CONSTRUCTION TECHNOLOGY & ENVIRONMENTAL SERVICES Flashcards
1
Q
What is substructure?
A
- All elements of work that are undertaken below the damp proof course that provides the basis for the
superstructure to be constructed upon.
2
Q
What is the external envelope?
A
- The materials and components that form the external shell or enclosure of a building.
- These may be load or non-load bearing.
3
Q
What are the Building Regulations?
A
- Statutory instruments that set out the minimum performance standards for the design and construction
of buildings. - Supported by the Approved Documents and other codes of practice.
4
Q
What are the approved documents?
A
A. Structure.
B. Fire safety.
C. Site preparation and damp proofing.
D. Toxic substances.
E. Sound proofing.
F. Ventilation.
G. Hygiene.
H. Drainage and waste disposal.
I. Not in use.
J. Heating appliances.
K. Protection from falling, collision and impact.
L. Conservation of fuel and power.
M. Disabled access and facilities.
5
Q
What are British Standards?
A
- Publications issued by the British Standards Institution prefixed BS.
- They give recommended minimum standards for materials, components, design and construction
practices.
6
Q
What are international standards?
A
- Publications issued by the International Organisation for Standardisation – prefixed ISO.
- They are compatible with and complement the British Standards.
7
Q
What is superstructure?
A
- All internal and external works items above the damp proof course.
- This is made up of:
o External walls.
o Stairs.
o Roof.
o Structural walls.
o Suspended ceilings.
o Raised floors.
8
Q
What are the typical components of site investigations?
A
- Their objective is to collect and record data to help with the design and construction process. This
should include matters in relation to the site that may impact the development for example:-
o Boundary hedges & fencing.
o Existing trees.
o Size, depth and location of services including gas, telephone, electricity, water & drains.
o Existing buildings.
o Ground water conditions.
o Soil investigations.
o Trial pit information.
9
Q
What is the purpose of soil investigations?
A
- Their purpose is to determine the suitability of the site for the proposed works and determine adequate
and economic foundation design. - The investigation should determine the potential difficulties associated with the ground conditions and
assist with identifying a suitable foundation solution.
10
Q
What are the main site considerations?
A
- Access considerations.
- Storage considerations.
- Accommodation.
- Temporary services.
- Plant.
- Fencing & hoarding.
- Health & Safety risks.
11
Q
What is a retained façade?
A
- The facade of the building is retained whilst everything behind the front wall is demolished.
- Allowances needs to be made for a temporary support structure and also cleaning & restoration works
to the retained façade. - Retained facades are often required as a result of listed building requirements.
12
Q
What are temporary works?
A
- Temporary works do not normally appear on construction drawings but may be required depending on
the construction methodology being used. - Temporary works may also be required as a result of health and safety requirements to ensure a safe
method of construction for example temporary propping.
13
Q
What is a tower crane and what are some considerations during its
erection and operation?
A
- A tower crane is a tall crane used for lifting objects into high places.
- The boom allows a longer reach with 360° access.
- A longer boom reduces the payload capability.
- You would usually use a smaller crane to erect a tower crane.
- Weather conditions could prevent it from working, in particular high, strong winds.
14
Q
What is a scaffold?
A
- Scaffold is a temporary working platform erected around the perimeter of a building or structure to
provide a safe working place at a convenient height. - Scaffold is usually required for work 1.5m above ground level.
15
Q
Scaffold inspection
A
It is the scaffold users/hirers responsibility to ensure that all scaffolding has been inspected as follows:
-Following installation/before first use
-At an interval of no more than every 7 days thereafter
-Following any circumstances liable to jeopardise the safety of the installation eg high winds
16
Q
Do you have to use Scafftags?
A
Tagging a scaffold as safe to use is best practice although it is not a legal requirement. The opposite is not true if a scaffold is incomplete or unsafe as here you must tag the structure as unsafe in accordance with the Health and Safety Regulations 1996. As well as signage it is also necessary to physically prevent access.
17
Q
What information to be included in an inspection report:
A
Information to be included in an inspection report:
The name and address of the person for whom the inspection was carried out
The location of the inspection
A description of the scaffold
The date and time of the inspection
Details of any matter identified that could give rise to a risk to the health or safety of any person
Details of any action taken as a result of any matter identified
Details of any further action considered necessary
The name and position of the person making the report
18
Q
What is shoring?
