Foundation Defects

Question 1

What sort of foundation issues are there?

Answer 1

Settlement
- A downward movement due to increased load
- Affects new building or buildings with additional load will settle to the bearing capacity of the soil

Subsidence
- When the ground beneath a property’s foundation sinks downwards, leaving the foundation unsupported

Heaving
- When the ground beneath the foundation swells resulting in an upward movement
- Can be due to the removal of trees
- Flooding

Improper site preparation
- Not compacting soil

Chemical attack
- Can weaken concrete mix
- Can cause it to expand
- Carbonation

Question 2

What is differential movement?

Answer 2

If two sections of a building are constructed off different
foundations or the ground is made up of different soil types or strata then one may settle more than another causing cracking between the two sections of the building.

This issue is
most common with extensions.