Construction Tech Flashcards
(211 cards)
1
Q
What are the RIBA stages of work?
A
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.
2
Q
what are the 8 stages of RIBA
A
0 - Strategic definition.
1 - Preparation and briefing.
2 - Concept design.
3 - Spatial coordination.
4 - Technical design.
5 - Manufacturing and construction.
6 - Handover.
7 - Use.
3
Q
Strategic Definition
A
the client’s business case and strategic brief are assessed to ensure they have been properly considered’ and the scope of the project is defined.
4
Q
Prep and Briefing
A
developing the information that the design team will need to commence the design process at Stage 2
5
Q
Concept design
A
represents the design team’s initial response to the client’s requirements. Concept design generally takes place after feasibility studies and options appraisals have been carried out and a project brief has been prepared.
6
Q
Spatial Coordination
A
is fundamentally about testing and validating the Architectural Concept, to make sure that the architectural and engineering information prepared at Stage 2
7
Q
technical design
A
The technical design stage (sometimes referred to as ‘design’) develops the design in sufficient detail for co-ordination to be completed and enables packaged, production information to be prepared which can be passed to the contractor and their supply chain to construct the development.
8
Q
Manufacturing and construction.
A
The main contractor will produce working and fabrication information documents at Stage 5 to enable coordination of the full design including manufacturing of off-site materials and components.
9
Q
Handover.
A
The building contractor will hand over documents including a building owner’s manual and the health and safety file. For the design and build teams, Stage 6 can still involve practical tasks, such as discharging planning conditions and rectifying defects.
10
Q
Use.
A
The design team and construction team typically have no duties during Stage 7 of a project, but ongoing feedback is useful for future projects. Post Occupancy Evaluation services help fine-tune a building and inform future projects.
11
Q
How are pad foundations connected to steel columns
A
Through holding down bolts cones and stancion plate
12
Q
How are internal stud partitions formed?
A
- Head and base track
- Stud fixed at 600mm centres (plasterboard typical width 1200mm)
- Insulation between studs
- Pattressing
- Door openings formed
- Abutments, tees, fair ends
- Plasterboard
- Head detail (depends on frame)
13
Q
What does the Building Safety act mean for construction?
A
For the construction industry, it means an overhaul in existing regulations, creating lasting change and makes clear how higher risk buildings should be constructed and managed to ensure that those who use them are safe and feel safe.
14
Q
What updates were there on the 18th edition electrical guidance?
A
It is now a requirement to protect final circuits supplying socket-outlets with a rated current not exceeding 32 A using arc fault detection devices (AFDD) in Higher Risk Residential Buildings, Houses in Multiple Occupation, Purpose-built student accommodation and Care homes
15
Q
What is and Arc Fault detection device?
A
AFDDs are protective devices installed in consumer units to provide protection from arc faults. They use microprocessor technology to analyse the waveform of the electricity being used to detect any unusual signatures which would signify an arc on the circuit
16
Q
What did the tanking detail sign off require?
A
Product spec and details to be signed off by building inspector
17
Q
What did the grouting process in Halifax involve?
A
metre by metre grid dill and grout of shallowing mine workings
18
Q
What are the benefits of raft foundations?
A
The principal aim of a raft foundation is to spread the load of the building across the entire available surface area under the building. This reduces the stress on the ground below, providing a solid foundation that can accommodate ground movement whilst still maintaining structural integrity.
19
Q
What are the disadvantages of raft foundations?
A
In some cases, large amount of reinforcement is required for raft foundation which increases the cost of project.
Special attention on raft foundations is required in case of concentrated loads.
If they are not treated properly, there is a chance of edge erosion.
Skilled workers are required to construct the raft foundations.
20
Q
What are other types of foundations?
A
Strip
Trench fill
Raft
Piling
21
Q
Why did you advise that a raft foundation was required for the modular building?
A
Required as advised by the modular build contractor for drainage and load distribution
22
Q
Why is fire stopping required for certain partitions?
A
Fire rated partitions are required to ensure smoke and fire seal to maintain integrity
23
Q
Why did you advise that partitions could be built to the underside of the ceiling?
A
Fire compartmentation could be maintained and cost saving and programme saving
24
Q
What is MMC?
A
- Modern methods of construction
- Generic term to embrace all processes which reduce level of on-site labour intensity and delivery risk
- UK government has formally defined 7 types - structural (3D boxes, 2D panels, structural components, 3D printing), and non-structural (3D printing, pods & panels & components, smarter materials, better processes)
25
Can you provide some additional benefits of MMC (vs in situ)?
* Quality control
* less waste
* lots of government drive
* better management of embodied carbon
* easier transparency and resourcing in projects
* aid in programme
* safety on site
26
Some of the disadvantages of prefabricated units?
* Requires economies of scale to be worthwhile financially
* Limited funding in private sector
* Lack of trust and knowledge in new technologies
* Lack of control in delivery process
27
QS MMC considerations?
* Costs more, potentially working on different sites, prelims costs
* More suited to milestone payments, vesting certificates, advance payments, materials storage
* Small pool of MMC contractors, lack of benchmarking data available
28
Advise on time/cost/quality of different materials and methods of construction?
- On queenshill project, although higher upfront cost, longer life span and reduced maintenance and repairs costs, reduced programme
pcc planks
roof trusses
29
What to consider for life cycle costing? (LCC)
- Present value, life span, maintenance costs, cleaning and operation costs, discount factor
30
What is meant by life cycle costing?
