Construction Technology (Master) Flashcards
Please explain how pre-cast concrete panels works?
- Pre-cast concrete panels are made up of precast concrete faced with bricks
- Glazing assemblies (windows) are incorporated off site to create a story high modular cladding panel.
- Each cladding panel is dead loaded at it base to the concrete slab and fixed to the slab above
- Fire stops are installed at slab edge
- Pre-cast panels overlap to hide vertical joints that retain brick aesthetics
Elements (looking from the face of slab/structural column): Vapour control panel, mineral wool insulation, fire stopping (fixed to the structural column, Precast concrete panel, double glazed unit, brick facing
Please explain how the glazing curtain wall works?
- Glazing curtain wall is made of aluminium frame with double glazed unit.
- Glazing clips are used to restrain the glass on vertical edge and structural silicone is used on the horizontal edge
- Mullions are incorporated into the panel to dived unit in half as per design
- External shading louvres are fixed back to mullions via stainless stell support brackets
- Fire stops at the edge of the slab
Elements: aluminium frame, double glazed unit, shedding louvres, mullions.
Please explain what Aluminium rainscreen is made of?
- Aluminium rainscreen is fabricated from aluminium sheeting panel that are fixed to the vertical support rial in the lower joint between panel.
- Air cavity/ Ventilation zone is created between the cladding panel and concrete backing wall.
- Insulation layer (mineral wool insulation and water proof membrane) is installed between the concrete backing wall and air cavity/ventilation zone.
Elements (from concrete backing walls): water proof membrane mineral wool insulation, Vertical aluminium support rail, Air cavity/ ventilation zone, aluminium cladding panel.
What is a roof lantern?
- Roof lantern is made of several glasses fixed together to create a £D shape; can be pyramid or box that raises above the roof.
- This is a daylighting architectural element, which is normally part of a larger roof allowing natural light into the space/room
What are the Roof lights?
Rooflights (sometimes described as ‘roof lights’ or ‘skylights’) are windows built into the roof of a building.
What is the difference between the roof light and roof lantern?
- shape: roof light is flat (2D dimension) whereas roof later is of the 3D pyramid or box shape
- design: due to 3D shape roof lantern provide more natural lights or ventilations
- Installation: roof lantern installation is more difficult and impact on overall cost.
- cost: Roof lantern are more expensive than roof lights due to the shape, glazing area and difficulties in installation (nearly 300% cost increase at PW)
What are the advantages and disadvantages of roof lantern?
Advantages:
- Design: They add a visually attractive element to the building
- Lighting: Providing natural light
- Size: Lanterns can be built bigger overall since you have smaller pieces of glass that are connected with plastic or aluminium frames
Disadvantages:
- Solar natural warmth can lead to an increase in room temperature and additional cooling may be required
- Difficult to maintain – cleaning is difficult
- Higher cost material and installation cost when compared to flat roof lights due to size and difficulty of installation
How did you advice the Client about roof lights element on PW?
- During Stage 4 Design, I took part in monthly design meeting where the Design Team introduced the new design changing the roof light to roof lantern.
- I reviewed the Client’s briefing and scope documents to ensure that the proposed solution is in line with Client’s requirements
- I reviewed previous drawings and BIM model and identify Stage 3 Cost Plan allowances (30
- I reviewed new drawings, measured the rooflights and priced the new design.
- I produced short report summarising the change and its implication.
- I attended meeting with the Client where we discussed the change its aesthetics and I explained the cost difference.
What is a lift car?
Lift car is a cabin which transport passages or goods between the levels of building.
Can you name any regulations related to Lifts?
- The Lifts Regulations 2016 – obligations of installers, manufactures, distributes etc.
- The Lifting Operations and Lifting Equipment Regulations 1998 (LOLER) - provide guidance on lifts used by workers in workplaces. It requires lifts to be thoroughly examined by a competent person at least every six months or, in the case of goods-only lifts, every 12 months.
- Provision and Use of Work Equipment Regulations 1998 (PUWER)
- Approved Document M - Access to and use of buildings
- The Equality Act 2010, requires that buildings must be accessible to people with disabilities. BS 8300 recommends that multi-storey buildings provide at least one accessible lift for wheelchair users.
- There are a number of British Standards that apply to lifts:
- BS EN 81, Safety rules for construction and installation of lifts.
- BS 5588, Fire precautions in the design, construction and use of buildings.
