Groundworks are the most important part of any construction project. Although they’re not visible once everything is completed, the groundworks do a lot of the heavy lifting beneath the surface to keep everything securely in place for years to come.
Faulty groundwork can lead to various problems in buildings, including cracking, movement, damp issues, and structural instability, so it’s vital to get the installation right.
At the centre of all groundworks are footings and foundations. Let’s look at both, how they differ, and how to lay them to ensure strong, stable buildings.
Groundwork is one of the earliest and most important stages of any construction project. It covers all the preparation carried out before the main structure can be worked on above ground level.
Groundwork ensures structural stability, manages water movement and prevents future defects. It distributes loads safely into the ground and protects the building from settlement and subsidence. There are a few stages involved. Let’s take a look at them.
Before any excavation begins, the ground needs to be investigated. This can include soil surveys, contamination checks, locating existing services, and understanding the load requirements of the proposed structure.
The site must be cleared of vegetation, debris, old structures, and any unsuitable material. The right tools and machinery should be used to ensure the area is cleared efficiently and safely.
Excavation involves digging down to the required formation level. For strip or trench fill foundations, this means digging trenches to the specified depth and width.
Drainage is installed at this stage to manage surface water and foul water effectively. This may include underground drainage pipes, soakaways, and inspection chambers.
Where floors, driveways or hard standings are planned, a sub-base is then laid and compacted with a vibrating wacker plate compactor to guarantee a smooth surface.
With the ground prepared, the final step is to pour concrete into prepared trenches or to install reinforced systems.
Foundations are the structural elements that transfer the load of the building safely into the ground.
The role of foundations is to spread the weight of the building over a large enough area so the ground can support it without excessive settlement.
These are some common types of foundations used in UK construction:
Foundations are usually laid after excavation and inspection. In domestic projects, foundations are typically at least one metre deep, but this can increase significantly in shrinkable clay or near mature trees.
A footing is the widened part at the bottom of a foundation that spreads the load over a larger area of soil.
In traditional strip foundations, the poured concrete at the bottom of the trench acts as the footing. The wall or foundation structure is then built up from this base.
There are three types of footings:
Installation involves excavating to the required depth, ensuring the base of the trench is level and free of loose material, and pouring concrete to the specified thickness.
Choosing the right system for your project depends on several factors.
All foundations must comply with UK building regulations and any structural engineer’s design. Load calculations, building size, and the construction’s intended use all influence the type and size of foundation required.
Soil conditions are one of the biggest determining factors to choosing footings and foundations:
The bearing capacity of the soil determines how wide and deep footings need to be. In weaker ground, wider or reinforced foundations may be necessary.
A high water table can complicate excavation and curing. Effective drainage, including land drains and soakaways, must be factored into the design.
On sloping sites, stepped foundations are often used to maintain correct depth while following the ground profile.
While foundation design will vary depending on the structure and ground conditions, the core process usually remains the same:
Ensure stable footings and foundations in your building work by avoiding these common errors:
For reliable access to quality building materials and tools to support every stage of laying footings and foundations, Jewson provides a trusted supply network backed by trade expertise. Browse our range today or visit a branch near to you.