Construction Technology Flashcards

1
Q

What are the typical components of site investigations?

A

 Objective is to systematically collect and record data to help in design / construction
 Should include anything on adjacent sites that may impact and:
 Boundary hedges / fencing
 Existing trees
 Size, depth and location of services – gas, telephone, electricity, water, drains
 Existing buildings
 Ground water conditions
 Soil investigations – trial pits etc

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2
Q

What are the main site considerations?

A
  • Access considerations – approach roads etc
  • Storage considerations
  • Accommodation
  • Temporary services
  • Plant
  • Fencing / hoarding
  • Safety and health
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3
Q

What are the main types of excavation?

A

Open – use battered excavation sides cut back to a safe angle, eliminates the need for temporary support work, can easily construct basement walls and fall BUT extra excavation costs and need a lot of free site space.
Perimeter Trench Excavation – trench dug wide enough to form basement walls, this is supported as required – basement walls are constructed and then the inside of the basement is excavated.
Complete Excavation – used in firm subsoil’s. The Centre of the basement is excavated first, then the basement slab cast while the sides of the excavation are supported by struts.

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4
Q

Under what conditions would expect a raft foundation to be used for a substructure?

A

 Lightly loaded buildings on poor soils
 Where underground services i:e train lines dictate the use
 Where it may be impractical to create individual strip or pad foundations for a large number of individual loads. In very general terms, if strip or pad foundations would cover 50% or more of the floor area, then a raft may be appropriate.

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5
Q

What are the different types of piling and when would you expect them to be used?

A

 Sheet piles – a deep trench is excavated and concrete is poured in situ. The piles can be used to form basement walls or act as retaining walls.
 Secant piles – interlocking piles (male and female, often different diameters and hardness) are bored to provide a combination of foundations and basement walls. They go some way in providing a waterproof structure. Secant piles are often seen when a top down construction method is used.
 Bored Piles – an auger is used to excavate the soil and then concrete is poured in once complete. A variation to this is CFA (Continuous Flight Augured) where the piles are bored, Bentonite slurry is pumped in to stop the core collapsing and then concrete (which is denser than Bentonite) is poured in. Bentonite is environmentally harmful and is therefore not often used in the 21st century.
o Pre-cast piles – pre-cast piles are brought to site and hammered into the ground. Not often favoured due to the high noise levels associated with installation and the lack of flexibility in terms of depth required.

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6
Q

What is the difference between bored/pre-cast piles? What are the problems to the PQS regarding cost control with piling? Whose risk is the piling?

A

o Bored piles are defined when the process for removing the spoil to form the hole for the pile is carried out by a boring technique. They are used primarily in cohesive subsoil’s for the formation of friction piles and when forming pile foundations close to existing buildings where the allowable amount of noise and/or vibration is limited.
o Pre-cast Concrete piles are generally used where soft soil deposits overlie firmer strata. These piles are usually driven using a drop or single action hammer.

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7
Q

Explain how CFA piles work?

A

o Piling mat
o Rig is moved into position.
o Drill spins/drills to desired into the desired depth
o The concreting process is then commenced, whereby the auger is pulled out whilst the concrete is poured in.
o The reinforcement cage is then installed after the concrete has been poured – this is assisted by a hydraulic hammer to get it to the desired depth.

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8
Q

What is contiguous piling?

A

A line of non-interlinked piles in a sequence

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9
Q

What are grade 1 basements?

A

1- Some leakages and damp areas tolerable. Local drainage may be required. Used in Car parking
Plant rooms (excluding electrical equipment)
Workshops

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10
Q

What are grade 2 basements?

A

No water penetration but damp areas tolerable dependant on the intended use. Ventilation may be required to control condensation.
Used in Workshops and Plant rooms requiring drier environment than Grade 1 storage

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11
Q

What are grade 3 basements?

A

Dry environment. No water penetration. Additional ventilation, dehumidification or air conditioning appropriate to intended use. Ventilated residential and commercial areas including offices, restaurants, and leisure centres etc.

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12
Q

What are grade 4 basements?

A

Totally dry environment. Requires ventilation, dehumidification, or air conditioning appropriate to intended use. Used in Archives, Landmark buildings, and stores requiring a controlled environment

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13
Q

Can you tell me about what forms of modern methods of construction you are aware of.