A
- Shoring is a form of temporary support given to existing buildings.
- Its purpose is to provide a precaution against damage or injury due to collapse of the structure.
19
Q
What are the main components of concrete?
A
- Cement.
- Aggregate (natural rock, crushed stone, gravel).
- Water.
20
Q
What is a borehole?
A
- A borehole can be used for soil investigation or for geothermal heating solutions.
- Boreholes are the most suitable method of soil investigation when foundations are over 3m deep.
- Geothermal boreholes are permanent boreholes that use the Earth’s natural heat to raise the
temperature of circulated water. - This is a closed system and can be used to heat the building above which is adopted as a sustainable
technology.
21
Q
What are piles?
A
- A series of columns constructed or inserted into the ground to transmit the load of a structure to a
lower level of subsoil. - They are used where no suitable foundations conditions are present near ground level or if there is a
high water table.
22
Q
What are the different types of piles?
A
- Sheet piles.
o A deep trench is excavated and concrete is poured in situ.
o The piles can be used to form basement walls or act as retaining walls. - Secant piles.
o Interlocking piles (male and female, often different diameters and hardness) are bored to
provide a combination of foundations and basement walls.
o They support in providing a waterproof structure and are often seen when a top down
construction method is used. - Bored Piles.
o An auger is used to excavate the soil and then concrete is poured in once complete. - Pre-cast piles.
o Piles are and hammered into the ground. This is not often favoured due to the high noise levels associated with installation and the lack of flexibility in terms of depth required.
23
Q
What are the different ways that the piles transfer their load to the
surrounding ground?
A
- End bearing piles - transfer load through low bearing capacity soil to a strong stratum such as
rock or very dense sand. - Friction piles - bear on frictional resistance between their outer surface and the soil in contact.
- Settlement reducing piles - usually incorporated beneath the central part of a raft foundation in order to
reduce differential settlement to an acceptable level. - Tension piles - resist uplifting forces that might otherwise cause the structure to be extracted
from the ground due to uplifting forces such as hydrostatic pressure, seismic activity or
overturning movement.
24
Q
What is the difference between bored vs. pre-cast piles?
A
- Bored piles are defined when the process for removing the spoil to form the hole for the pile is carried
out by a boring technique. - They are used primarily in cohesive subsoils for the formation of friction piles and when forming pile
foundations close to existing buildings where the allowable amount of noise and/or vibration is limited. - Pre-cast Concrete piles are generally used where soft soil deposits overlie firmer strata. These piles are
usually driven using a drop or single action hammer. - Issues can arise due to the noise levels associated with the installation method of pre-cast piles.
25
What are the problems to the PQS regarding cost control with piling
and who owns the risk?
* The end depth of the piles are never certain and the procurement route used determines who takes the
risk.
* For example under a traditional or design & build procurement the main contractor would normally
take risk ownership whereas under management contracting the risk would remain with the employer.
26
What is a raft foundation?
* Raft foundations spread the load of the superstructure over a large base and reduce the load per m2 of
the area.
* Raft foundation solutions are useful in low bearing capacity soils.
* They can be a solid raft slab or beam and slab raft such as a ground beam system and suspended PC
concrete ground floor.
27
Under what conditions would you expect a raft foundation to be used
for a substructure?
* A raft can be used for lightly loaded buildings on sites with poor soils.
* Heavy loads to the raft have the potential to cause the raft to move sideways as a result of raft
foundations not being very deep.
28
What is a strip foundation?
* Strip foundations are formed by creating a shallow continuous excavation to support the
perimeter and internal walls.
* They are also referred to as strip footings and are suitable for most subsoils and a light
structural design.
29
What are pad foundations?
* Pad foundations provide a base for reinforced concrete or steel columns.
* They are usually formed by making an isolated excavation in the shape of a square or rectangle.
* They often have reinforcement mesh as part of the construction and spread the load to a layer of
bearing soil or rock below.
30
What are retaining walls?
* They act as an earth retaining structure for the whole or part of their heights.
* They are used to support and retain soils laterally so that it can be retained at different levels on the two
sides.
31
What are the main types of excavation for forming basements?