What are the main components of lift?
- Lift car cabin
- The Sheave and Motor
- Control unit
- Cable/Rope
- The counter weight
- Hoistway
What types of lifts are you awere of?
- Platform lifts
- Passenger lifts
- Service lifts
- Disable access lifts
How lifts works?
- Lift car/cabin is connected by metal robe/cable into sheeve/pulley wheel
- The sheeve/pulley wheel allow the lift car to be move up and down and it’s powered by lift motor with counter weight used to balance the car lift weight.
How did you advice the Client regarding lift car finishes options on NCA Project?
- I reviewed the Client’s brief for a change
- I discussed potential options with the Design Manager to proposed best option
- I measured relevant quantities (GIFA for floor and lift wall area) and provided a budget estimate for each option.
- I provide a report summarising two options in terms of key features and cost differences
- I presented information to the client advising on differences of both options (vinyl and laminated wood panels) in comparation with stainless steel design currently in the scope.
What are the differences between laminated wooden, vinyl and stainless steel materials?
1. Vinyl
- Budget friendly (average £20 to £50/m2)
- Durability 15 to 20 years
- Water and stain resistant
- Difficult to repair
2. Laminated Wooden
- Average costs £30 to £60/m2
- Durability 10 to 30 years
- Environmentally-friendly construction material
- High strength to weight ratio
- water and stain resistance
- improved aesthetics
3. Stainless steel
- Average cost £20 to £40
- Durability 15 to 25 years
- water resistance
- easy to maintain
- design flexibility
What type of wood was used for finishes on NCA?
laminated oak panels.
What does it mean to wood is laminated?
A wood laminate is a thin sheet of material used to cover the core of a wood project in order to change the appearance of the material.
What do you need to consider when design a lift finishes?
- Fire resistance
- Weight of materials
- Feasibility and accessibility
- if there is CCTV/phone/speakers required
- relevant regulations and standards (BS)
What is an average cost of lift?
- depending on the design specifics, most of the lift’s are bespoken as they may be design for different heigh and capacity as well as type of lift.
- On NCA Project the cost was £100k per 13 people lift, £90k for 8 people lift and £15k for platform lift.
What is mullion?
Mulion is a a vertical bar between the panes of glass in a window that dividing the window.
What is a A Vapour Control Layer?
A Vapour Control Layer is a plastic layer that restricts the movement of warm, moist air from inside a property into the fabric of the building
What are the External shading louvres?
The external louvres are blinds or shutters with horizontal slats that limit a solar exposure, but still allow light.
What are ground investigation?
Ground investigations are a means of determining the condition of the ground, ideally before beginning construction works. They focus specifically on intrusive geotechnical work such as trial pits and boreholes
What is a site investigation?
- Site Investigation is the process of collecting information, assessment of the data and reporting potential hazards about the site which are unknown.
- tend to involve the collation of general information from the client, from desk studies, walkover surveys, and so on.
What can be determinated by a ground investigation?
- Detailed information about soil and ground samples
- Water table level
- Contaminations
- Obstructions (e.g old foundation)
- archaeological fundings
What information were included in Factual Site Investigation Report?
- General project information’s
- Project descriptions and scope of works including drawing
- Site investigation methodology and locations (percussion boring, rotary drilling, trenches, PAS 128 Survey, Drainage CCTV survey, Archaeological) including detailed information of sampling methods
- Percussion boring and rotary drilling log (depth of the borehole, detailed progress with dates ad hole depth), strata information with soil description, samples and tests.
- Description of Archaeological desk top study – analysis of previous site uses,
- Photographs
- PAS 128 results in form of map with marked up utility services.
- Laboratory tests results
What is CCTV drainage?
A CCTV drainage survey is a process for examining the condition of drainage systems remotely with a camera system that records video footage and captures other useful data
What is PAS 128?
British Standards Institution (BSI) PAS 128 is the current specification for underground utility detection, verification and location
For level of investigation include:
- Level A - Instrusive inspection
- Level B - Detection using GPR and other geophisical techniques.
- Level C - Validation of existing record
- Level D - Desktop locating services
How did you assess progress of ground investigation works?
- On site visit and visual assessment of location of the boreholes
- Analysis of weekly ground investigation report where completed works were analysed by geotechnical engender
- Analysis of contractor site diary and progress made.
