Construction Tech

Question 1

What is the formation of a basement retaining wall?

Answer 1

A series of adjacent piles to form an earth retaining and watertight structure, for example secant pile wall. Interlocking female and male piles formed using CFA method. Female piles first. Area inside the walls is then excavated.

Question 2

Difference between unitised and stick cladding

Answer 2

Unitised is a prefabricated system.
Prefab - quicker, increased quality, less labour.

Stick is on site, transoms and mullions form a grid and a panel is placed inside.
On site - specialist works, won’t get damaged arriving to site and design flexibility

Question 3

What is Approved Document L?

Answer 3

Conservation of fuel and power.

Question 4

What is Approved Document B?

Answer 4

Fire Safety.

Question 5

What is Approved Document F?

Answer 5

Ventilation.

Question 6

What is Approved Document P?

Answer 6

Electrical Safety.

Question 7

Detail the retaining wall system on Erith.

Answer 7

Kingpost retaining wall of various heights.

Drilling of holes where the posts will be installed
Install king posts
Install infill concrete panels

The cost of kingpost retaining walls vary dependant on their size. The average cost used per m2 on Cox Lane is £480m2

Question 8

How much are you paying for rebar?

Answer 8

The latest tender return I have is for Printworks and the average return price was at £1,300 per tonne.

Question 9

How much is concrete?

Answer 9

The latest tender return I have is for Printworks and the average return price was at £220 m3

Question 10

How much is formation?

Answer 10

£70 m2

Question 11

What is the rate of disposal of excavated materials?

Answer 11

Depends. Contaminated £200-400/m3, non-contaminated £70/m3

Question 12

What is the rate of steel?

Answer 12

The latest tender return I have is for Printworks and the average return price was at £5,500 per tonne

Question 13

What are the different types of piles?

Answer 13

Driven - arrives precast and driven into the ground. Causes noise and vibration, displaces soil

Bored - hole is drilled using a drilling rig. Concrete is poured insitu and reinforcement cage is dropped in. CFA is when an auger is used to excavate material and then as it is brought up concrete is poured, then reinforcement is dropped

Question 14

Why is piling considering for certain buildings?

Answer 14

Loading requirements, ground conditions and weight distribution

Question 15

What are the four grades of waterproofing?

Answer 15

Grade 1: Protection from basic dampness (non-living areas).
Grade 2: Dry for storage areas (occasional damp tolerance).
Grade 3: Habitable areas (fully dry).
Grade 4: High-sensitivity areas (no water or humidity).

Question 16

What are the main types of waterproofing?

Answer 16

Type A Barrier Protection
Type B Structural Integral Protection
Type C Drained Protection

Question 17

What type of waterproofing is required at grade 1?

Answer 17

Grade 1: Protection from basic dampness (non-living areas).

• Cementitious waterproofing, coating or slurries

Question 18

Talk me through the construction technology on one of your projects

Question 19

How do you construct a crane?

Answer 19

• Survey ground
• Construct a concrete base (depending on crane specifications and soil conditions).
• Assembly (a mobile crane used to lift the crane’s core components into place).

Question 20

How do you construct a retaining wall such as what’s on printworks?

Question 21

If a client had to reduce carbon, what would you look at in the design?

Answer 21

Embodied or Operational?

Embodied,
- structure, timber over concrete or steel for example
- reuse materials or recycled materials
- reduce transportation emissions
- refurbishment where possible

Operational
- renewable energy e.g. solar panels
- efficient lighting systems
- air tight design to reduce energy requirements
- optimise insulation