Open excavations that use battered excavation sides which are cut back to a safe angle. This eliminates
the need for temporary earth work support and can be used to construct basement walls. This requires
additional excavation costs and significant working space when compared to other methods.
* Perimeter Trench Excavation can be used to form basement walls. This method requires earthwork
support with the basement walls being constructed and then the inside of the basement is excavated.
* Complete Excavation can be used in firm subsoils. The Centre of the basement is excavated first, then
the basement slab cast while the sides of the excavation are supported by struts.
32
What are the 3 different types of basement construction?
* Retaining wall and raft which consists of a slab raft foundation to serve as the basement floor that
distributes the building load. The basement walls serve as the retaining walls.
* Box and Cellular raft which is similar to above however the internal structural walls are used to transmit
and spread loads over the raft and divides the basement into cells.
* Piled solution where the main superstructure loads are carried to the basement floor by columns and
transmitted to the ground via pile caps and bearing piles. In this example the basement has numerous
columns passing through it.
33
What are the 3 main methods of waterproofing a basement?
* Dense monolithic where the basement is designed and built to form a watertight space using high
quality reinforced concrete. This requires good workmanship and strict control. Success depends on
the water to cement ratio and the degree of compaction. Joints also need to be carefully designed
* Tanking using materials such as asphalt, polythene sheeting, bitumen and epoxy resins. These can be
applied internally or externally to provide a continuous membrane to the base slabs and walls. External
application is better as it protects the structure in addition to the waterproofing.
* Drained Cavity solutions can be used for new or refurbishment work. This allows a small amount of
water infiltration to occur. The water is collected and then drains away to a sump or is directly
discharged using a pump.
34
What is scabbling?
* Scabbling utilises piston driven carbide tipped heads which impact the surface material at a rapid rate.
* This pulverises concrete or brittle coatings and can be very effective in the removal of slightly bonded
coatings or where the coatings are impossible to be removed by the shot blasting process.
* It can also remove level inconsistencies in concrete floors.
35
What are the technical advantages of steel frames?
* Steel frames are often quicker to assemble in comparison to alternative methods.
* They are 100% recyclable and inorganic meaning they will not warp, split, crack or creep.
* They offer the highest strength to weight ratio of any building material.
* Steel frames are not vulnerable to termites or any type of fungi or organism.
* They are dimensionally stable and do not expand or contract with moisture or temperature changes.
* Due to strict manufacturing controls, consistent material quality can be obtained due to production
taking place in line with strict standards.
* Steel is non-combustible so it will not contribute to the spread of a fire.
* Steel frames are lighter in comparison to concrete frames and will often benefit from a cheaper
foundation solution.
36
What are the technical disadvantages of steel frames?
* Steel frames require fire protection to be retrospectively installed.
* Fixing components may require replacement over time.
* The price of steel often fluctuates and can result in a lack of cost certainty.
* Installation of steel frames requires experienced builders at an additional cost. Resources can also be
difficult to acquire depending on market conditions.
37
What are the technical advantages of concrete frames?
* Fire protection is often provided inherently as part of the structure.
* Due to offering a slower form of construction in comparison to alternative methods, this will likely
result in reduced cash flow expenditure early on in the development.
* Maintenance requirements associated with concrete frames are relatively low in comparison to
alternative methods.
* Concrete frames often provide good sound and heat insulation properties in comparison to steel frame
constructions.
38
What are the technical disadvantages of concrete frames?
* In comparison to steel frames, they are more time consuming to install.
* There may also be complications during the install resulting from colder and inclement weather
conditions.
* The need for steel reinforcement can lead to issues around price fluctuations and cost uncertainty
associated with steel frames.
* Concrete frames are often heavier and require larger foundations.
39
Describe a typical Cold Flat Roof Construction
* The void or roof slab is insulated from heat loss from below and is therefore at a colder temperature
than the room below during cold weather.
* Insulation is located above ceiling level.
* Ceiling Joists form the main horizontal members and are fixed to the wall plates.
* Insulation is normally inserted between the roof joists with an air gap or void space being maintained to
allow for cross ventilation.
* There is a risk of condensation forming within the roof void or on the underside of the slab, so good
cross-ventilation is essential.
* Plywood decking is secured on to the joists and finished with the respective roof covering.