A

Cross laminated timber
Modular construction
3D Printing

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14
Q

What is TM59 (CIBSE Guidance) 2017?

A

The most recent CIBSE TM59:2017 standardises the assessment method for dynamic thermal modelling of overheating at homes.
In order to comply with the CIBSE TM59 Overheating Methodology the following two criteria need to be passed for naturally ventilated rooms.

For Living Rooms, Kitchens and Bedrooms – The number of hours during which ΔT is greater than or equal to one degree (K) during the period May to September inclusive shall not be more than 3% of occupied hours.
For Bedrooms only – To guarantee comfort during the sleeping hours the operative temperature in the bedroom from 10pm to 7am shall not exceed 26°C for more than 1% of annual hours.
For rooms that are predominately mechanical ventilated a fixed temperature test must be followed.

All occupied rooms should not exceed an operative temperature of 26°C for more than 3% of the annual occupied hours.

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15
Q

What is a green / brown / blue roof?

A

A green extensive roof is planted for ecological and aesthetic purposes. Normally does not require as deep substrate as intensive. Requires less maintenance.

A green intensive roof is where typically bigger plants are grown and there is paving or decked areas. This requires deeper substrate.

A brown roof is where the planting is based on the original site had the building not been there.

A blue roof is onethatstoreswater, can include openwatersurfaces,storagewithin or beneath a porous media or modular surface or below a raiseddeckingsurface or cover.

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16
Q

How was the basement on your scheme going to be constructed?

A
  • Hoarding
  • Excavation - open and battened back
  • Secant wall piling installed (in fill piles are bored with the first set being a lower grade of concrete and these are not loadbearing and act as seals between the loadbearing piles.)
  • Concrete capping will be installed
  • Drained cavity and pump sump installed
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17
Q

What did you use instead of knauf?

A

Rockwool comfort board.

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18
Q

Why did you recommend a transfer slab/ changed column grid for One Woolwich?

A

This was because there was more uninterruptible space required on the ground floor and a transfer slab would require fewer columns.

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19
Q

In your documents you have highlighted the advantages/ disadvantages of Steel v Concrete. Could you talk me through some of these?

A
Steel
Advantages:
- Quicker to construct
- Recyclable
- Strong tensile strength
Disadvantages
- More volatile pricing
- Low compression strength
- Low sound/fire resistance
Concrete
Advantages
- High compression strength
- Good noise resistance
- Good fire protection
- Can mould into complex geometry
Disadvantages
-Slower to construct
- Need for reinforcement
- High embodied carbon
- Not as square and flat as steel
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20
Q

What are the types of piling?

A
Secant wall piling
Contiguous wall piling
Displacement
Replacement
Sheet piling
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21
Q

What are the types of curtain walling?

A

Stick system - assembled on site with each glazed element put together from either inside or outside, depending on accessibility.

Unitised - prefabricated in panels and delivered from off-site. Better quality due to factory quality control and quicker to assemble on site.

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22
Q

What are the 3 ways of waterproofing a basement under BS 8102?

A

Type A - Tanked protection,
Type B) - Structurally Integral Protection,
Type C) - Drained Cavity

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23
Q

What is basement tanking (Type A)- barrier protection?

A

A continuous waterproof barrier is applied to the inside or outside of the basement structure. The most common form is a bituminous ‘stick-on’ plastic sheet. Whilst this is relatively inexpensive, it can lose adhesion and is easily damaged during backfilling.

Alternatively, an external membrane can be painted or sprayed onto the external surface which can be covered by a drainage board to allow provide protection from the backfill.

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24
Q

What are Structurally Integral Protection basements (Type B)?

A

The structure itself is constructed as an integral water resistant shell. Invariably built of reinforced concrete, the basement structure must be designed within certain strict parameters to ensure it is water resistant.

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25
Q

What is a drained cavity basement (Type C)?

A

Cavities are formed between the internal and external wall and floor constructions to collect and drain away water entering the basement using a sump and pump. As well as the internal drain, a perimeter drain may also be included. This runs around the external perimeter of the building just below the level of the foundation, removing water from the building’s external face.

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26
Q

What are the risks with building basements?

