Prices and estimates for swimming pool earthworks
Earthworks are all the operations involved in preparing the ground before building a swimming pool. This includes excavating, moving earth, levelling the ground and laying solid foundations.
The main objectives of earthworks are :
- Preparing the ground Make sure the ground is ready to receive the pool structure by removing any obstacles and creating a level surface.
- Ensuring stability Reinforcing the ground so that it can bear the weight of the pool and water, thus preventing subsidence and ground movement.
- Preventing structural problems To avoid cracks and other damage that could occur if the pool is built on poorly prepared ground.
The importance of earthworks in swimming pool construction
The earthwork has a direct influence on the longevity and safety of your pool. Properly laid groundwork will ensure that your pool remains stable and functional for many years to come.
Bad earthworks can have serious consequences.
- Cracks Poorly prepared ground can shift or settle, causing cracks in the pool structure.
- Ground movements Ground movement: if the ground is not properly stabilised, ground movement can occur, damaging the pool and surrounding facilities.
- Drainage problems Poor drainage can lead to water accumulating around the pool, causing seepage and damage to the structure.
Landscaping must be carried out with care and expertise to ensure the durability and safety of your pool. Ignoring or botching this step can lead to high repair costs and long-term safety risks.
Stages of earthwork for a swimming pool
Site survey
Before starting any earthworks, a geotechnical analysis of the site is essential. This study assesses the composition of the soil, its stability and its ability to support the weight of the pool. The geotechnical analysis includes tests to determine the nature of the soil (clay, sand, rock, etc.), its compaction and its load-bearing capacity.
The importance of this stage cannot be underestimated. It enables technical difficulties to be anticipated and earthmoving methods to be adapted accordingly.
For example, clay soil will require specific drainage techniques to avoid water accumulation, while rocky soil may require more robust excavation equipment.
A good site survey ensures adequate preparation, minimises the risk of soil movement and guarantees the long-term stability of the pool.
Delimitation and marking
Once the site survey has been completed, the next step is to mark out and mark the location of the pool. This phase ensures that the pool will be installed exactly where you want it, with the right dimensions and alignments.
Marking techniques include the use of stakes, ropes and site paint to outline the pool on the site.
Specific tools such as laser levels and theodolites are used to ensure maximum precision. It is essential to follow the construction plans to the letter to avoid any shifts or errors that could complicate the subsequent stages.
Precise delineation also ensures that excavation and earthworks are carried out efficiently and in accordance with project specifications.
Excavation
Excavation is the stage when the ground is dug up to create the space needed for the pool. There are two main methods of excavation: manual and mechanical.
Manual excavation This method involves the use of hand tools such as shovels and picks. It is generally used for small pools or in areas where access is limited for heavy equipment. Manual excavation is more precise for detailed work, but is laborious and time-consuming.
Mechanical excavation This method uses heavy machinery such as excavators, bulldozers and backhoes. It is much faster and more efficient, especially for large pools. The machines can dig to precise depths and dimensions in a very short space of time.
Excavation depth and dimensions depending on the type of pool
The depth and size of the excavation will depend on the type of pool you wish to install. For example, a standard swimming pool requires a depth of at least 1.5 to 2 metres, while a children's pool or mini pool can be much shallower.
Concrete pools They can be of various shapes and depths, often requiring more complex and deeper excavations.
Vinyl and fibreglass pools These pools have predetermined dimensions, which simplifies excavation by simply following the manufacturer's specifications.
Evacuation of spoil
Once the excavation is complete, all that remains is to manage the spoil. Excavated earth must be properly treated to minimise its environmental impact.
Storage Excavated material can be temporarily stored on the construction site. Choose a location that does not interfere with work in progress and that complies with local regulations on the storage of excavated materials.
Recycling Excavated material: some of the excavated material can be reused on site for gardening or levelling projects. Materials such as gravel and stone can be recycled and used for other constructions.
Evacuation Excess soil must be transported to appropriate landfill sites.
Preparing the base
Proper preparation of the base ensures stability and increases the pool's lifespan. This includes levelling and compacting the ground and laying layers of specific materials to create a solid base.
Levelling and compacting the ground
Once the excavation is complete, the ground must be carefully levelled to create a flat, even surface. The aim is to avoid any settling or shifting of the pool after installation.
This stage involves compacting the soil to increase its density and stability. Specific equipment, such as vibrating plate compactors, are used for this task. Compaction reduces voids in the soil, minimising the risk of future movement and ensuring a solid base for the pool.
Layers of gravel or sand
After levelling and compacting, one or more layers of materials, such as gravel or sand, are installed. These layers provide a stable base and facilitate water drainage.