- Accounting for relevant costs over defined period of time, considering total running costs, maintenance and repair for client to consider in long term use
31
What is meant by whole life costing?
- Broader scope than LCC - can include costs associated with income, externalities, land acquisition (non-construction costs)
32
What is the purpose of life cycle costing?
* Predict cashflow when building is in use
* Carry out options appraisal to decide which is better value long-term
33
What are the different levels of LCC estimates?
According to RICS LCC:
- Component level
- System level (discrete components combined to form a system)
- Element level (construction part performing same function)
- Cluster level (work package)
- Single asset / whole building level
- Multiple assets / portfolio/estate level
34
Can you provide examples of operational processes allowed for in life cycle costing?
[As per life RICS life cycle costing professional guidance]
- IT services
- Cleaning
- Rent
- Insurances
- Energy costs
- Local taxes and charges
35
Can you provide examples of maintenance processes allowed for in life cycle costing?
[As per life RICS life cycle costing professional guidance]
- Redecoration
- Periodic inspections
- Component replacement
- Unscheduled corrective and responsive
- Planned and preventative maintenance and component replacement
36
How do you consider operational and maintenance processes in life cycle costing?
* Consider operational and maintenance processes required
* Consider net present day value of costs
* Calculate annual equivalent value
* Consider how often components will need to be replaced / maintained (will usually state on product specification)
* Input the net present day value at these calculated frequencies over required number of years
37
What data do you use for life cycle costing?
* Sources from historical data - i.e. from facilities managers
* BCIS [life cycle costing]
* Modelling techniques to yield calculations (software)
* Data from manufacturers / suppliers / specialist contractors
38
What are O&M manuals?
* Operation and maintenance manuals
* Contains information required for operation, maintenance, decommissioning and demolition of a building
* Produced by contractor / sub-contractor, with supplementary info from designers (service engineer) and suppliers
39
What might be included in an O&M manual?
* Building’s construction details
* As-built drawings and specifications
* Instructions for operation and maintenance, including H&S info and manufacturers’ instructions
* Asset register of plant and equipment
* Commissioning and testing results
* Guarantees, warranties, certificates
* Requirements for demolition, decommissioning and disposal
40
Typical programme for new build structure?
* Site clearance
* Enabling works
* Site setup (prelims - could be 17-20%)
* Haul & access roads (inc)
* Setting out
* Excavation (machine - could be £5-15/m3 or £40-80/m3 breaking out; hand - could be £15-30/m3 or £50-100/m3 breaking out)
* Foundations (£ as above)
* Frame
* Cladding
* Roof
* Floors
* Services
* Finishes
* FF&E (very much depends on extent that
* Testing and commissioning
* Landscaping
* Snagging
41
Typical programme for existing structure?
* Enabling / facilitating works
* Frame alterations
[- Cladding
* Roof
* Floors]
* Services
* Any RAF
* Finishes
* FF&E
* Testing and commissioning
* Landscaping
* Snagging
42
What is top down construction?
* Allows superstructure and basement to be built simultaneously. GF slab constructed, below ground excavated
* More expensive generally - specialist plant and complex methodology
43
What alternatives are there to top down construction?
Bottom up construction - Traditional method, basement and substructure elements constructed then working upwards. Simpler, but longer programme
44
What is a basement?
Storey below ground storey
45
3 types of basement construction?
* Retaining wall and raft (monolithic) - slab raft foundation, basement walls are retaining walls
* Box and cellular raft - similar to above, internal structure walls transmit and spread loads over raft, divides basement into cells
* Piled - main superstructure loads carried to basement floor by columns, transmitted to ground via pile caps, bearing piles (lots of columns going through basement)
46
3 methods of waterproofing a basement?
* Dense monolithic - designed and built to form watertight space using high quality reinforced concrete, needs strict control and good workmanship
* Tanking (i.e. polythene sheeting, bitumen, epoxy resin), applied internally/externally to provide continuous membrane to base slabs and walls. External better as this protects structure too
* Drained cavity - can be used for new / refurb work. Accepts small water seepage levels, collects and drains away. Inner non-load bearing wall to form cavity, floor laid to falls, moisture drains to sump, discharged direct
-> waterproofing solution often influenced by basement final use
47
Different grades for waterproofing basement?
* Grade 1 - some water seepage and damp is tolerable (i.e. car parks)
* Grade 2 - No water penetration acceptable
* Grade 3 - No dampness / water penetration acceptable (i.e. ventilated resi and commercial areas - homes, offices, shops)
48
Different types of foundation?
* Strip
* Pad
* Raft
* Piled
49
Typical considerations when selecting type and size of foundations?
* Building load
* Nature and bearing capacity of ground
* Structure type
* Cost
* Construction constraints (proximity to nearby structures)
50
Explain the suitability of different foundation solutions
* Strip - well-made ground with good load-bearing capacity, low load-bearing weight from structure
* Raft - poorly made ground with low load bearing capacity- spread load across entire building footprint
* Pad - well-made ground, for structures with high load-bearing points i.e. columns on steel frame
* Piled - High load-bearing, poor ground and tight sight conditions
51
Typical components in ext wall / foundation detail?
Strip foundation
- Concrete block foundation wall
- Rebar reinforcement
- DPC
- Air bricks
- Suspended / GF slab
- Backfilling
- Drainage
52
Why were piled foundations selected for your job at La Plata Grove?
- Poor soil conditions, soil not suitable to prevent excessive settlement. Raft wouldn’t have provided adequate support
53
What are piles?