A

Drainage difficulties and risks of flooding due to poor weather.
Poor ground conditions and natural ground heave or settlement.
Various obstructions, such as tunnels, existing services, mining works, archeological remains, and so on.
Boundary issues that may prove to be contentious, most commonly the foundations of nearby properties (see party wall act and right of support).
Loads from adjacent buildings and roads.
Failure of waterproofing, insurance and guarantees.

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27
Q

What level of noise protection did you need in your internal walls for imperial street?

A

The minimum level of airborne sound resistance for dividing walls or floors between homes is 45dB (decibels) in new builds and 43dB in conversion projects. This level should easily cut out normal levels of speech, TV and music playing.

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28
Q

What was the wall build up for a traditional handlaid brick wall in Clapham Park?

A

Brick, wall ties, cavity, insulation board, metal studs with mineral wool between, calcium silicate (sheathing board), 2 layers of plasterboard (1 vapour check and one fire resistant)

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29
Q

How are brick slip systems constructed? What is the typical cost?

A
Brick slips (aka brick veneers) can be laid as a form of cladding. Mortar (or a form of adhesive) is laid on the wall and bricks are spread in place, separated by spacers.
Alternatively, they can be installed in free standing panels (normally prefabricated) including other components such as insulation. This can then be anchored back to the structural frame.
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30
Q

What are the pros and cons of brick slip systems?

A

Advantages to using brick veneers:

They are relatively easy and quick to install.
They are not as heavy as other forms of masonry, which reduces structural loading.
Cavities behind external brick veneers can aid insulation.
They are durable and fire-resistant.
They can achieve a wide range of decorative functions
They require little maintenance.

Disadvantages include:
They are more susceptible to damage as they are thinner than conventional brick walls.
They do not contribute to structural integrity.
They can be susceptible to water damage.
Over time, the veneer will require re-pointing with new mortar.

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31
Q

How did UCL (part of CPD reading) achieve BREEAM outstanding using concrete frame?

A

Cornish Concrete could source china clay waste locally inthe Duchy and achieve 100% recycledaggregate in the structural precast. “The 50% GGBS content coupled with 100% secondary content aggregates meant each cubic metre of precast was 90% secondary sourced material,” says Moses.

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32
Q

What is build ability?

A

Buildability is a pre-construction exercise that assesses designs from the perspective of those that will manufacture, install components and carry out the construction works. This is in relation to:

  • Achieving the desired final quality;
  • Meeting the programme requirements;
  • De-risking perceived problems, and
  • Achieving optimum value for money.
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33
Q

What were the transfer slab grids used on One Woolwich before and after the change?

A

5 x 5 before which increased to 8 x 8.

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34
Q

Why was it more cost effective to use steel frame on the top floors?

A

Market tested rates were coming back slightly less than concrete (around £230/m2 compared to £270/m2), however the other benefits of steel including reduced foundations and quicker programme (reducing preliminaries) meant it was a more cost effective option.

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35
Q

Would using a steel frame on the top two floors affect buildability?

A

There would need to be more trades on site, however the sizes and spans on the top floors are very different to the below floors and if these were concrete, they would need to be constructed differently anyway.

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36
Q

What is a rain-screen cladding system?

A
A rainscreen (sometimes referred to as a ‘drained and ventilated’ or ‘pressure-equalised’ façade) is part of a double-wall construction that can be used to form the exterior walls of buildings.
Typically rainscreens are formed of relatively thin, pre-fabricated panels. The rainscreen itself simply prevents significant amounts of water from penetrating into the wall construction. Thermal insulation, airtightness and structural stability are provided by the second, inner part of the wall construction.
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37
Q

What materials are used for rainscreen cladding?

A

Rainscreen cladding can be fabricated from metal sheeting such as aluminium, stainless steel, zinc, copper and so on, or can be a formed from metal composite materials (MCM) which consist of two skins of metal (such as aluminium, or ACM) bonded to either side of a lightweight core such as polyethylene (PE) or polyurethane (PUR), a profiled metal core or a mineral core. Other materials, such as terracotta, brick slips, stone, timber and so on are also used.

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38
Q

How did the Grenfell tower’s facade contribute to the spread of the fire in 2017?

