Types of Foundations for Building a Private House

Slab Foundation

The slab foundation is a monolithic reinforced concrete structure laid under the entire area of the building. This type of foundation provides uniform load distribution and is a reliable choice for construction on weak or heaving soils. In Italy, the design and construction of slab foundations is regulated by Norme Tecniche per le Costruzioni (NTC), which establishes requirements for load calculations, reinforcement and the quality of materials used.

Monolithic slab. This is a solid reinforced concrete slab laid under the entire area of the building. It is highly resistant to soil deformations, which makes it suitable for heavy buildings such as stone or concrete houses, especially on soils with low bearing capacity.

Main stages of monolithic slab construction:

• Preparation of the plot and leveling of the base.
• Laying waterproofing to protect the foundation from moisture.
• Reinforcement of the structure using steel reinforcement, which ensures its strength and durability.
• Concrete pouring in compliance with the standards established by NTC.

Insulated Swedish slab (ISS).
This modern type of slab foundation includes a layer of insulation under the slab, a warm floor system and sometimes utility lines. ISS is used in energy-efficient houses, as it minimizes heat loss and improves overall living comfort.

Advantages of ISS:

• Reduced heating costs due to the insulation that prevents soil freezing.
• Convenient installation of underfloor heating system.
• Fast construction and minimal impact on the environment.

When designing ISS, it is important to take into account energy efficiency standards provided in Italy, such as Decreto Requisiti Minimi, which establishes requirements for thermal insulation and heating systems.

The choice of a slab foundation must be based on the results of geological surveys and design calculations. In addition, all works must be carried out in accordance with Italian standards and under the supervision of a qualified technical specialist.

Pile Foundation

The pile foundation is a reliable type of base used to transfer the building load to stronger soil layers at a significant depth. Such a foundation is especially relevant on plots with weak or water-saturated soils, where traditional foundations may be insufficiently effective. In Italy, the construction of pile foundations is regulated by Norme Tecniche per le Costruzioni (NTC) and European standards such as Eurocodice 7 (Geotecnica).

Driven piles.

• Structure: Driven piles are made of reinforced concrete, steel or wood. They are driven into the soil using special impact or vibratory machines until they reach a dense layer.
• Application: Used for heavy buildings such as multi-storey houses, industrial facilities and bridges on weak and water-saturated soils.
• Advantages: High bearing capacity; fast installation, especially with specialized equipment; durability due to strong materials.

Technical aspects. Pile depth is determined by the project, taking into account soil characteristics and building weight. Settlement control of piles is mandatory to prevent building deformations. Pile installation work must comply with environmental safety rules provided in Italian regulations.

Bored piles.

• Structure: To create a bored pile, a borehole is drilled, then reinforced and filled with concrete. This process allows piles of individual size and length to be created.
• Application: Used for heavy buildings on weak soils, especially in dense urban areas where driven piles cannot be used due to vibration or noise.
• Advantages: Possibility of installation at any depth; no dynamic load on the surrounding soil; high design flexibility.

Italian standards and recommendations.
When designing a pile foundation, the requirements of Eurocodice 7, regulating pile calculations and tests, must be taken into account. It is also important to comply with NTC standards, which set requirements for materials, depth and allowable loads. For large projects it is recommended to involve a licensed geotechnical engineer who will carry out the necessary surveys and ensure that the project complies with local regulations.

Foundation Made of Foundation Blocks (FBS)

The foundation made of foundation blocks (FBS) is a structure consisting of precast reinforced concrete blocks laid on a prepared base. This type of foundation is used for buildings of various weight on stable and firm soils.

Composition and laying.
Foundation blocks (FBS) are reinforced concrete products of standard sizes manufactured at plants and transported to the construction site. The blocks are laid on top of each other using mortar to create a strong base that evenly distributes the building load to the soil.

Advantages:

• Fast installation: A foundation made of FBS allows earth and installation works to be completed quickly, since the blocks do not require additional concrete pouring on site.
• Maintainability: If necessary, blocks can be dismantled and replaced without significant time and resource costs.
• Durability: Due to the use of reinforced concrete, the foundation made of FBS has high strength and durability.
• Cost-effectiveness: This type of foundation is often more cost-effective compared to other options.

Application.
The FBS foundation is used for the construction of both light and medium-weight buildings, including private houses, industrial and warehouse buildings, as well as for facilities located on stable soils. It is ideal for plots with dense non-heaving soils that provide a good base for block installation.