* Series of columns constructed / inserted into ground to transmit structure load to lower level of subsoil
* Used where no suitable fdn conditions near ground level / high water table, poor bearing capacity of soil
54
Main construction methods for piled foundations?
* Bored piles
* Driven piles
55
Types of piles?
* Replacement - soil excavated to make the pile, relies on end-bearing more than friction (includes flush & percussion bore piles, rotary bored piles, continuous flight auger (CFA) and grout injection piles)
* Displacement - soil pushed aside to insert preformed pile, relies more on friction (includes preformed concrete piles, steel tube piles, partially preformed piles, driven in-situ)
56
Different ways piles transfer load to the surrounding ground?
* End bearing - transfer load through low-bearing capacity soil to strong stratum (rock/dense sand)
* Friction - frictional resistance between outer surface and soil in contact
* Settlement reducing - beneath central part of raft foundation to reduce differential settlement to acceptable level
* Tension (tall chimneys, transmission towers, jetties) - resist uplifting forces that may otherwise cause structure to be extracted from hydrostatic pressure, seismic activity or overturning movement
* Laterally loaded piles - bridge piers, tall chimneys, retaining walls
57
When would you use a bored pile? What’s the process involved?
* Build up areas with cohesive soils (i.e. clay) with requirement to go down 15m+
* Used where load requirement greater than CFA capabilities - larger diameter, greater depths
* Heavy duty crane with Kelly bar, concrete mixer truck and bentonite storage. Soil excavated, bentonite and casing inserted to stabilise, concrete pour with mixing truck and reinforcement cage, casing removed on completion
58
Bored pile vs CFA pile
- Bored piles have excavation and concrete pour done separately, crane + more substantial piling rig, larger diameter and greater depths, casing required
59
Advantages and disadvantages of precast piles?
Advantages
- Can be precast to required spec
- Any size, length and shape can be made in advance
- Driven into granular soil compacts adjacent soil mass -> bearing capacity can increase as a result
- Fast, neat and clean installation
Disadvantages
- Requires heavy equipment to handle and deliver
- Increased noise and vibrations
- Costly if piles are too short
60
Advantages and disadvantages of bored piles?
Advantages
- Any size / shape can be formed on site
- No risk of damage during delivery and handling
- Less vibrations and noise
Disadvantages
- Significant spoils generated - need to be handled
- Reliance and coordination on multiple trades (reinforcement, piling and concrete crews/suppliers
- Don’t improve bearing capacity of ground
61
QS problems regarding cost control with piling?
- End depth never a certainty
62
Cost difference between different types of foundations?
* Varies depending on thickness, material prices
* Piling cost approx £200-£250/m, could be on La Plata Grove cost was around £600-800/sqm (£30k per plot)
* Strip/trench foundations cost £250-£350/m, or £210-250/sqm, £11-13k per plot
* Raft foundations around £200-250/sqm, could have been £10-12k per plot
* I didn’t calculate pad foundations for this particular project but the cost could be £100-150/m3. Need structural engineer’s drawings for cost/m2
63
What is a raft foundation?
* Continuous slab extending over entire footprint of building
* Spread load of superstructure over large base, reduce load per sqm of area
* Useful in load bearing capacity soils and heavy individual column loads
* Solid raft slab / beam and slab raft - ground beam system and suspended PC concrete GF
64
What conditions are required where you’d expect a raft foundation?
* Lightly loaded buildings, poor soils
* Heavy loads can cause raft to move sideways (as it’s not very deep)
65
What is a strip foundation?
* Formation in strip of linear structure, spreading weight across total ground area (supports masonry)
* Suitable for most subsoils and light structural design
* Usually reinforced
66
What are pad foundations?
- Provide a base for reinforced concrete / steel columns. Usually constructed from reinforced concrete, square / rectangular on plan
67
How are foundations constructed?
* Setting out
* Excavation and disposal
* Relevant formwork
* Install rebar
* Concrete pour (/ drive in)
* Cut rebar / connect into slab
* Pour ground slab (after relevant reinforcement installed)
68
How to reduce / control moisture levels in a basement? (and how much would this cost?)
Archives
- Dehumidifier (£20-30/sqm)
- Pollution, temp and humidity sensors (£10-15/sqm)
- Replacing lighting with more energy efficient bulbs (£20-25/sqm)
- Air conditioning system (£30-40/sqm)
- Manual winches to heaters (£500/each)
- Leak detection sensors (£15-25/sqm)
[+ tanking]
69
Typical elemental cost?
£/m2
- Enabling works (£50-150/sqm)
- Substructure (exc basement) - £80-150 (inc basement £250-350)
- Frame and upper floors £300-450
- Roof (£300-£500)
- Stairs (£8-10k per storey)
- External walls (£500-800)
- Internal walls and partitions (£130-£200)
- Internal doors (£450-£2500 each)
- Finishes (£150-£300)
- FF&E (£90-£120)
- Services (£450-650)
70
Different types of internal walls?
* Timber stud (£50-80/m2)
* Metal stud (£80-110/m2)
* Brick partitions, depends on whether single or double skin (£70-150/m2)
* Block partitions (£60-90/m2)
* Concrete partitions (reinforced) £250-£350/m2
* Glazed walls £500-800/m2 - can be much more expensive with acoustic considerations
* Sliding partitions £2k/m, or £600-900/m2
* eo for curved work could increase costs by about 20-30%
* Manifestations £150-200/m2
71
What are the main factors that might affect the choice materials for internal partitions?