- The measurement included within CE for this work was based on UK Specification for Ground Investigation published by ICE (Institution of Civil Engineering) and in line with Section Class B therefore my assessment was based of the depth of the borehole in addition to time related assessment of the time spend by the team
- I measured each element based on time and work progress.
- I issued my assessment to the PM for their comment
- I advised the Client on costs associated with work completed and included the calculation when issuing the Payment Notice with basis of my afp assessment.
On the Project Winchester, what were the key considerations on
the assessment of the differing façade treatment?
- Quality – diverse façade improved quality of the design as different styles was incorporated (e.g pre-cast concrete and glazing wall)
- Cost – implementation of different facade treatment allowed to incorporate cheaper type of façade (aluminium rainscreen) to clad utility areas of the building which are less visible to the public.
- Time – incorporation of pre-cast concrete panel façade had positive programme implications as they were made off site.
What is percussion boring?
- Percussion boring is method of ground investigation, where percussion drill repeatedly raises and drops a large hammer bit onto hollow tube.
- The hollow tube then accumulate soil for sampling. Then the sample hollow tube is lifted by the cabling system and the sample is being tested
- A single day drilling can excavate up to 15m (typically 7-15m)
- Standard penetrometer test (SPT) and vane test can be carried out in the borehole as the drilling and excavation process progress.
What is rotary drilling?
- Rotary drilling uses a sharp rotating drill rig and downward pressure to cut through the surface.
- The drill bit/auger is then removed to allow for sampling (hollow tube is placed in the hole).
- The hollow tube is then twisted into the ground to collect the sample.
- The process is repeated gain at different ground level if any further testing is required.
What are trenches?
- Trenches or Trial pits is an excavation of an area of ground in order to study or sample the composition and structure of subsurface.
- use to determine the geology and the water table of the ground.
What types of ground investigation tests and sampling were carried out on PW?
- Moisture content
- pH value test - is done to see how acidic or alkaline your soil is
- Permeability testing
- Contamination testing
- CBR test (California Bearing test) - The CBR test is performed by measuring the pressure required to penetrate a soil sample with a plunger of standard area.
What is a listed building?
A building is listed when it is of special architectural or historic interest considered to be of national importance and therefore worth protecting.
What are the different type of building being listed?
- Grade I: This means the property is of ‘exceptional interest’. Only around 2.5% of listed buildings are Grade 1 listed.
- Grade II*: This means the property is important and considered of more than special interest. Around 5.8% of listed buildings fall into this category.
- Grade II: This means the building is of special interest. The vast majority of listed buildings (around 92%) fall into this category.
What are the consequences of building being listed?
- You will need our consent to demolish a listed building and for any alteration or extension which would affect its character as a building of architectural or historic interest.
- The need for listed building consent is different from planning permission but the process is very similar.
- It is a criminal offence not to seek consent when it is require
- An application for listed building consent is made to, and determined by, the local planning authority
How rainscreen cladding works?
Rainscreen cladding work by creating a ventilated cavity zone/gap between the reveres of the cladding panel and the outer face of the building,
This enables constant air circulation, forcing any moisture that penetrates the joints of the cladding panels out, before it reaches the building structure.
In addition, the waterproof membrane is normally installed into the backing wall to increase the water resistance.
What are the types of rainscreen?
- Drained and ventilated rainscreen cladding systems allow any penetrating moisture to drain or evaporate and vent to the outside.
- 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.
What are the key stages of the RIBA plan of work?
0. Strategic Definition – confirmation of Client’s Requirement
1. Preparation and Brief – Project Brief is approved by the Client and confirmed that it can be accommodated on site
2. Concept Design – Architectural Concept approved by the Client and aligned to the Project Brief
3. Spatial Coordination – Architectural and engineering information Spatially Coordinated.
4. Technical Design – all designed information required to manufacture and construct the project completed
5. Manufacturing and Construction – manufacturing, construction and commissioning completed
6. Handover – building handed over, aftercare initiated, and Building Contract concluded
7. Use – building used, operated and maintained effectively.
What was included in the 2020 update?
- Some stages re-named (Stage 1 was Preparation and Brief but has been renamed Preparation and Briefing; Stage 3 was Developed Design – it’s now Spatial Coordination; Stage 5 was Construction and is now Manufacturing and Construction; Stage 6 was Handover and Close Out and is now just Handover; and Stage 7 was gone from In Use to Use.
- Stage 5’s new name reflects the increasing popularity of modular and prefabricated construction.