A
The ACM (aluminium composite material) rainscreen cladding fitted retrospectively to the original concrete facade had a gap between which allowed a chimney effect for the fire to spread.
The celotex insulation and cladding were both found to be flammable.
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39
Q

What is the Hackitt review?

A

An independent review of the building regulations related to fire safety. Dame Judith Hackitt was the CEO of the HSE.
The review looked at:
-The regulatory system around design, construction and on-going management in relation to fire safety.
-Compliance and enforcement issues.
-International regulation and experience in this area.

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40
Q

What did the Hackitt review find?

A
  • the roles and responsibilities of those procuring, designing, constructing and maintaining buildings are unclear;
  • the package of regulations and guidance can be ambiguous and inconsistent;
  • the processes that drive compliance with building safety requirements are weak and complex with poor record keeping and change control in too many cases;
  • competence across the system is patchy;
  • the product testing, labelling and marketing regime is opaque and insufficient; and
  • the voices of residents often goes unheard, even when safety issues are identified.
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41
Q

What did the Hackitt review recommend?

A
  • a new Joint Competent Authority (JCA) comprising Local Authority Building Standards, fire and rescue authorities and the Health and Safety Executive to oversee better management of safety risks of high rise residential buildings;
  • a set of rigorous and demanding roles and responsibilities for “duty holders” (i.e. building owners) to ensure a stronger focus on building safety;
  • a single, more streamlined, regulatory route to oversee building standards to ensure that enforcement can and does take place where necessary;
  • clearer rights and obligations for residents to maintain the fire safety, working in partnership with the duty holder;
  • a package of regulations that is simpler to navigate but genuinely reflects the level of complexity of building work; and
  • continuous improvement and best practice learning through membership of an international body.
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42
Q

How is composite metal cladding fixed to a steel frame?

A

 Bolted
 Riveted
 Welded.

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43
Q

What is screed?

A

A thin top layer of material (sand and cement) laid on to a floor surface to level it out.

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44
Q

What are the types of screed?

A
  • Bonded - laid to ready prepared rough, cleaned concrete base.
  • Unbonded - laid to sound, clean bitumen DPM.
  • Floating - laid with steel or fibre reinforcements to the insulating board which can be laid on to a suitable DPM.
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45
Q

What actions have been taken since the Hackitt review?

A

-A snap ban was introduced for combustible cladding on all buildings over 18m. This is likely to change to 11m. -There is also a proposal to introduce sprinklers to all buildings over 11m. The previous law was over 30m.

46
Q

What is the difference in volume for reducing the pile diameter and increasing the depth (on Clapham Park)?

A

This is volume neutral. The structural engineer confirmed both would be suitable to hold the building’s weight.

47
Q

What is CIBSE?

A

Chartered institute of building service engineers

48
Q

How is secant wall piling constructed?

A

Secant wall piling can be displacement or replacement piles. First, a shallow guide wall is formed using a formwork. Then concrete is poured in and the female piles are drilled/hammered in. After this, the male piles are secanted into the concrete. There will be excavation in the middle of the pile and this will need temporary propping/anchors.

49
Q

Is TM59 a national requirement?

A

Whilst these guidelines are not compulsory nationally, you may find the local council on your project asking you to follow them. TM59 provides a tool in which the control of overheating, ventilation, noise and air quality can be considered at an early stage in a project, with a consistent methodology to be applied across the industry and in a manner which future proofs against rising global temperatures.

50
Q

What was the impact to the cost when introducing transfer slabs on One Woolwich?

A

The overall price per m2 on the GIA increased from £250 to £270. The price of concrete was £180/m3. The price of reinforcement was £1200/kg.

51
Q

What is the cost difference between brick slip and traditional brick?

A

Traditional brick - full wall build up (£450-500/m2). Brick slip - full wall build up (£550-£650/m2).

52
Q

What is gebrick?

A

This is a type of panel which has brick slips attached to it. Is a prefabricated material used for facade construction.

53
Q

How did the external wall build up differ with the 3 options (brick slips with gebrick, precast panel and brick and traditional brick)?

A

The brick slip with gebrick is a prefabrication whereby a cut out of a brick is attached to rainscreen board and an inner sheathing board. There is then an insulation board, cavity and 2 layers of plasterboard.
The precast panel had brick bonded to the RC Precast panel, insulation layers, Vapour control layers, mineral wool insulation, metal studs and 2 layers of plasterboard.
The traditional brick wall had brick, cavity, insulation, and metal stud/block work with 2 layers of plasterboard.