Gravel Gravel: gravel is often used as the first layer because of its ability to drain water and withstand heavy loads. A 10 to 15 cm layer of gravel is generally sufficient to ensure good stability.
Sand A layer of sand is then placed on top of the gravel to create a smooth, even surface on which the pool can be installed. The sand also corrects any small irregularities in the bottom.
These materials must be carefully levelled and compacted to ensure a perfectly flat and stable base.
Drainage and water management
To prevent water from accumulating around and under the pool, effective drainage systems need to be installed. These systems generally include perimeter drains and pipes that direct the water away from the pool.
Installation of drainage systems
Peripheral drains Installed around the pool, these drains collect rainwater and water infiltration, directing it into specific pipes.
Pipes These pipes carry the collected water to a drainage point, such as a drainage trench or a rainwater retention system.
Importance of rainwater and groundwater management
The aim of effective rainwater and groundwater management is to maintain the structure and durability of the pool. Rainwater can cause flooding and ground movement, while groundwater can exert upward pressure on the pool, leading to cracks or displacement.
Rainwater management Rainwater management: includes the collection and evacuation of rainwater to prevent it accumulating around the pool. Gutters, drains and retention basins are key elements of this system.
Groundwater management uses underground drains to direct water away from the pool, reducing hydrostatic pressure on the structure
Factors influencing the price of earthworks
The impact of soil type on earthworks prices
Soil composition can significantly affect preparation methods, the equipment required and working time, all of which have a direct impact on overall prices.
Impact of soil composition on techniques and prices
Clay soils Clay soils: clay soils offer good stability once compacted, but can pose problems in terms of drainage and working. Excavating in clay soil may require special techniques to prevent water accumulation and landslides. These additional measures can increase the cost of earthworks.
Sandy soils Sandy soils: sandy soils are easy to excavate and offer excellent drainage, but they often require additional reinforcement to prevent subsidence. Adding stabilisers and compaction materials increases costs.
Rocky ground Excavation in rocky ground is particularly costly and requires heavy, specialised equipment, such as jackhammers or controlled explosives. The time and effort required to break up and remove the rock can drive up costs.
Examples of easy vs. difficult groundworks
Soils that are easy to level Loamy soils: loamy soils and loose soils are generally simpler and less expensive to excavate. They allow rapid excavation and require less reinforcement.
Soils that are difficult to dig Soils composed of stones, heavy clay or solid rock. These soils require advanced techniques and specialised equipment, which increases labour and material costs.
Pool size and shape
The size and shape of the pool directly influence the cost and complexity of the earthworks.
Pool size The larger the pool, the larger the excavation will be, requiring more time and resources. A large pool requires more labour and materials for earthworks, which increases costs. For example, a 10×5 metre pool will require more extensive excavation and additional stabilisation measures than an 8×4 metre pool.
Pool shape Rectangular or square swimming pools are generally simpler and less expensive to dig, as they require standard digging techniques and less cutting and shaping of the ground. On the other hand, free-form pools with complex curves and angles require more detailed and precise earthworks, which can increase time and labour costs.
Earthworks prices: summary table
To give you a better understanding of the costs associated with earthworks as a function of the various factors, here is a summary table showing estimated costs for each phase and element.
| Stage | Description | Price estimates |
| Site survey | Geotechnical and topographical analysis | 500€- 1 500€ |
| Delimitation and marking | Marking techniques and use of tools | 200€ – 500€ |
| Manual excavation | Labour for small pools | 30€ - 50€ / hour |
| Mechanical excavation | Use of excavators and bulldozers | 70€ - 150€ / hour |
| Evacuation of spoil | Storage, recycling and disposal of materials | 200€ – 800€ |
| Preparing the base (gravel) | Laying layers of gravel | 30€ - 50€ / m³ |
| Preparing the base (sand) | Layers of sand | 20€ - 40€ / m³ |
| Drainage systems | Installation of perimeter drains and pipes | 500€ – 2 000€ |
| Rainwater management | Setting up collection and disposal systems | 1 000€ – 5 000€ |
| Geotextile materials | Laying geotextiles to stabilise the soil | 2€ - 5€ / m² |
| Planning permission | Obtaining the necessary authorisations | 100€ – 500€ |
| Safety and signage | Installation of barriers and road signs | 100€ – 300€ |
| Training and PPE | Protective equipment for workers | 50 - €150 per person |
| Maintenance of drainage systems | Regular inspections and maintenance | 50 - €150 per person |
To ensure the success of your project, it is highly recommended that you consult earthmoving professionals. They can provide personalised quotes, expert advice and ensure that all stages are carried out in accordance with local standards and industry best practice. Don't hesitate to contact the experts to help you throughout your pool construction project.