- The importance of sustainability is highlighted - For the first time the RIBA Plan of Work includes a Sustainability Project Strategy
- and different approaches to the timing of planning applications and procurement.
How did the Grenfell tower’s facade contribute to the spread of the fire in 2017?
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.
What RIBA stands for?
The Royal Institute of British Architects
What is RIBA Plan of Works?
The RIBA Plan of Work organises the process of briefing, designing, constructing and operating building projects into eight stages and explains the stage outcomes, core tasks and information exchanges required at each stage.
What are the alternative to RIBA?
- The BIM Task Group Digital Plan of Work (0- Strategy, 1- Brief, 2- Concept, 3-Definition, 4-Design, 5- Build and commission, 6- Handover and close out, 7- Operation and end of life)
- The Construction Industry Council (CIC) – Stage 1 – Preparation, Stage 2 – Concept, Stage 3- Design Development, 4 – Production Information, Stage 5 - Manufacture, Installation & Construction Information, Stage 6 – Post Practical Completion
- The Construction Playbook: Preparation and planning, Publication. Selection. Evaluation and award. Contract implementation.
What is RIBA Stage 0?
Stage 0 – Strategic Definition is about determining the best methods of achieving the client’s requirements.
Strategic in nature, defining the Business Case and Client Requirements.
What is RIBA Stage 1?
Stage 1 (Preparation and Briefing )is about developing the detail of the brief and making sure that everything needed for the design process is in place before Stage 2. This includes ensuring that the brief can be accommodated on the site.
- Feasibility Studies
What is RIBA Stage 2?
Stage 2 (Concept Design) is about getting the design concept right and making sure that the look and feel of the building is proceeding in line with the client’s vision, brief and budget.
What is RIBA Stage 3?
The purpose of Stage 3 (Spatial Coordination)is to spatially coordinate the design.
- Undertake Design Studies, Engineering Analysis and Cost Exercises to test Architectural Concept resulting in Spatially Coordinated design aligned to updated Cost Plan, Project Strategies and Outline Specification
- Initiate Change Control Procedures
- Prepare stage Design Programme
What is RIBA Stage 4?
During Stage 4 (Technical Design) stage - All design information required to manufacture and construct the project completed
- Develop architectural and engineering technical design
- Prepare and coordinate design team Building Systems information
- Prepare and integrate specialist subcontractor Building Systems information
- Prepare stage Design Programme
What is RIBA Stage 5?
Stage 5 is Manufacturing and Construction where all on-site works are being completed.
- Finalise Site Logistics
- Manufacture Building Systems and construct a building
- Monitor progress against Construction Programme
- Inspect Construction Quality
- Resolve Site Queries as required
- Undertake Commissioning of building
- Prepare Building Manual
What is RIBA Stage 6?
Building handed over, Aftercare initiated and Building Contract concluded.
- Hand over building in line with Plan for Use Strategy
- Undertake review of Project Performance
- Undertake seasonal Commissioning
- Rectify defects
- Complete initial Aftercare tasks including light touch Post Occupancy Evaluation
What is RIBA Stage 7?
Building used, operated and maintained efficiently
- Implement Facilities Management and Asset Management
- Undertake Post Occupancy Evaluation of building performance in use
- Verify Project Outcomes including Sustainability Outcomes
How a load is transferred through the piles into the ground?
Tow main methods of transferring the load depending o the piles’ type:
End-bearing piles – the bottom of the pile rest on a layer of especially strong soil or rock. The load of the building is transferred through the pile onto the strong layer; this pile act as a column.
Friction (or floating) – the pile transfers the load of the building to the soil across the full heigh of the pile, by friction; the entire surface of the pile works to transfer the forces to the soil.
What different types of buildings loads are you aware of?
- Dead loads refer to the structure’s self-weight and generally remain constant during the structure’s life.
- Live loads, such as traffic loads may vary.
What is a dead load?
Dead loads, also known as permanent or static loads, are those that remain relatively constant over time and comprise, for example, the weight of a building’s structural elements, such as beams, walls, roof and structural flooring components
What types of piles do you know?
- based on material: steel, concrete and timber
- based on transfer load: End bearing piles, fraction piles and combined
- based on the method of installation: driven piles, driven cast in-situ piles, screw piles, secant pile
What are the End bearing piles?