54
Q

How did preliminaries costs vary with the different facade construction?

A

As advised by the mace planning team, I was able to estimate the cost per week for preliminaries and adjust the cost accordingly to their timescale suggested. This also meant that scaffolding costs could be reduced.

55
Q

Regarding the value engineering of the concrete to steel frame, what did it reduce the foundation size to and how did you establish this was ok, what was the cost saving?

A

The foundations were able to reduce from 600mm diameter to 450mm diameter piles whilst keeping the same depth. This meant the cost per pile reduced in terms of volume of concrete and reinforcement.

56
Q

What is considered a modern method of construction?

A

Panellisedunitsproduced in a factory andassembledon-siteto produce a three-dimensionalstructure.

Volumetric constructionto produce three dimensionalmodularunitsin controlled factoryconditionsprior totransporttosite.

Hybrid techniques that combine both panellised andvolumetricapproaches.

Floororroofcassettes, pre castconcretefoundationassemblies, pre formedwiringlooms, mechanicalengineeringcompositesandinnovativetechniques such astunnelformor thin-jointblockwork.

57
Q

What are the benefits of modern methods of construction?

A

It should be possible tobuildup to four times as many homes with the same on-sitelabour.

On-siteconstructiontime could be reduced by more than half.

Building performancecould be at least asgood.

Costranges would be comparable depending on specificprojectcircumstances, although they would be higher on average.

Risksincreased at early stages of thedevelopment processsogoodrisk managementwould become even more important.

Tight liaison withplanning authoritieswould be vital.

Benefits would be wasted ifprojectswere not properly planned

58
Q

What are criticisms of modern methods of construction?

A

TheBuildingAlliancesuggested that thematerialsandsystemsadoptedbymodern methods of constructionare almost exclusively imported and this will; “…undermineinvestmentin BritishManufacturedmasonryproductsthat are preferred byconsumers,costsome 15% less, are non combustibleand flexible and arebuiltto last 150 years.”

  • Getting accreditation for pods and insurance
  • Difficulty in getting BOPAS
59
Q

What ways can buildings be mechanically ventilated?

A

On residential project, generally MVHRs are used. These are energy recovery ventilation systems that use air-to-air heat exchangers that recovers heat that is usually wasted. It works by supply

60
Q

What basement type was used on Imperial Street?

A

This was a combination of type A, B and C basement and was a grade 3 basement. This meant the walls were waterproofed (type A), the walls were waterproofed (type B) and there was a drained cavity?

61
Q

What was the build up to the basement wall?

A

Secant wall piling, wall cavity, internal block wall, waterproof layer, 2 layers of plasterboard

62
Q

What is a shelf angle in terms of masonry support?

A

A shelf angle is a structural steel member that transfers the dead load of the brick back to the building frame. An expansion joint should be placed to prevent cracking.

63
Q

What was the cost difference per pile when reducing the diameter from 600mm to 450mm?

A

The market tested rates came back at £1.4K/pile for 600mm diameter 20m piles and £1.3k for 450mm piles.

64
Q

What are the different options for retaining walls?

A

Retaining walls are structures designed to retain material to one side to prevent collapsing, slipping or erosion. Options can include:

  • Gravity (made of stone, concrete or brick)
  • Sheet piling (made of interlocking steel, timber or vinyl panels)
  • Reinforced retaining wall (stability of the wall can be increased from reinforcement bars which are connected to the slab foundation)
65
Q

What is a diaphragm wall?

A

This is a structural concrete wall constructed in deep trench excavation, normally on congested sites, close to existing structures, where there is restricted headroom or where the excavation is of a depth that would otherwise require the removal of much greater volumes of soil to provide stable battered slopes.

66
Q

Why was a diaphragm wall not considered?

A

The basement was a single storey and the diaphragm wall posed a high cost due to the nature of the construction where very large cutters are required to pour concrete in panels which are tied together with ground anchors.

67
Q

Why use secant wall piling and not contiguous?

A

Secant wall piling generally reduces the chance of water entry into the basement.