40
Describe a typical Warm Flat Roof Construction
* Insulation is placed on top of the roof deck but beneath the waterproof membrane.
* The vapour control layer is usually placed under the insulation.
* This reduces the risk of condensation as the ceiling or roof void is at a similar temperature to the roof.
41
Describe a typical Inverted Flat Roof Construction
* A roof in which the insulation is placed on top of the waterproof membrane.
* No vapour control is needed.
* The roof void and deck are maintained at similar temperature to the room.
* The insulation protects the membrane from damage but must be anchored down.
42
Describe a typical parapet wall – roof abutment detail
* The parapet wall or dwarf wall is built along the perimeter edge of the roof.
* The wall height extends above roof level.
* Where the wall intersects with the roof, a flashing or water proofing detail will be required along with a
DPC closer placed above the flashing and at the head of the wall under the coping detail.
43
Describe a pitched roof detail
Describe a pitched roof detail
* Pitched roofs typically are made up of rafters which span from the apex of the roof and are fixed to the
top of the external wall by a wall plate.
* At the apex of the roof are the ridge tiles which are supported by the ridge board.
* The roof covering whether slate or concrete tiles are typically fixed to roof battens.
* Supporting the rafters and roof coverings are the struts, purlins and roof beams.
* A soffit and eaves board may be fixed to the end of the rafters along with the guttering and rain water
goods.
* Vent tiles may also be used to provide natural ventilation to the roof space.
44
Describe a cladding rainscreen detail
* Rainscreen cladding provides a screening function rather than an enclosure in its own right.
* A rainscreen is used to shield a wall, whether this be of masonry, metal studwork or in some cases glass.
* Usually a rainscreen is designed to permit some controlled leakage with the main functions of resistance
to air and water being provided by the shielded wall behind
45
Describe a Cladding Stick System
* In the stick system, the curtain wall frame (mullions) and glass or opaque panels are installed and
connected together piece by piece.
* Stick curtain walling systems are versatile and allow for the integration of other systems, such as sliding
doors and windows. They tend to be less specialised and can be built by all types of fabricators as they
are not dependent on having a large factory.
* However, stick systems do require multiple steps to erect and seal the wall, which means more time is
spent on site – an approximate rule of thumb would be that 70% of the work is carried out on site,
with 30% in the factory. This incurs further costs due to additional labour time.
46
Describe a Unitised cladding system
* Unitised systems comprise narrow-width, storey-height units of aluminum framework containing
glazed and/or opaque insulated panels. The entire system is pre-assembled under factory-controlled
conditions.
* The unitised panels are usually craned into position, with pre-positioned brackets attached to the floor
slab or the structural frame. Modern installation techniques increase the speed of erection and often
minimise the requirement for scaffolding.
* Unitised systems do have higher direct costs despite their reduced labour time for the install.
47
Describe a Panellised systems
* Like unitised systems, panellised curtain walling is constructed in the factory to improve quality control
and speed of erection. However, the systems comprise large prefabricated panels of bay width and
storey height, which are connected back to the primary structural columns or to the floor slabs. Panels
may be of precast concrete or comprise a structural steel framework and are often clad with a variety of
stone, metal and masonry cladding materials.
* The advantage of these systems is improved adherence to specification as a consequence of factory
prefabrication, allowing improved control of quality and rapid installation with the minimum number
of site sealed joints. Panellised systems are less common and more expensive than unitised
construction.
48
49
50
What are the common components you would expect to see within a
steel frame construction?
* Beams.
* Columns.
* Purlins.
* Rafters.
Eaves.
* Eaves Haunch.
* Base Plate.
* Apex Haunch.
* Cladding Rails.
* Cross bracings.
* Fixings.
51
What are the common components you would expect to see within an
external wall / foundation detail?
* Strip foundation.
* Concrete block foundation wall.
* Rebar reinforcement.
* Damp Proof Course.
* Air bricks.
* Suspended floor slab or ground floor slab.
* Backfilling.
* Drainage.
52
What are the different parts of a steel beam?
* A simple I Beam is made up:
o Flange - top and bottom of the vertical steel.
o Web - which is the vertical steel part of the I beam.
o Root - where the flange and the web join.
53
What is powder coating?
* A durable factory applied coating on metals, such as aluminum or galvanized steel which is available in
many colours.
