Foundations (Strip, Raft, Pile)
Choosing and building the right base for the soil and the load.
Foundations transfer the load of a building safely to the ground. The three main types are strip (continuous concrete under load-bearing walls, suited to stable soils and lighter loads), raft (a single slab spreading load across the whole footprint, used on weak or variable soils) and pile (deep columns transferring load to firmer strata, used for poor surface soil or heavy structures). The right choice depends entirely on soil conditions, building load and groundwater.
Common Damage
1. Settlement & Subsidence
- Foundations sinking unevenly into the ground
- Caused by clay shrinkage, leaks or weak soil
- Stepped cracks appearing in brickwork above
2. Heave
- Upward movement from swelling clay soils
- Often follows tree removal or wet seasons
- Pushes foundations and ground floor slabs upwards
3. Foundation Cracking
- Cracks running through footings or pile caps
- Caused by overloading or differential movement
- Visible in walls, floors and external paths
4. Water & Erosion Damage
- Tree roots drawing moisture from clay
- Drainage leaks washing soil out from beneath
- Frost action on shallow foundations
Repairs
minor Repairs
- Crack monitoring with telltales
- Improve surface drainage and downpipes
- Localised repointing and sealing
moderate Repairs
- Grouting to fill voids beneath footings
- Helical bar reinforcement to spanning walls
- Targeted underpinning of one or two bays
major Repairs
- Full traditional mass-concrete underpinning
- Retrofit mini-piles to support failing footings
- Resin injection ground stabilisation beneath foundations
New Installation
When Replacement Is Needed
- New build, extension or replacement structure
- Soil report indicates weak or variable ground
- Heavy structures or tall buildings
- Sites with high groundwater or shrinkable clay
Installation Steps
Strip Foundations
- Excavate continuous trench under load-bearing walls
- Lay reinforcement where needed
- Pour concrete to design depth and width
Raft Foundations
- Excavate and level the full footprint
- Lay damp-proof membrane and insulation
- Place reinforcement mesh and pour slab in one go
Pile Foundations
- Drill or drive piles to firm strata or rock
- Cast pile caps to spread load to walls or columns
- Tie piles together with ground beams
Drainage & Waterproofing
- Install land drains around perimeter
- Apply tanking or DPM where required
- Direct surface water away from the building
Lifespan
- Strip Foundations
- Design life of building (100+ years)
- Raft Foundations
- 100+ years if drainage is maintained
- Pile Foundations
- 100+ years in stable conditions
- Underpinning
- Permanent when correctly designed
Warning Signs
- Diagonal or stepped cracks above DPC
- Doors and windows sticking or out of square
- Sloping floors or visible movement in walls
- Gaps opening between extension and main house
- Sinking paths, patios or driveways next to walls
Other Construction Services
Drainage Systems
Foul, surface and sustainable drainage that keeps the site dry.
Utility Connections (Water, Gas, Electric)
Safe, certified connections to mains water, gas and power.
Ground Levelling & Compaction
Even, stable ground that won't settle under your build.
Concrete Works
From foundations to slabs — concrete designed, placed and cured properly.
Steel Framework
Strong, fast structural steel — fabricated, erected and protected.
Timber Framing
Warm, flexible timber structures — kept dry, treated and well-ventilated.
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