* Strength - if fixings required
* Level of transparency required
* Acoustic and fire rating
* Fixed / movable
* Thermal properties
* Door/window requirements
* Height
72
What is plywood?
Plywood = wooden material, made up of several sheets of thin wood. Less durable and easy to work with
73
What is plasterboard?
Plasterboard (aka gypsum) = material sandwiched between 2 thick sheets of paper, modern alternative to plaster (though usually tape and jointed too). Comes in large panels (say 1200m width) and easy to cut
74
Plywood vs plasterboard?
* Plasterboard = cheaper, easier to work with, fix, and install, easier to decorate, can be more fire resistant, better sound dampening properties, more versatile
* Plywood = lighter, stronger, more damage resistant (but more expensive to fix)
75
Why are manifestations required?
* Privacy
* Accessibility (see where windows / doors are) and prevent injuries
76
Manifestation regulation requirements?
* Glass doors and screens clearly defined on 2 levels (850-1000mm and 1400-1600mm above floor)
* Manifestation can take form of logo / sign at least 150mm high or decorative feature at least 50mm high
77
Acoustic benefits and limitations of different internal wall types?
* Stud - Can install insulation and plasterboard but stud itself doesn’t necessarily contribute to soundproofing
* Brick/block partitions - if two walls thick, can have insulation + dense blocks + acoustic plasterboard = very effective solution, but takes more space and more cost. Limited options if only single skin
* Glazed - thin wall, aesthetic, aids function of keeping meeting rooms visible but helping confidentiality of conversation, but may require thicker glass / more absorptive materials -> more expensive
* Sliding / folding walls - they can be made sound proof and aid with the flexibility of the space, however need to be closed fully (no gaps) to minimise sound travelling and is more expensive
78
How to make a wall more soundproof?
* Add high density material (i.e. acoustic plasterboard (higher density core), soundproof barriers)
* Insulation (between stud frames) to absorb sounds
* Curtains
* Acoustic clips - designed so noise that transfers through building structure can’t due to being separated
* Sealing edges of soundproof boarding and wall perimeter
* Acoustic putty
* Double thickness walls (expensive, hard to build, take up more space)
* Acoustic batts (reduce and absorb sound, cotton / fibreglass)
[- Expanded foam sprays are more for thermal insulation]
79
Partition build up?
* Head and base track
* Stud fixed at 600mm centres (plasterboard typical width 1200mm)
* Insulation between studs
* Pattressing
* Door openings formed
* Abutments, tees, fair ends
* Plasterboard
* Head detail (depends on frame)
80
How do you construct a glass partition?
* Glass fixed into frame (wood / steel)
* Glass placed in a rebate, secured with putty / beading
* Frame mounted between walls / columns required, usually secured with putty
81
Different types of balconies?
* Bolt-on - cantilevered off building or on open mesh deck, bolted onto building exterior with support system, say £7-12k each
* Juliet - full height glazing with railing, but no outdoor space, say £2-3k each
* Inset - constructed with the frame and structure- recessed into the facade of a roof / building, say £5-10k each
[- Roof terrace (minimises usable GIA - premium feature), cost depends on spec, build up can include waterproofing, decking structure, finish, access for services]
82
How to construct inset balconies?
.e. on DBE
- Build as continuation of slab and construct walls around it
- Waterproof membrane
- Thermal break
- Slab decking system (on adjustable pedestals)
- Concrete banding
- Fairfaced concrete finish (can be tiling, paving slabs)
83
Inset vs bolt on balcony?
* Inset generally cheaper (less balustrading, decorative details
* Bolt on can save on time
84
Factors affecting balcony choice?
* Cost
* Complexity of installation
* Location
* Size and design
85
How do stacked services have impacts on costs?
- When stacked, there’s shorter and simpler distance to travel - less cabling, easier buildability
86
What site surveys might be required for typical construction project?
* Topographic survey
* Site investigation
* Asbestos survey
* Drainage CCTV
* Utility searches
* Ecological
* Flood risk assessment
* Transport assessments
* UXO discovery
* CBR test
* Archaeological dig / excavation
* Existing condition survey
* Geotechnical survey
* Structural survey
* Condition survey (similar to struct, more on building fabric-materials)
87
Main site considerations?
* Access
* Storage and accommodation
* Temp services
* Plant
* Hoarding / fencing
* H&S
- security
88
Main site considerations?
* Access
* Storage and accommodation
* Temp services
* Plant
* Hoarding / fencing
* H&S
- security
89
What are the objectives of a site investigation?
* Primary purpose to establish parameters for foundation and substructure design
* Assess properties and composition of soil and rock, potential ground contamination
90
Typical components of site investigations?
* Systematically collect and record data to help design / construction
* Adjacent site impacts
* Boundary hedges / fencing
* Existing trees, buildings
* Services location (gas, phone, elec, water, drainage)
* Ground water conditions
* Soil investigations
91
What surveys were undertaken on your project to inform foundation choice?
- i.e. Geotechnical technical survey and soil investigation
92
What are temporary works?
- Part of construction works not usually on drawings but are needed to enable permanent works to be built safely
- propping, scaffolding, formwork, excavation support
93
What is formwork?
- Anything holding fresh in situ concrete in place until it hardens - plywood shutters, profiled decking, steel plan forms, fibreglass moulds
+ accessories i.e. wedges and clips for tightening joints and to make stripping easy
94
Main types of excavation?
