Most commonly used foundation for domestic construction in the last 60 years.

• Soil type • i.e. minimum depth in cohesive = 750mm (not usually less than 1m in clay) • minimum depth in non‐cohesive = 450mm

SIZE

2 storey building could have a foundation wider then 500mm special if soils isnt good

• Other factors – • Presence of trees • Risk of frost • Proximity to adjacent services

The majority of soils in the UK have sufficient bearing capacity to have a simple strip of concrete.

2 storey building could have a foundation 500mm wide

Building load

Bearing Capacity of the soi

The WEAKER the soil and HEAVIER the building the WIDER the strip

Working space for labourer

Cost

timing

HEAVEY

Cheap

The most common form of foundation

Additional cost (more concrete) • Economical? • Service entry ducts • Good access for lorry

No need for planking and strutting (cost savings) • Potential time and labour savings

• No additional working space required.

foundations can be used for sloping sites, where access is restricted (i.e. for piling), there are obstructions in the ground.

• number of obstructions (e.g. old basements) in ground

Designed by an engineer

where access for piling is difficult

Easy to do

for sloping sites

for larger foundations

– Always includes reinforcement

Cast in situ or precast.

cheap and easy to load

Spreads loads from ‘superstructure’ to piles

Cheap

strip or pier foundations cover 50% of footprint

stiffened and reinforced concrete which extend under the entire footprint of the building

No standard solution – individually engineered (expensive) (unlike strip)

significant differential settlement likely

Need a lot of time

t foundations have to be individually engineered, and cover the entire footprint of the building to ‘float’ the load across the soil.

former mining; or • where the soil has significantly poor load bearing capacity • e.g. peat, filled ground, soft clay, soft silty clay and soft sandy clay

mining subsidence is possible

soils is of very poor bearing capacity