* This application is sprayed on and is followed by heat curing to give a film thickness of 50 to 100
microns.
* Any holes and cutting should be carried out before the coating is applied.
54
What is an RHS vs. SHS?
* RHS - Rectangular Hollow Section.
* SHS - Square Hollow Section.
55
What is intumescent paint?
* Fire Resistant paint that is sprayed on in the factory and touched up by hand on site.
* It works by stopping oxygen from reaching the surface of the material it is protecting.
56
What is an upstand?
* A vertical strip or skirting, such as the weatherproofing where roofing meets an abutment wall.
* It can be the roofing itself, particularly for mastic asphalt, the top part of a one-piece apron flashing, a
mortar skirting or an upstand flashing, and either stepped, raking or level.
57
What is post tensioned concrete?
What is post tensioned concrete?
* This method is usually employed where stressing is to be carried out on site after casting an insitu
component or where a series of pre-cast concrete units are to be joined together to form the required
member.
* In post-tensioning, concrete is cast around ducts or sheathing in which the tendons are to be housed.
* Stressing is carried out after the concrete has cured by means of hydraulic jacks operating from one of
both ends of the member.
58
What is formwork?
* Anything that holds fresh in-situ concrete in place until it hardens, such as plywood shutters, steel pan
forms, fibreglass moulds or profiled decking.
* Falsework holds the formwork in place and includes items such as accessories like wedges and clips for
tightening joints and to make stripping easy.
59
What is slip forming?
* A method for constructing a repetitive structure such as a core, lift shaft or stairwell.
* The formwork is constantly moving upwards during the installation.
* The concrete that becomes exposed must be cured enough to support the structure above.
60
What is jump forming?
* Jump forming is where a significant height of concrete is cast and left to cure.
61
In a brick block cavity wall, how are window openings dealt with in
terms of preventing water penetration and structurally?
* Preventing Water Penetration
o Cavity Trays are used which cross the 50mm wide cavity of a cavity wall, stepping up at least
150mm between the outer and inner leaves, to form a gutter that leads to a weephole in the
outer leaf.
o DPC (Damp Proof Course) – Is a strip of impervious material the same width as brickwork or
blockwork wall to stop moisture rising from the ground up the external leaf of the wall.
* Structurally
o Lintels are used which are a small beam installed over a window or door head which carry the
wall load above.
62
What is the size of a brick?
* Standard bricks are 215mm x 102.5mm x 65mm.
63
What is the frog and which side does it go on?
* The frog is an indentation in one of the bed faces of a brick, usually the top.
* Bricks with two frogs are known as ‘double-frogged’, though these are less common.
* Unless specifically stated, bricks should be laid frog (or larger frog) facing up, and with mortar filling the
frog.
* This gives a stronger wall and superior sound insulation.
64
How many bricks are in a m2?
There are about 60 bricks per m2.
65
What are the different types of brick bond?
* Stretcher – most commonly used with walls just a half brick wide.
* English – with alternating courses of headers and stretchers.
66
What other elements will be affected by the type of cladding systems
used?
* Frame.
* Roof.
* M&E.
67
What is an air brick?
* A perforated brick to allow for ventilation into a room or an underfloor space.
68
What are the factors that might affect the choice materials for internal
partitions?
* Fire rating requirements.
* Restriction for noise (Db ratings).
* Visuals – Opacity vs. transparency.
* Fixed or movable.
* Strength requirements.
69
What are the different types of screed?
* Bonded Screeds which are laid on to a ready prepared rough, cleaned concrete base.
* Unbonded Screeds which are laid on to a sound clean bitumen damp proof membrane.
* Floating Screed which is laid with steel or fibre reinforcements on to the insulating board, which in turn
can be laid on to a suitable damp proof membrane.
* Resin Bonded Screed which is laid on to a clean, rough pre-prepared concrete base. The resin acts as a
ready installed damp proof membrane to the top screed.
70
What is the purpose of a threshold strip?
* A lightly rounded metal strip over the joint between the floor finishes or coverings that meet under the
door leaf.
* They prevent fraying and provide an aesthetic finish which also interrupt combustible flooring under
fire doors.
71
What are the main components of a hipped end pitched timber roof
structure?