68
Q

What are the best facade options for low rise and why?

A
  • Traditional brick is cheap

- Less weight issues as building is low rise

69
Q

What are the best facade options for low rise and why?

A
  • Traditional brick is often used because of the performance, durability, low maintenance and cost. However, there are some weight implications when building at height.
  • Loadbearing brick is also used for similar reasons.
70
Q

What is a lightweight alternative to precast concrete?

A

GRC - glass fibre reinforced cement cladding panels. Big weight savings as compared to precast concrete and can be formed in a variety of shapes.

71
Q

What are other types of lightweight cladding?

A

Rainscreen

72
Q

What is a sheathing board?

A

In the construction industry, the term ‘sheathing’, or ‘sheathing board’ can be used to refer to a layer of board or panel material that forms a part of floor, wall and roof assemblies. The outer sheathing board strengthens the assembly, provides a surface for other materials to be applied to and may give some degree of weather resistance.

73
Q

What is corium brick slip cladding?

A

A brick slip system which uses a vertical rail system to attach the bricks to. Typically costs around £700/m2 for a through wall construction.

74
Q

What material is gebrick attached to and how?

A

In the factory, the brick slips are laid in a mould, they are then covered with quartz sand and liquid polyurethane (an expansive insulation material) is poured over the brick slip to bind the materials together. The brick slip panel can then be

75
Q

What is the recent discussion on laminate balustrade?

A

Although laminate is not combustible, the inter-layer used to make it laminate is combustible. I would recommend perforated metal balustrade.

76
Q

Where would you find sprinklers?

A

Sprinklers would be found in residential units however not in circulation spaces.

77
Q

You mention you have experience with traditional brick facades with metsec. Can you explain the construction sequence of this type of construction?

A

Concrete frame will be complete. The SFS will be placed in between each slab, the bricklayer will then be able to start on the ground floor and work his/her way up also installing the insulation, calcium silicate board (or sheathing board), any cavity trays (around windows) brick ties (or metal sheeting to attach to slabs), 2 layers of plasterboard.

78
Q

You mention that you suggested the reduction of the pile diameter 600mm 15m to slender piles 450mm 20m deep. a. What was the basis of this suggestion?

A

I came about this idea as on a previous project this option was proposed by a specialist subcontractor who suggested it was structurally integral. I then contacted them for market testing and was able to share the design of this project for them to make an assessment. They were able to confirm it was structurally integral as well as the structural engineer. This option was able to save cost bringing the cost per pile from £1600 to £1500 despite the same volume of concrete, the fact that there were more subcontractors able to provide this pile depth meant there was more competitive prices.

79
Q

You mention that you have an understanding on the different choices of facades that can be used for high rise and low buildings. Please explain which facades are commonly used in both cases and why.

A

In Low rise facades, traditional brick is typically used because of the lower cost and the less need for the construction to be lightweight. This is either loadbearing masonry or a frame construction with brick and block.
In high rise, a framed solution with either brick or a cladding with SFS is often used because this is a lighter weight compared to traditional brick and block. If a cladding is chosen, there is not the health and safety risk of building scaffolding at height. A traditional loadbearing brick wall would also not be structurally possible at high rise.

80
Q

Why did you recommend steel on the top 2 floors on this project? If steel was cheaper why not use it on all floors?

A

The design team were able to confirm a 10% reduction in piles. As the steel frame was only on 2 floors, the steel columns and beams were slimmer than they would be for the whole building being steel and this meant they were cheaper. The top 2 floors were also recessed which included a different design and layout with a large terrace to the below concrete floors.

81
Q

What are the different types of scaffold?

A
  • Mast climbers

- Traditional scaffold

82
Q

What did you discuss with the precast contractors?

A
  • Cost implications for installing windows on precast panels
  • Special design features
  • Effect of prelims compared to traditional methods ( no need for scaffold)
83
Q

What do the GLA state regarding units per core?

A

According to the GLA this should not exceed 8 residential units per core.

84
Q

Why were the 450mm piles less than the 600mm piles?

A

The availability of the pile rigs

85
Q

What is the Difference Between a Cat A and Cat B Fit Out?

A

In short, a Cat A fit out results in a space that’s fully functional, but empty. Cat B fit outs leave the space tailor-made to suit the occupant, from custom features to branded finishes – down to the flowers at reception.