* Open - battered excavation sides cut back to safe angle, eliminates need for temp support work, easily construct basement walls BUT extra excavation costs, needs a lot of space
* Perimeter trench - trench dug to form basement walls, supported as required. Basement walls constructed then inside excavated
* Complete excavation - firm subsoils, centre of basement excavated first, then basement slab cast while sides of excavation supported by struts
95
Different forms of excavation?
* Site clearance (remove vegetation and rubble)
* Strip topsoil
* Reduced level dig (reach formation level)
* Cut and fill
* Excavation for foundations
96
Key factors to consider when excavating?
* Soil type, moisture content
* Method
* Whether ground support systems required
* Proximity of existing buildings
* Depth required
* Underground services and drainage
97
What is underpinning? Why might it be required?
* Method to repair and strengthen foundations
* Stabilises fdns undergoing settlement/movement/erosion/vibration damage
* Increase load capacity of existing fdn
* Accommodate new adjoining building, basement or deep sewer
98
Techniques available for ground improvement?
* Vibro compaction
* Vibro stone columns
* Vertical drains and vacuum consolidation
* Soil mixing
* Dynamic compaction
* Dynamic replacement
99
What is ground heave?
* Associated with clay soil (swells when wet), causes ground to move upwards
* Soil can’t expand downwards / sideways -> exposed upper surface rises up
100
What is the external envelope?
* Materials and components forming external shell / enclosure of a building - boundary between interior and exterior
* May be load or non-load bearing
* Typically consists of brickwork, cladding, curtain walls
101
Key considerations designing external walls?
* Weather protection
* Fire resistance
* Acoustic, thermal and structural performance
* Aesthetic / appearance
* Lifespan
* Future maintenance
102
Different cladding materials?
- Timber, aluminium, brick, slip, PCC, glazed, stone
103
What is a movement joint? Why are they used?
* Safely absorb expansion and contraction of construction materials
* Allow for movement associated with ground settlement, seismic activity
104
In brick/block cavity wall, how are window openings dealt with?
- Prevent water penetration - cavity tray (DPC crossing cavity, forming gutter leading to weephole in outer leaf) and DPC (same width as wall to stop moisture rising from the ground up external leaf of wall
- Structurally - Lintel, small beam over window / door head usually carries wall load only
105
Stick vs unitised cladding system
* Stick - constructed onsite, transoms and mullions (vert and horiz respectively) made from aluminium, connected together on-site to floor slabs
* Unitised - Component parts constructed off-site - pre-fab units delivered to site and fixed straight to building
106
Benefits and limitations of stick vs unitised system?
Stick
- Lower cost, flexibility due to on site construction
- Longer to erect on site, requires more labour, less quality control
Unitised
- Erected on-site in 1/3 of time, better quality control, achieve more complex design
- Higher cost, risk of mistakes during fabrication affect installation on site
107
Types of curtain walling?
* Stick - panels / glazing in between transoms
* Unitised - narrow storey height units, preassembled in factory
* Panelised - large preassembled panels connecting back to structural columns
* Structural glazing
108
Frame materials?
* Steel
* Concrete
* Timber
* Hybrid (i.e. CLT)
* Load bearing masonry
109
Key factors to consider when selecting structural frame type?
* Programme
* Fire protection
* Acoustic and thermal properties
* Market conditions, supply costs
* Site constraints/logistics
* End user requirements (i.e. column free space)
* Sustainability objectives
* M&E strategy
* Future expansion requirements
110
Components of steel frame construction?
* Beams, columns
* Purlins
* Rafters
* Eaves, eaves haunch
* Base plate
* Apex haunch
* Cladding rails
* Fixings
111
Steel frame advantages and disadvantages
ADV
- 100% recyclable, won’t warp, crack, split, nor be vulnerable to termites / organisms
- Highest strength:weight ratio
- Dimensionally stable - won’t expand / contract depending on weather conditions
- Consistent material quality, strictly produced in accordance with national standards, no regional variations
- Non-combustible- won’t contribute to spread of fire
- Lighter- in poor soil conditions steel is preferred to concrete
- Faster to install than concrete
- Can span over long distances
- Manufactured on-site - quality benefits
- Voids within floor can run services
- Suitable for irregular shaped buildings
DISADV
- May need fire protection
- Although they don’t burn, they fail (collapse) before wood component in fire
- Parts may need replacing
- Variable cost
- Experienced builders required (+ cost)
- Lower load bearing capacity vs concrete
- Don’t have same acoustic / thermal properties of concrete frame
- Prone to corrosion in coastal areas
- High embodied carbon (often procured from abroad)
- Long lead-in times - Letter of intent / materials off site may be required
112
Different parts of steel beam?
- Flange - top and bottom of vertical steel
- Web - vertical steel part of I
- Root - where flange and web join
113
Weight of steel?
- 10mm3 = 0.0078kg
114
What is intumescent paint?
* Fire-resistant paint, passive fire protection system
* Rapidly expands in extreme temps to protect surface it’s applied to
* Prevents/minimises/delays structural fire damage
115
Steel connections and percentage?
- Plates, bolts, welding.
- 5% by weight
116
Concrete frame advantages and disadvantages?