End-bearing piles – the bottom of the pile rest on a layer of especially strong soil or rock. The load of the building is transferred through the pile onto the strong layer; this pile act as a column.
The pile transmits the load to the surrounding soil by adhesion or friction between the surface of the pile and the soil. In this case, the whole surface of the pile works to transfer the load to the soil.
What are the friction piles?
Friction (or floating) – the pile transfers the load of the building to the soil across the full height of the pile, by friction; the entire surface of the pile works to transfer the forces to the soil.
What are the driven piles?
Driven piles, also known as displacement piles
A driven pile is a long, slender column made of steel, precast concrete, timber or composite and having a predetermined shape and size that can be installed by impact hammering, vibrating or pushing it into the ground to a design depth or resistance.
How driven piles are installed?
A pile hammer is used to drive piles into the ground and that can be installed by impact hammering, vibrating or pushing it into the ground
Advantages and disadvantages of driven piles?
Advantages:
- Time and material efficiency – piles can be prefabricated off-site
- A wide variant of material available so flexible in terms of shape
- Great structural strength to other forms of foundation
- Installation usually produces little spoil for removal and disposal.
Disadvantages:
- planning is required for handling and driving
- Heavy equipment on site
- Not be suitable where the ground has poor drainage qualities.
- may not be suitable for compact sites, where other foundations nearby
- Noisy to install and vibration
What are driven cast in situ piles?
Driven cast in-situ (DCIS) piles are constructed by driving a closed-ended hollow steel or concrete casing into the ground and then filling it with concrete.
How are driven cast in situ piles installed?
Driven cast in-situ (DCIS) piles are constructed by driving a closed-ended thick-walled steel casing into the ground and then filling it with concrete.
Advantages and disadvantages of the driven cast in situ piles?
Advantages
- Flexibility - Piles of any size and length may be constructed at the site.
- Easy to transport
- Familiarity – common to use on construction sites and no serious skilled required
- Noise and vibration are minimal with little impact on neighbouring properties
Disadvantages
- careful supervision and on-site quality control required
- storage for materials on-site needed
- It can take more time to form a cast-in-situ pile
- There are large amounts of spoil to be removed from the site.
What are screw piles?
- Screw piles are a steel screw-in piling and ground anchoring system used for building deep foundations
- can be installed quickly with minimal noise and vibration.
- Screw piles are wound into the ground, much like a screw is wound into wood. Screw piles cut into the soil following a constant pitch, as opposed to auguring through it.
How secant piles are installed?
- Secant piles are formed by constructing reinforcement concrete piles that interlock.
- Typically primary (female) piles are cast in leaving space between them. this is followed by secondary(male) piles being cut into the primary piles to form a continuous wall (with a typical interlock of 150 mm)
- normally reinforced with steel rebar or steel beams.
What are the main components of concrete?
Cement, aggregate, water
What are the most common types of the frame?
- Concrete - concrete frames can be pre-cast off site under factory condition or cast in situ prepared framework
- Steel – steel frames are fabricated off site before being brought to the site and erected there
- Timber – timber frames are fabricated off sire using solid sections or are panelised
What is contiguous piling?
A line of non-interlinked piles in a sequence
In your documents you have highlighted the advantages/ disadvantages of Steel v Concrete. Could you talk me through some of these?
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
- more flexible in shape
Disadvantages
-Slower to construct
- Need for reinforcement
- High embodied carbon
- Not as square and flat as steel
What are the types of curtain walling?
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.
What are the 3 ways of waterproofing a basement under BS 8102?
Under BS 8102 there are three types of basement waterproofing:
- Type A – Barrier Protection
- Type B – Structurally Integrated protection
- Type C - Drained protection
What is basement tanking (Type A)- barrier protection?
- Type A – barrier protection – internal or external waterproof membrane is installed to protect against water ingress
What are Structurally Integral Protection basements (Type B)?
Type B - Structurally integrated protection – requires structure to be constructed as an integral water-resistant shall. For example, by implementing reinforced concrete to an appropriate design code such as BS 8110 or BS 8007
What is a drained cavity basement (Type C)?
Basement waterproofing Type C – Drained Protection – structure incorporates a drained cavity within the basement. Cavity collects groundwater entering through the structure and director it to drains or sump for removal.
What are the risks with building basements?
- 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.
What is build ability?
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.
How is composite metal cladding fixed to a steel frame?
- Bolted
- Riveted
- Welded.
