01 - General & Defects

Question 1

What are historic construction materials and techniques (in NZ)?

Answer 1

Early construction
- Māori construction - Māori used materials found in the forest and swamps, such as wood, bulrush, and stone. They wove materials together without nails.
- Earth houses - Settlers from Britain built cob houses in the 1840s and 1850s using layers of clay, straw, and grass.
- Wooden houses - Timber was the most common material for building houses because of the country’s abundant forests.

Later construction
- Light timber framing - A skeleton of small timbers was covered with weatherboards to create a weatherproof exterior.
- Stone buildings - Stone was used for churches, banks, and public buildings, but was expensive and damaged by earthquakes.
- Concrete, brick, and board - These materials became more common after the 1930s as timber construction became more expensive.
- Prefabricated houses - After World War II, companies produced prefabricated houses using radiata pine and other materials.

Question 2

What architectural styles are present in New Zealand?

Answer 2

View the Archiectural-Eras PDF:

Georgian Style: Pre-colonisation during the 1820s and 1830s.
Neo-Classical: This style was popular between 1900 and 1930.
Modernist: This style was introduced in the 1930s.
Californian Bungalow: This single-level wooden building with a verandah became popular in the early 20th century.

Question 3

What are the typical defects in Elizabethan buildings?

Question 4

What are the typical defects in Georgian buildings?

Answer 4

1. Leaning chimneys
2. Overloading of roof due to change of materials (e.g. concrete tiles)
3. Removal of chimney breasts but not the stack
4. Blocked internal gutters
5. Brick walls prone to distortion due to lack of restraint at each floor level
6. Damp penetration through solid walls
7. Rotting timber joists that are built into external wall
8. Dry rot caused by poor cross-ventilation in narrow, long terraces
9. Shallow foundations causing dropping of central spine wall
10. Damp basements

Question 5

What are the typical defects in Victorian buildings?

Answer 5

1. Leaning chimneys
2. Overloading of roof due to change of materials (e.g. concrete tiles)
3. Removal of chimney breasts but not the stack
4. Damp penetration through solid walls
5. Rotting timber joists that are built into external wall
6. Wall tie failure (if a cavity wall, particularly in black ash mortar)
7. Differential settlement of bay windows (little to no foundations)
8. Rising damp caused by lack, failure or bridging of DPC
9. Blocked air vents to ground floors, causing dry rot
10. Lead water pipes

Question 6

What defects would you expect to see in properties built between 1945-1970?

Name some common defects in a 1970s building.

In a steel frame brick wall 1950s building, what particular defects would you be looking for?

Question 7

What are the typical defects in 1960’s high-rise office buildings?

Answer 7

1. Flat roof problems
2. Parapet walls (loose copings)
3. Poor workmanship (inadequate re-bar cover)
4. Concrete defects - carbonation/chloride attack
5. Deleterious material - asbestos/HAC/brick slips
6. Cold bridges
7. Overloading of floors (filing cabinets)
8. Poor access and egress - narrow staircases, change in levels
9. Brittle metal windows
10. Corrosion of steel fixings

Question 8

What are the typical defects in New Zealand buildings?

Question 9

Cause and effect of defects

Question 10

Cause and mechanics and types of failure

Question 11

Types and limitations of testing

Question 12

Specialist Inspections

Question 13

Testing equipment

Question 14

Use of sketches, drawings and photographs

Question 15

Remedial or preventative works