:)
- Concrete framed buildings marginally less than steel framed buildings
- Fire protection is part of structure
- Slower - reduces cashflow early on
- Low maintenance
- Cladding easily fixed to concrete and replaced
- Good sound and heat insulation
- Insitu allows alteration at late stage of construction
- Complex geometrical shapes easier dealth with than steel
- High compressive strength
- Lower embodied carbon - can be made with by-product of coal and iron industry
:(
- Slower to construct, inc long curing time
- Requires formwork
- Edges may not be as square / surfaces not as flat as steel
- Steel reinforcement leads to cost issues associated with steel
- Heavier -> larger foundations
- Bulkier structure
- Doesn’t span as well as steel
- Low tensile strength
- Higher floor height required to accommodate services
- In-situ quality dependant on skill of operatives
117
Elements of a pitched roof?
* Rafters, battens, eaves, fascia, soffit, gutter, joist, ridge, ridge board, hanger, membrane, tiles
* Vent tiles may be used to provide natural ventilation to roof space
118
Main components of hipped end timber roof structure?
* Principle rafters (support to roof covering, eaves to ridge)
* Jack rafters (shorter rafters, hip to eaves / ridge to valley)
* Ridge board (spine of roof carcass along ridge)
* Wall plates (receive feet of rafters at top of external wall)
* Hip rafters (where 2 roof surfaces meet, form ext angle)
* Valley rafter (where 2 roof surfaces meet to form internal angle)
* Bargeboards / fascia (to cover feet of rafters)
* Purlins (intermediate horizontal members supporting rafters)
* Battens (small pieces of wood which roof covering is affixed)
119
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
120
Different types of flat roof coverings?
* Single layer membrane - one layer of felt consisting of base sheet of glass fibre/polyester, impregnated with hot bitumen during manufacture
* Cheapest option, but too thin, easily punctured and rarely used
* Built up membrane - 3 layers of above felt, 1st laid at right angles to fall, next is perpendicular, and again for third layer. Covered with stone chippings
* More durable than above, but can be easily punctured without proper care
* Asphalt - Aggregate with bituminous binder cast into block. Reheated onsite at 200deg, transported as liquid to roof. Usually 2 coats
* Reduced risks of defects (poured on site, not in rolls which may be damaged in transport), hard wearing, can allow transit on top, can have long life guarantee
* Hot temperature - apt H&S measures required
121
Describe typical cold flat roof construction
* Insulation above ceiling level - between roof joists and below roof deck
* Risk of condensation forming within roof void / on underside of slab - good cross ventilation essential
* Plywood decking secured to joists and finished with roof covering
122
Describe a typical warm flat roof construction
* Insulation on top of roof deck, beneath waterproof membrane
* Vapour control layer under insulation
* Reduces risk of condensation as ceiling / roof void at similar temp
123
Describe a typical inverted flat roof construction
* Insulation on top of waterproof membrane - anchored down, protects membrane from damage
* No vapour control required
* Roof void and deck maintained at similar temp to room
124
Cold vs warm flat roof?
* Insulation position varies
* Warm - between roof rafters, above roof level
* Cold - between rafters and service voids
125
Green vs blue roof?
* Green - absorbs rainwater, habitats wildlife, aesthetics, helps lower urban air
* Blue - collects water and releases slowly after rain’s stopped, e.g. attenuation tank
[both are forms of SUDS]
126
What would you expect to find on timber / part glazed door with FR30 requirement?
* 3 hinges
* Intumescent strip
* Self-closing device
* Part glazed door - 6mm thick, wired to max 1.2sqm with 13x13mm wood beads encased with non-combustible materials
127
Types of ventilation?
- Natural - Method of supplying fresh air to building / room via passive forces, i.e. wind speed, pressure - Reduced carbon emissions key benefit
- Mechanical - Intentional fan driven flow of outdoor air into building
- Can include supply and/or exhaust fans
128
What is an air source heat pump? How does it work?
* Takes heat from air, boosts it to a higher temp using compressor
* Transfers heat back to heating system
* (like the reverse of a fridge / air conditioner)
* Can also have a split ASHP - system put in reverse to provide cooling
129
What is a VRF? / What can be used to provide cooling in localised part of building?
* Variable refrigerant flow (AC system)
* Controls refrigerant flow to each FCU
* Heat pump system - can provide simultaneous heat and cooling
* Heat pump connected to indoor units
* Energy recovered from 1 zone can be used to heat separate zone
* Less space than traditional ductwork, more efficient compared to other systems
130
Why do we stall generators in addition to regular grid power?
* Powered by diesel engines - backup power supply if primary one fails
* Generators becoming less common as technical advances being made in UPS
131
How is power distributed to floor boxes in raised floor?
* Incoming power supply connects to low voltage switchboard, connects to a distribution board
* Dist board has underfloor busbar connected - busbar has sockets which floor box plugs are put into via flexible lead
* Floor box has sockets to which appliances can plug costs
132
Different types of lift?
* Passenger - specialised for service they perform (i.e. hospitals with front/rear entrances)
* Residential - Small enough for 1 person, some can be for 12+
* Platform - Wheelchair/platform lifts- specialist, designed to move wheelchair <2m. Accommodate 1 person, max load 340kg
* Freight - Similar to passenger lifts, but designed to carry goods (though there’ll still be passengers so building regs still apply). Larger, capable of carrying heavier loads - 2300-4500kg. Manually operated doors, hydraulic freight / electric options (latter is more energy efficient)
* Dumbwaiter - Small freight elevator often for moving small items (i.e. in 2-storey kitchen). Small electric motor with counterweight or can be hand operated, capacity about 340kg.
133
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
134
What is a utility easement?
- Legal agreement giving utility company access to use property for the good of a community
135
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
136
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
137
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
138
How to form a highway?