Category A (Cat A) generally describes the level of fit out that the tenant’s own space is completed to by the developer. There is no standard definition, but a category A fit out may include.

Raised floors and suspended ceilings.
Distribution of mechanical and electrical services.
Internal surface finishes.
Blinds.

Category B (Cat B) completes the fit out of the internal space to the tenant’s requirements. This may include:

Final finishes and branding.
Installation of offices.
Installation of specialist facilities in meeting rooms, board rooms conference rooms, and so on.
Fitting out reception areas.
Installation of specialist lighting.
Installation of ICT equipment.
Installation of audio visual equipment.
Fit out of kitchen areas.
Installation of furniture.
86
Q

What are the different types of replacement piles?

A

Bored piles are drilled using buckets and/or augers driven by percussion boring (vibratory hammers) or through rotary boring (twisting in place).

In unstable soil strata, the use of bentonite fluid assists in stabilising the bore especially in large diameter deeper piles and allows the insertion of heavily reinforcing steel cages. This is known as flush boring.

If the boring and pouring takes place simultaneously, piles are known as continuous flight auger (CFA) piles.

87
Q

Why would you use bored piles instead of CFA?

A
  • Rotary bored piles are often larger diameter than conventional continuous flight auger (CFA) piles. They are used to support greater loads, overcome underground obstructions and to penetrate ground too hard to bore using continuous flight auger techniques. Rotary pile installation can also be used to create piles with a cut-off level beneath the platform level. Because the rotary bored technique enables the reinforcement to be added into the open bore rather than into the ready poured concrete, as in CFA, it has the distinct advantage of allowing the cage to be the full depth of the pile.
88
Q

Why our cavity trays becoming more expensive?

A

Cavity trays now need to be stainless steel so they are non-combustible.

89
Q

What is the curtain walling where there is a slab in the wall?

A

Spandrel panel

90
Q

What is an inverted roof ?

A

An inverted roof, or upside down roof, places the
insulation on top of the waterproof membrane and
is popular for flat roof construction. Paving slabs or
decking can be used to protect the insulation and
provide a surface to walk on, but also prevent the
wind lifting the insulation.

91
Q

What is a cold roof?

A

A cold roof or cold deck roof places the insulation
onto or immediately above the ceiling and below the
roof deck. Traditional houses with pitched roofs and
lofts are a good example, but flat roofs have also
been designed in this way. There is a risk, however,
that moist air will condense on the underside of
the roof covering and within the void itself, so it
is important that the void above the insulation is
ventilated. It is also possible to fit a vapour control
barrier beneath the insulation. Because of the
difficulties of ventilating cold deck flat roofs, they are
often converted to warm deck roofs.

92
Q

What changes have been made to the building regulations regarding cladding?

A

On 1 October 2018, the government confirmed that it would ban the use of combustible materials on the external walls of high-rise residential buildings. The ban is to also apply to hospitals, care homes and student accommodation over 18 m-tall. (Hotels and office buildings are to be exempt due to their different evacuation strategies and lower risks.)

93
Q

What is a warm roof?

A

A warm deck roof, or sandwich roof, places the insulation above the roof deck and below the line of the covering. A vapour control layer is placed between the deck and the insulation. The waterproof covering is placed on top of the insulation.

94
Q

What were the key components associated with the cranage usage on St Leonards?

A
  • Hire rate
  • Oversailing costs
  • Temporary structure
  • Crane driver
  • Delivery to site.
95
Q

Did you have ground beams in your project (Clapham Park)?

A
  • Yes, these were used to connect different pile caps and were place where external wall was.
96
Q

What was the cost of scaffolding on your project and what type was it?

A

-Typical cost £35-60/m2 for traditional scaffolding.

-

97
Q

What was the impact on programme of the scaffolding option?

A

A mast climber option was not considered due to the extra cost. However this would have saved time.

98
Q

Who are the different precast suppliers?

A
  • Thorpe

- Techrete

99
Q

What is fire compartmentalization?

A

The spread of fire can be restricted by sub-dividing buildings into a number of discrete compartments. These fire compartments are separated from one another by compartment walls and compartment floors made of a fire-resisting construction which hinders the spread of fire.