How did preliminaries costs vary with the different facade construction?
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.
What is considered a modern method of construction?
- Panellised units produced in a factory and assembled on-site to produce a three-dimensional structure.
- Volumetric construction to produce three dimensional modular units in controlled factory conditions prior to transport to site.
- Hybrid techniques that combine both panellised and volumetric approaches.
How would you increase waterproofing to concrete?
Waterproofing additive
Waterproof membranes
Explain activities involved when piling?
Measure in line with Section 1 of NRM1
- Forming pile mat
- Mobilisation/moving of pile rig
- Pouring insitu RC piles
- Cutting top of piles
- Pile Caps
- Pile testing
- Pile casings if applicable
How would you increase waterproofing to concrete?
Waterproofing additive
Waterproof membranes
How long does concrete take to cure?
- Set: 24-48 hours`
- Full cure: 28 days
When would you advise to use a piled foundation?
- High rise building
- High load bearing
- Subsoil cannot hold weight of structure
What was the build up to the basement wall?
Secant wall piling, wall cavity, internal block wall, waterproof layer, 2 layers of plasterboard
What are the different options for retaining walls?
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)
What is a diaphragm wall?
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.
Why use secant wall piling and not contiguous?
Secant wall piling generally reduces the chance of water entry into the basement.
What are the different types of heat source?
- CHP plant room (HIU regulates heat into units).
- Boilers
- Air source heat pump
- Ground source heat pumps
What are the types of air conditioning?
- 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.
What materials are used for rainscreen cladding?
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.
What is a screed?
A thin top layer of material (sand and cement) laid on to a floor surface to level it out
What are the types of screed?
- 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.
What are recent changes to building regs?
- 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.
What is a BMS?
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.
What is asbestos?
A fiberous material used for insulation.
What are MMCs?
- MMC is a term used in the construction industry to describe new technologies that improve the requirements of speed, quality and reliability on site. I
- n 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.
What is Grade 1 performance level/ grade basement?
Grade 1 – used in car parks, plant rooms (excluding electrical equipment), workshops - some leaks and damp patches tolerable
What is Grade 2 basement?
Garde 2 – used in workshops and plant rooms requiring drier environment and in retail storage areas – no water penetrations/ leaks tolerable
What is Grade 3 basement?
Grade 3 – used in ventilated residential and working areas including offices, restaurants, leisure centres etc. – dry environment
What is Grade 4 basement?
Grade 4 – used in archives and stores requiring controlled environment – totally dry environment
What are basement grades/ performace levels?
Table 1 of BS 8102:2009 (Code of practice for protection of below ground structures against water from the ground) defines performance levels for the dryness of buildings in four grades, as follows:
- Grade 1 – used in car parks, plant rooms (excluding electrical equipment), workshops - some leaks and damp patches tolerable
- Garde 2 – used in workshops and plant rooms requiring drier environment and in retail storage areas – no water penetrations/ leaks tolerable
- Grade 3 – used in ventilated residential and working areas including offices, restaurants, leisure centres etc. – dry environment
- Grade 4 – used in archives and stores requiring controlled environment – totally dry environment
What informations need to be provided pre-demolition?
- Asbestos demolition survey (to HSG264 standard).
- Utility information (showing disconnection locations if previously carried out).
- Structural hazards and risks (including relevant information such as condition, modifications, materials, etc).
- Hazardous materials and health hazards.
- Building regulations. Where demolition work is proposed, the owner must give the local authority building control department six weeks notice under Section 80 of the Building Act.
- Party Wall etc. Act notices.
- Desk studies indicating the historic use of buildings and land, contamination, mineshafts, wells and so on.
- Constraints to demolition imposed by the client or by the site conditions.
- Site finish required.
- Pre-construction information (CDM regulation 10).
- Planning permissions and potentially Environmental Impact Assessment (EIA)
Please explain the general demolition procedure
- Site and security set-up.
- Intrusive pre-demolition surveys (such as; asbestos survey for demolition, structural survey, hazardous materials surveys, etc).
- Isolation of utilities and removal of meters.
- Disconnection of utilities.
- Asbestos removal (in accordance with the Control of Asbestos Regulations).
- Soft strip (taking the structure back to construction materials including the removal of windows and door frames).
- Superstructure demolition with special measures as constraints demand, such as de-build or protection of adjacent structures.
- Removal of demolition arisings
- Slab and foundation demolition.