* Break out existing
* Excavating
* Capping
* Sub-base (100-250mm)
* Base (70-150mm)
* Binder (50-100mm)
* Surface/wearing course (20-40mm)
* Road restraint systems
139
Flexible vs rigid paving?
* Flexible - subbase, base, binder, surface course. Initial cost lower, less curing time, lower repair costs. Less durable, higher maintenance costs.
* Rigid - subbase, concrete slab (less thick). More durable, low maintenance costs, no good subgrade required. High initial and repair cost
140
Have you come across the term SUDS?
* Sustainable Urban Drainage System
* Manage stormwater locally (close to source as possible) to mimic natural drainage, encourage infiltration and/or attenuation
* Help reduce reliance on existing drainage infrastructure
141
What are Building Regulations?
* Min performance standards for design and construction of buildings, supported by Approved Docs and other codes of practice
* Regulations ensuring new buildings, conversions, renovations, extensions will be safe, healthy and high-performing
* Cover specific topics, inc structural integrity, fire protection, accessibility, energy performance, acoustic performance
142
Why do we have building regulations?
* Establishes min stds and guidance on construction elements
* H&S
* Enables mortgages and insurances to be granted
143
What type of building work is covered by Building regulations?
* Erection / extension of building
* Extension of service controlled by regulations
* Alteration projects with temp/permanent effect on building - structure, fire and access
* Insertion of insulation into cavity walls
* Underpinning building foundations
144
Process for building control sign off?
* Building notice submitted to local planning authority - small projects
* Full application (drgs and spec submitted) - BCO visits site and inspects works, larger new build projects
* Local authority / approved inspectors will come to sign off
145
Alternatives to building control officer?
- Approved inspector
146
What are British Standards?
* Publications issued by British Standards Institution, prefixed BS
* Give min standards for materials, components, design and construction practices
147
What are international standards?
* Prepared by International Organisation for Standardisation, prefixed ISO
* Compatible with and complement BS’ (i.e. ISO 9000 is quality)
148
What are the Building Regulations approved documents?
* General guidance on performance of materials, to comply with functional requirements of building regulations - practical examples
* Only guidance, no obligation to adopt specific solutions if requirements can be met via alternative means
Part:
- A - Structure
- B - Fire Safety
- C - Site preparation
- D - Toxic substances
- E - Sound resistance
- F - Ventilation
- G - Sanitation, hot water safety and water efficiency
- H - Drainage and waste disposal
- J - Combustion appliances and fuel storage system
- K - Protection from falling, collision and impact, opening and cleaning
- L - Conservation of fuel and power
- M - Access to and use of buildings
- N - Glazing - safety in relation to impact, opening and cleaning
- P - Electrical safety
- Q - Security - dwellings
- R - Physical infrastructure for high-speed electronic communication networks
- S - Infrastructure for charging electric vehicles
* Regulation 7 - Materials and workmanship
149
Changes to building regulations?
Part B Fire safety
- Hotels 18m+ included in definition of relevant buildings (must have above certain cladding grade)
- Cavity trays required in relevant buildings (other than those with masonry non-combustible external walls)
- Aluminium composite panels (ACM) banned from use on all buildings
- Evacuation Alert System for 18m+
- Secure information boxes for Fire and Rescue service for flats 11m+
- Sprinkler systems 11m+
- Emergency wayfinding signage 18m+
- Firefighting shaft in basements (2nr required in buildings over 900m2)
150
New building regulations in effect this year?
From 15th June 2023
- Reduction of carbon emissions (~ 30%)
- New metric for energy efficiency - “primary energy” to measure building heating efficiency
- New minimum efficiency standards
- Heating and lighting efficiency - particularly for existing
- EV charging points (preparatory work for future installation) to all new domestic builds
- Avoid overheating - New approved document O to introduce glazing limits to reduce unwanted solar heat
- Limitation periods extended from 6 to up to 30 years for dwellings
151
New legislation regarding building safety?
* Fire Safety (England) Regulations 2022
* Building Safety Act 2022
* Fire Safety Act 2021
152
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
153
Purpose of the Fire Safety (England) Regulations 2022?
Effective January 2023
- Following Grenfell Tower inquiry recommendations
- Fire fighting service found it difficult to navigate buildings
- Responsible persons of high-rise residential buildings to provide info to local fire and rescue service
- High rise resi building = 2+ domestic premises and 18+m tall / 7+ storeys
154
Duties of the Responsible Person under the Fire Safety Act?
* General: display fire safety instructions and info to residents
* 11+m: fire door checks at least every 3 months, flat door entrance checks at least every 12 months, keep records on external wall construction
* 18+m: wayfinding signage, secure information box for fire and rescue service at readily accessible location
* Keep up to date floor and building plans, shared to local fire and rescue service
* Check lifts, inlets/outlets, sprinkler systems, fire alarm systems, evacuation alert systems
155
Purpose of the Building Safety Act 2022?
* Provides new framework for design, construction and occupation of ‘higher risk’ buildings (18+m / 7 + storeys and 2+ domestic premises)
156
Key provisions of the Building Safety Act 2022?
* 6 parts, contains provisions to secure safety of people in or about buildings
* HSE is the new Building Safety Regulator to oversee safety and standards of buildings, lead implementation of new regulatory framework and encourage built environment to improve competence
* Golden thread of information - digital and accessible audit-trail throughout building life
* New duty holder: “Accountable Person”, must register building with BSR and regularly log info about building and review risk assessments following Completion Certificate
* Mandatory for Building Regulation Approval for projects before commencement (12 weeks from submission of application)
* Amends Building Act 1984 (amends general duties, industry competence, breaches inc offence of contravening regs, regulation of building control profession) and H&S at Work Act 1974
157
Key provisions of the Fire Safety Act 2021?