100
Q

What are the different types of rainscreen cladding?

A

There are two basic types of rainscreen:

  • Drained and ventilated rainscreen cladding systems allow any penetrating moisture to drain or evaporate and vent to the outside. In this case it is necessary to detail the façade so that any penetrating water cannot cross the gap between the rainscreen and the internal wall construction.
  • Pressure-equalised (PE) rainscreen cladding systems allow the movement of air between the inside and outside of the rainscreen. This equalises the pressure across the rainscreen so that water is not driven, or sucked through the joints.
    The difference between the two systems relates to how much water can penetrate the joints, with drained and ventilated systems allowing more water to penetrate. However, the definitions are relatively vague, and the distinction has become somewhat blurred.
101
Q

What are recent changes to building regs?

A
  • Fire safety - no combustible material in buildings above 18m. Recent article to change to 11m for combustible material defined by British Standards A1 A2, B.
  • Sprinklers in buildings above 11m
  • Responsible person (property manager) to manage the fire safety in blocks.
102
Q

What is a party wall?

A

A party wall is the shared wall, usually between a terrace or semi-detached house, and divides the homes of two separate owners.

103
Q

What is the rights of light?

A

Generally, a right to light refers to the right to receive sufficient light through an opening (such as a window), allowing ‘ordinary’ comfortable use and enjoyment of a dwelling, or ‘ordinary’ beneficial use and occupation of other buildings.

104
Q

What are the different types of heat source?

A
  • CHP plant room (HIU regulates heat into units).
  • Boilers
  • Air source heat pump
  • Ground source heat pumps
105
Q

What is the difference between MEV and MVHR?

A

Mechanically ventilated heat recovery.
Mechanical extract ventilation

MVHR offers a completely balanced system, providing both extract and supply ventilation. It extracts heat and moisture from wet rooms/kitchens and supplies fresh, filtered air, including recovered heat, to habitable rooms. MEV is also a whole house ventilation system but provides just extract ventilation from wet rooms and kitchens.

Both MEV and MVHR systems are most suitable for new properties rather than retrofit, but MVHR systems do require a more airtight property where virtually all of the air flow can pass through the heat exchanger, if they are to perform efficiently.

With inner cities obviously having higher pollution levels, MVHR systems are seen as more suitable because of the filter element, but in apartment blocks it’s often the case that only the first four floors are fitted with MVHR and the remaining with MEV as polluted air is heavier and therefore stays closer to the ground.

106
Q

What is a BMS?

A

Building management systems are computer-based systems used to monitor and control building services such as:

Lighting.
Heating, ventilation and air conditioning (HVAC).
Fire, smoke detection and alarms.
Motion detectors, CCTV, security and access control.
ICT systems.
Lifts.
Industrial processes or equipment.
Shading devices.
Smart meters.
107
Q

What is the difference between inert and hazardous?

A

Inert waste is waste which is neither chemically nor biologically reactive and will not decompose or only very slowly. Examples of this are sand and concrete. This has particular relevance to landfills as inert waste typically requires lower disposal fees than biodegradable waste or hazardous waste.

108
Q

What is asbestos?

A

A fiberous material used for insulation.

109
Q

What is a WAC test?

A

Waste acceptance criteria. Categorizes waste into hazardous, non-hazardous or inert.

110
Q

What are MMCs?

A

MMC is a term used in the construction industry to describe new technologies that improve the requirements of speed, quality and reliability on site. In the main, these systems are manufactured off-site under a dry roof in factory style conditions or by newer on-site technologies. The off-site products are then normally delivered to site by lorry and craned into position. The size of the element is often determined by the size of our roads or the difficulties encountered in accessing the site, such as bridges and tunnels. Although some systems are imported, many are manufactured in the UK.

111
Q

What are the types of air conditioning?

A
  • Fan coil unit - supplies air conditioning within a building using hot and cold water depending on time of year
  • Chilled beams - Pipes of water are passed through a “beam” (a heat exchanger) As the beam chills the air around it, the air becomes denser and falls to the floor.
  • VRV/VRF systems heating and cooling or heating/cooling. Ductwork to transfer heat or cooling around building.
112
Q

What components made up the steel frame on Pines way?

A

Steel beams, steel columns and steel decking.