation.
Pile installation method: The way the piles are driven also contributes to the overall effectiveness of the foundation.

That is a complete explanation of rollag foundations, from their definition, function, types, to their advantages. Choosing the right type of foundation is very important to ensure that the house remains balanced, sturdy, and durable.

To optimize construction, ensure you use high-quality building materials, including cement. Semen Merah Putih Watershield is a super-premium multi-purpose cement solution with water-repellent technology that protects against moisture from three sources: exterior, interior, and soil.

This cement is ideal for various building applications, including foundations, as it prevents corrosion of reinforcing bars and maintains structural strength with minimal maintenance. Contact us for more information about high-quality cement and concrete products from Semen Merah Putih and find the best solutions for your construction.