* Amends Regulatory Reform (Fire Safety) Order 2005
* Increasing and clarifying obligations for responsible persons for multi-occupied residential buildings
* RPs must do fire risk assessment - manage and reduce risk of fire for structure and external walls of building (inc cladding, balconies, windows, entrance doors)
* Allows Fire and Rescue service to enforce against non-compliance
* Regular inspections / review of lifts, evacuation plans
158
Name some materials banned from use in construction?
* High alumina cement in structural elements
* Asbestos
* Urea formaldehyde
159
What safety provisions would you expect to find in an office block?
* Max. occupancy listings
* Fire exits - signage above that function in power failure
* Fire extinguishers and alarms easily accessible
* Restricted use of flammable materials
* Fire alarm control panels - quick detection and warning of fire
160
Different types of planning applications?
* Full (whole detail)
* Householder extension
* Outline (masterplan)
* Reserved matters (RMA)
Everything must be discharged within time frame. Restrictions on times
161
BCO vs approved inspectors
BCO = straight from the local authorities
Approved inspectors = bodies designated by local authorities
162
Size of a brick?
Standard - 215 x 102.5 x 65mm
163
How many bricks per sqm?
60
164
How many UK std size blocks per sqm?
10
165
UK Standard block size
440mm x 215mm x 100mm
166
Different types of brick bond?
* Stretcher - most common half brick thick, vertical joints staggered each time by half a brick
* English - alternating courses of headers and stretchers
167
Brick vs block wall
* Blocks made of concrete / aggregate - bigger, lightweight, higher water resistance, fire resistance
* Brick made of sand, lime and concrete - longer life, can be more aesthetic, often more expensive, low maintenance
168
Common types of plasterboard?
* Standard (white/light grey)
* Fire boards (pink)
* Acoustic (blue)
* Moisture resistant (green)
169
Name some deleterious materials
* Lead (flashings on roofs - waterproofing)
* Asbestos (insulation)
* Brick slip systems
* Woodwool slabs (ceilings)
* High alumina cement (used a lot in 60s, 70s)
* Sea dredged aggregates (high chloride content)
170
Different types of asbestos?
* Chrysolite (white) most common least dangerous
* Amosite (brown)
* Crocidolite (blue)
171
Where have you considered maintenance and operational costs during design stages
* High spec LED luminaires
* Maintenance- central heating plant instead of boilers has benefits of energy use and maintenance
* Maintenance - ASHP uses less energy and ducting
* Cleaning - roof access, cleaning facade methodology
172
What fire safety provisions are there in new buildings?
* Max occupancy numbers
* Fire evacuation plan, escape routes, signage, fire exits
* Extinguishers, alarms
* Sprinklers
* Fire dampers in ventilation ductwork
* Fire barriers - floor, wall and ceiling cavities
* Fire rated roller shutters
* Smoke control systems
173
Fire compartmentation? (in a building)
- Passive fire protection- subdivides structure into fire compartments to limit spread of fire and smoke
174
How are fire barriers formed in suspended ceilings?
* Req in ceiling void if suspended ceiling not fire resistant
* Installed between soffit of floor above and suspended ceiling - ceiling void compartmented
* Need to consider if smoke stops are also required
175
What happens when services pass through fire barriers?
- Need to be sealed to prevent fire spreading through service gap
176
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
177
What impact do new building regulations have on fire safety?
* Buildings over 11m now need sprinklers
* Buildings over 18m need 2 cores
178
What impact will future building regs likely have
* Prohibit combustible materials in external facade, i.e. timber decking and glass on balconies, insulation used
* Maybe high fire ratings required around ext facade
179
Design concerns for fire safety in tall buildings?
* Sprinklers (11m+)
* Dry riser
* Wet riser 50m+
* Fire fighting lifts
* No combustible materials in ext facade
* Fire walling in ceiling voids
* Dampers
180
What systems can be introduced to a building to make it more sustainable?
* Biomass boilers
* Solar panels
* ASHP / GSHP
* LED lighting
* Insulation
* Onsite batteries for PV
* Car charging points
* BMS
181
Benefits / drawbacks of PV panels?
Advantages
- Can generate more than home use to sell energy back to grid
- Renewable energy source
- Reduced electricity bills
- Low maintenance costs
Disadvantages
- Cost
- Weather dependent
- Solar energy storage can be expensive
- Uses a lot of space
- Puncturing roof structure removes roof warranty
182
Legislation for clean air in cities?
UK clean air model 1997 - clean up city air by 2010 (still way behind)
183
Which product is more sustainable timber vs concrete?
* Depends on project- location, material source
* Generally timber, assuming from forestry steward council source
184
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
185
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
186
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
187
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
188
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
189
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
190
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
191
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
192
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
193
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
194
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
195
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
196
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
197
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
198
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
199
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
200
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
201
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
202
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
203
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
204
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
205
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
206
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
207
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
208
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
209
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
210
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
211
Elements of a flat roof?
* Joists (fixed to wall plates- main support)
* Furrings (fixed to joists to give required incline)
* Particle board (fixed to furrings to give flat surface)
* Felt (3 layers bonded with bitumen to give waterproof covering)
* Stone chipping (gives protection to felt, reflects sunlight)