Technical requirements and standards in Italy.
In Italy, the design and installation of a foundation made of FBS must comply with Eurocodice 2 (EN 1992) standards for the design of reinforced concrete structures and Norme Tecniche per le Costruzioni (NTC), which regulate the design, construction and strength verification of foundations. All construction stages, including block laying and reinforcement, must be carried out in accordance with safety and quality requirements.

Warm Foundation

The warm foundation is a structure in which a layer of insulation is placed under the slab or strip foundation to increase the building’s thermal insulation. This type of foundation is mainly used for energy-efficient houses, where minimizing heat loss and creating a comfortable indoor microclimate is an important criterion.

Composition and structure. The warm foundation includes the following elements:

• Insulation: This is the main element of a warm foundation, which can be made of various materials such as polystyrene foam, extruded polystyrene, polyurethane foam or mineral wool boards. These materials have good thermal insulation properties and can significantly reduce heat loss.
• Main foundation: It can be strip or slab, depending on the building design and soil type. It is important that the insulation is correctly installed and does not impair the strength characteristics of the foundation.
• Underfloor heating system (optional): In some cases, in addition to insulation, an underfloor heating system is laid on the foundation, which allows you to create additional comfort and energy efficiency in the house.

Advantages.

• Energy efficiency: The warm foundation helps reduce heat loss, which leads to lower heating costs and increased overall energy efficiency of the building.
• Comfort: Due to good thermal insulation, a stable temperature is maintained in the house, creating comfortable living conditions at any time of the year.
• Protection from freezing: Insulation under the foundation prevents soil freezing in winter, which is especially important for buildings located in cold regions.
• Environmental friendliness: The use of insulation materials such as polystyrene foam or other modern thermal insulation materials helps reduce the carbon footprint and makes construction more environmentally friendly.

Application.
The warm foundation is used for the construction of energy-efficient houses, cottages and other buildings where it is important to minimize heat loss. It is ideal for modern houses with high thermal insulation and heating systems that include underfloor heating. Such a foundation is especially popular in regions with cold climates, where significant savings on heating become an important factor.

Technical requirements and standards in Italy.
In Italy, the design of warm foundations is regulated by standards such as Norme Tecniche per le Costruzioni (NTC), as well as specific energy-efficiency requirements set out in Legge 10/1991 and Direttiva 2010/31/UE. These standards prescribe the use of certified thermal insulation materials and determine parameters for their installation depending on the type of foundation and climatic conditions of the region.

Organization of drainage prevents flooding, improves working conditions and reduces the risk of damage to materials and equipment.

Foundation on a Sand or Gravel Cushion

The foundation on a sand or gravel cushion is a structure where a layer of sand or gravel is created under the main foundation to improve drainage and prevent soil heaving. This type of foundation is ideal for light buildings located on wet or heaving soils.

Composition and structure.

• Sand cushion: Sand is used for uniform load distribution and drainage. It has good drainage properties, which allows preventing moisture accumulation under the foundation and protects it from heaving during freezing.
• Gravel cushion: Gravel, unlike sand, has larger grains and improves drainage even more. A gravel layer contributes to stability and resistance of the foundation, especially in areas with high humidity.

Advantages.

• Improved drainage: The sand and gravel cushion provides effective water removal, which is especially important on wet soils or in regions with high precipitation.
• Protection from heaving: The cushion prevents soil heaving that may occur when water freezes in the soil, which is particularly relevant for cold regions.
• Stability on weak soils: For light buildings, especially on wet or unstable soils, such a cushion increases the bearing capacity of the base, improving foundation stability.

Application.
This type of foundation is used for light structures such as small houses, summer houses, utility buildings or other facilities on wet, swampy or heaving soils. A sand or gravel cushion significantly improves the operational characteristics of the foundation, allowing it to withstand moderate loads and providing durability.

Technical requirements and standards in Italy.
In Italy, the design and construction of a foundation on a sand or gravel cushion is regulated by Norme Tecniche per le Costruzioni (NTC). According to these standards, the cushion must be carefully prepared and compacted to ensure strength and durability. The soil on which the cushion is laid must be examined for resistance to compression and heaving.

Each of these types of foundations has its own unique advantages and limitations, and the choice of a particular type depends on many factors. These include the geological conditions of the plot, such as soil type and stability, its moisture content and heaving potential, as well as the mass and design features of the building. In addition, it is important to take into account climatic conditions, precipitation level, soil freezing temperature and groundwater level.