* Principle Rafters to provides support to the roof covering which span from eaves to ridge.
* Jack Rafters are shorter rafters that run from hip to eaves or ridge to valley.
* Ridge boards which provide support and run underneath the ridge.
* Wall plates receive the feet of rafters at the top of the external wall.
* Hip rafters where two roof surfaces meet to form an external angle.
* Valley rafter where two roof surfaces meet to form an internal angle.
* Purlins are intermediate horizontal members to support the rafters.
* Battens are small pieces of wood to which the roof covering is affixed.
* Coverings are either laid or fixed on to a roof to protect from the elements including clay, slate or
concrete roof tiles.
72
What are the elements of a flat roof?
* Joists which are fixed to wall plates to act as the main support.
* Furrings which are fixed to the top of joists to provide the required gradient of incline.
* Particle board is fixed to top of the furrings to provide a flat surface.
* Felt is applied usually made up of 3 layers and bonded with bitumen to provide a waterproof covering.
* Stone chippings provide protection to the felt and also reflect sunlight.
73
What kind of flat roof coverings and some of its
Pro’s and Cons’: Single layer membrane
* Single layer membranes
o Consists of one layer of felt with a base sheet of glass fibre or polyester reinforcement
impregnated with hot bitumen during manufacture.
o It is then coated both sides with a weatherproof bitumen compound and dusted with sand on
one layer and a thin layer of polythene on the other and left to cool.
o After cooling it is cut into strips ready for use.
o Single layer membranes are thin and easily punctured.
o Because of this they are rarely used commercially but form the cheapest option.
74
What kind of flat roof coverings and some of its
Pro’s and Cons’: Built-up membrane system
* Built up felt
o Is constructed using three layers of felt.
o The first is laid at right angles to the fall commencing at the eaves.
o The next is laid parallel to the fall and the final layer at right angles.
o It is then covered with stone chippings.
o Built up felt is more common but can be easily punctured if proper care is not taken.
75
What kind of flat roof coverings and some of its
Pro’s and Cons’: Asphalt?
* Asphalt roofing
o Mastic asphalt consists of an aggregate with a bituminous binder which is cast into block ready
for reheating at site. They are heated into cauldrons to a temp of 200 degrees C and are
transported in liquid form to the roof. Two coats are usually required.
o Asphalt roofs reduce risks of defects as it is poured on site rather than coming to site in rolls
which can be damaged in transport.
o Asphalt cools quickly and will need to be heated close to the roof.
o Heating anything to 200 degrees C is dangerous especially in a working environment.
o Asphalt roofs are hard wearing and are design to allow for transit over them.
o Some companies offer a 60-year guarantee due to their durability.
76
What items would you expect to find on a timber or part glazed door
that was required to have a half-hour fire rating?
* 3 hinges.
* Intumescent strip on door or edge of frame.
* A self-closing devise.
* If a glazing panel is present it must be 6mm thick, wired glass to a max of 1.2m2 with 13mm x 13mm
wood beads encased with non-combustible materials.
77
What is an MF ceiling?
The abbreviation MF commonly refers to a Mineral Fibre plasterboard suspended ceiling.
78
What is a metal grid ceiling and what are the benefits?
* This is a suspended ceiling system formed by a square grid.
* These are normally quicker to construct than alternative options and allow for service runs through the
void above therefore allowing greater floor to ceiling height. They also offer easy access for service
repairs.
* Damaged tiles can also be replaced rather than needing to repair the entire ceiling or replastering.
79
What is the difference between rolled and tiled carpet tiles and why do
we use each type?
* Rolled carpets generally offer better quality and are more expensive. Rolled carpet is commonly used in
dwellings.
* Carpet tiles are harder wearing and are often cheaper. Individual tiles can be replaced therefore they are
easier to maintain. Carpet tiles are commonly used in offices and hospitals. They are also used where
raised access flooring systems adopted to allow for easier access to services that run in the void below.
80
What is top down construction?
* “Top down” is used to speed up the construction process of a building with basement levels.
* The ground floor slab is cast with an access hatch.
* The ground below is excavated and another slab is formed. If there is another level, the process is
repeated. Piles are usually used as foundations and also act as retaining walls. It allows the building
above to be constructed at the same time as the basement.
81
What is bottom up construction?