- Processing of arisings.
- Site finishes as required.
What methods of demolition are you aware of?
- TOTAL DEMOLITION - The demolition of an entire structure or site.
- SELECTIVE DEMOLITION - Removing specific parts of a building. For example, when a building is listed there may be some restrictions as to what and how much can be demolished.
- INTERIOR DEMOLITION Demolition particular parts of the inside of a building, while protecting and maintaining the exterior structure. For example; partitions, walls, ceilings, etc.
- DISMANTLING OR DECONSTRUCTION - This method involves the careful dismantlement or deconstruction of a building or structure in order to preserve parts for reuse, refurbishment or recycling.
- EXPLOSIVE DEMOLITION - A highly specialised type of demolition, explosive demolition involves using explosives to bring down high reach building structures. This type of demolition work will target the structural support of a building so that it collapses in on itself.
Please explain the process of removing asbestos
- Asbestos survey MUST be carried prior to any asbestos works
- Establish categories of the asbestos
- Licensable asbestos-containing materials – Contractors for removal are held by HSE
- Non-licensable asbestos-containing materials – for example, asbestos cement panels and asbestos toilet cisterns - May be removed by non-license holders but the work must be carried out in accordance with HSE requirements by suitably trained personnel for the work
- 14 days notification period to HSE is required before works can take place.
- Removal of the asbestos must be undertaken under very controlled conditions
- All asbestos-contaminated waste must be despised to an Environment Agency licenced asbestos landfill site, carried by vehicles marked with hazardous waste signage
What are the types of asbestos surveys?
- Management Surveys
- Refurbishment/Demolition survey
What is asbestos management survey?
- The Management Survey purpose is required to manage ACM during the normal occupation and use of premises.
- Survey is undertaken to ensure that nobody is harmed by presence of ACM; that the ACM remain in good conditions and nobody can disturbs it accidentally.
- Survey must locate ACM that could be damaged or disturbed by normal activities.
- can be make by a duty-holder if simple
What is Refurbishment/ demolition survey?
- The Refurbishment / demolition Survey is required where the premises, or part of it, need upgrading, refurbishment or demolition.
- The Survey does not need a record of the ACM condition.
- Normally, a surveyor is needed for Refurbishment / demolition Surveys.This survey is undertaken to ensure that nobody will be harmed by work on ACM and the work will be done by the right contractor in the right way.
- The Survey must locate and identify all ACM. It involves destructive inspection and asbestos disturbance. The area surveyed must be vacated, and certified ‘fit for reoccupation’ after the survey.
Why is asbestos dangers?
- Disturbing asbestos-containing material (ACM) can release invisible fibres. Once in the air, fibres can be breathed in and cause lung diseases
Where can you find asbestos?
- Sprayed coatings on ceilings, walls, beams and columns
- Loose fill insulation
- Toilet seat and cistern
- Asbetos cement roof
- Vinyl floor tiles
What type of asbestos do you know?
- Chrysotile (white asbestos) –usually fine in texture, possessing high flexibility and good heat resistant properties making it ideal for use in cement, lining and roofing materials.
- Amosite (brown asbestos) – mined mostly in Africa, amosite is particularly strong and heat resistant type of asbestos, that was commonly used in cement sheet; has higher cancer risk.
- Crocidolite (blue asbestos) – has very thin fibres
What may influence design of the façade?
- Site, topography and climate.
- The relationship to the street and access routes.
- The requirement for entrances, windows and other openings.
- Stylistic preferences.
- Requirements for climatic modification.
- The need for security and privacy.
- Available skills and materials.
- Regulations.
- Context and planning restrictions.
Factors to consider when constructing a basement?
- The nature of the load requiring support.
- Ground conditions.
- The presence of water.
- Space availability.
- Accessibility.
- Sensitivity to noise and vibration.
- Regulations and planning restrictions
- Type of foundations
What is façade retention?
- Facade retention involves supporting existing façades or party walls for renovation and is often used for works to listed buildings.
- A shoring retention scheme is generally required to support the front façade while construction of the new internal layout takes place. Once construction of the internal structure is complete, the existing façade can be connected to it.
What types of façade retention do you know?
- Scaffolding, suitable for low level facades between 3 and 4 storeys, with sufficient space at their base for installation.
- Proprietary retention, involving props, ties and bracing suitable for higher facades as the general quantity of components are reduced.
- Fabricated steelwork, used when cost of hiring proprietary equipment over long periods of time outweigh the cost of fabricating a structure
- Combinations of fabricated and proprietary retention systems.
What costs need to be consider with façade retention?
- repairs and treatments to the existing façade cost
- façade cleaning cost
- windows and door replacement cost
- scaffolding cost
- temporary works (props, tiles, bracing, fabricated steel works)
- additional surveys -e.g. crack monitoring
Façade maintenance – what is required?
- depends od types of materials, method of construction, condition, required repairs
- the Access report submitted with Stage 4 design included details of how particular part of the building will be accessible (for example access to skylights and external façade through ‘The Street’ by Mobile elevating work platform and mobile tower
Can you please explain principles of deep level basement construction?
Part 1 – Prior to works
- Prior to work – CDM contractor and Principal Design needs to be appointed, Form F10 Notification issued, If ACM present – need to be notify to the HSE,
Part 2 – Demolition may require hoarding if part of the building is to be retained.
- Site and security set-up.
- Intrusive pre-demolition surveys (such as; asbestos survey for demolition, structural survey, hazardous materials surveys, etc).
- Isolation of utilities and removal of meters.
- Disconnection of utilities.
- Asbestos removal (in accordance with the Control of Asbestos Regulations).
- Soft strip (taking the structure back to construction materials including the removal of windows and door frames).
- Superstructure demolition with special measures as constraints demand, such as de-build or protection of adjacent structures.
- Removal of demolition arisings
- Slab and foundation demolition.
- Processing of arisings.
Part 3 – Excavation and Deep Foundations constructions (for example pilling foundation)
- Install pile mat
- secant pile installation
- solid slab raft construction
- basement retaining wall
- basement ground floor slab
- waterproofing (Type A, B or C)
- insulation installation
- wall finishes
What types of deep foundations are you aware of?
- Piles
- Mini piles (or micro piles/micropiles)
- Pile walls
- Diaphragm walls
- Caissons
- Ground anchors
What is diaphragm wall?
- Diaphragm walls are made by excavating a deep trench that is prevented from collapsing by being filled with engineering slurry such as bentonite and then the trench is filled with reinforced concrete panels, the joints between which can be water-tight.
- This is commonly used for top-down construction, where a basement is constructed at the same time as above ground works are carried out.
What are caissons?
- Caissons are watertight retaining structures sunk into the ground by removing material from the bottom, typically this might be suitable for building structures below water level.
What are ground anchors?
Ground anchors transfer very high loads by using a grouted anchor to mechanically transfer load from a tendon to the ground. They can be pre-tensioned or can be tensioned by the applied load.
What modern construction technologies are you aware of?
- 3D pritning
- modular and off side cosntruction
- Drones in surveying
- BIM Modeleing
- Jump Factory East Viilige (Stradford) - new system for constructing high-rise buildings using digital technology and an offsite manufacturing approach, which it has claimed makes construction six times more productive than current industry performance. - one stroy every 55 hours
- cross laminated timber
What benefits can these bring to a project? (Modern methods of construction)
- time saving between 10 to 50%
- more predictble processes and therefore inclreased safety in construction
- more sustainable final product
- better quality
- reduce distruption
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What legislation might be appropriate to consider other than Building regulations on a project.
- Building Act 1984 (Building Act),
- the Building Regulations 2010 (Building Regulations) and
- the Building Regulations 2010 (Approved Inspectors Regulations).
- Construction (Design and Management) Regulations 2015
- Control of Substances Hazardous to Health Regulations (COSHH) 2002
- Health and Safety (Consultation with Employees) Regulations 1996
- Health and Safety at Work etc Act 1974
- Lifting Operations and Lifting Equipment Regulations (LOLER) 1998
- Management of Health and Safety at Work Regulations 1999
- Provision and Use of Work Equipment Regulations (PUWER) 1998
- Work at Height Regulations 2005
- Control of asbestos regulations 2012
- Control of Noise at Work 2005
- HASAWA 1974
What is COSHH?
The Control of Substances Hazardous to Health Regulations 2002 (COSHH) require employers to prevent or reduce workers’ exposure to hazardous substances including:
- Chemicals, and products containing chemicals.
- Fumes, gases, vapours and mists.
- Dusts.
- Nanotechnology
- Biological agents and germs
It does not include lead, asbestos or radioactive substances, which are controlled by other legislation.