* “Bottom up” forms the basement and then works upwards in a traditional manner. This offers a
simpler construction than top down methods of construction but will often carry a longer programme
duration.
82
What is a three phase electrical supply?
* A three phase supply is an AC (Alternating Current) supply that consists of three AC voltages 120
degrees out of phase with each other.
* Three phase electricity is cheaper and an easier way to transmit electricity compared to single phase
electricity.
83
Explain how power is distributed to floor boxes in a raised floor?
* The incoming power supply connects to a low voltage switchboard, which in turn connects to a
distribution board.
* The distribution board will have an under floor busbar connected to it. The busbar has a number of
sockets to which the floor box plugs into via a flexible lead. The floor box has sockets to which the
appliances can plug into.
84
What is Cat II lighting?
* Cat II Lighting are light fittings suitable for use with VDU screens. The light fittings should be designed
in such a way so as to limit the amount of glare from computer screens and such like.
85
What is a syphonic drainage system?
* A syphonic drainage system is an alternative to the gravity drainage system. In syphonic drainage, water
is sucked from the guttering in to the drain pipe so there is no need to have pipes set at a gradient and
to rely on gravity to pull the water to the drain (a vacuum is created to achieve this).
* Syphonic drainage has the advantage that narrower down pipes can be used.
86
Describe the different types of lift available?
* Passenger Lifts
o Passenger lifts can be specialised for the service they perform for example in hospitals with
front and rear entrances.
* Residential lifts
o Residential lifts may be small enough for one person while some are large enough for more
than a dozen.
* Platform Lifts
o Wheelchair or platform lifts are specialist lifts designed to move a wheelchair 2m or less they
can often accommodate just one person in a wheelchair at a time with a maximum load of
340kg.
* Freight Lifts
o Freight lifts are similar to passenger lifts but designed to carry goods. Passengers often travel
with the freight so most building regulations still apply.
o Freight elevators are typically larger and capable of carrying heavier loads than a passenger
elevator, generally from 2,300 to 4,500 kg. Freight Elevators may have manually operated
doors, and often have rugged interior finishes to prevent damage while loading and unloading.
o Although hydraulic freight elevators exist, electric elevators are more energy efficient for the
work of freight lifting.
* Dumbwaiter
o A small freight elevator is often called a dumbwaiter, often used for the moving of small items
such as dishes in a 2-story kitchen or books in a multi-story rack assembly.
o Dumbwaiters are generally driven by a small electric motor with a counterweight and their
capacity is limited to about 750 lb (340 kg). They may also be hand operated using a roped
pulley.
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What are automatic fire sprinklers?
* Automatic fire sprinklers are individually heat-activated and tied into a network of piping with water
under pressure.
* When the heat of a fire raises the sprinkler temperature to its operating point (usually 165ºF), a solder
link will melt or a liquid-filled glass bulb will shatter to open that single sprinkler, releasing water directly
over the source of the heat.
88
What are the main types of air-conditioning system available?
* Refrigeration Cycle
o In the refrigeration cycle, a heat pump transfers heat from a lower temperature heat source into
a higher temperature heat sink. Heat would naturally flow in the opposite direction. This is the
most common type of air conditioning. A refrigerator works in much the same way, as it
pumps the heat out of the interior into the room in which it stands.
* Evaporative Coolers
o The evaporative cooler is a device that draws outside air through a wet pad. The sensible heat
of the incoming air, as measured by a dry bulb thermometer, is reduced. The total heat
(sensible heat plus latent heat) of the entering air is unchanged. Some of the sensible heat of the
entering air is converted to latent heat by the evaporation of water in the wet cooler pads. If the
entering air is dry enough, the results can be quite comfortable. These coolers cost less and are
mechanically simple to understand and maintain.
* Absorptive Chillers
o Some buildings use gas turbines to generate electricity. The exhausts of these are hot enough to
drive an absorptive chiller that produces cold water. The cold water is then run through
radiators in air ducts for hydronic cooling.
89
Describe a VAV (Variable Air Volume) AC System?
* VAV systems vary the airflow at a constant temperature.
* These systems utilise a supply duct that distributes cooled air.
* The temperature is kept constant and the air flow varies to meets the rising and falling heat gains within
the thermal zone that is being cooled.
* The system is made up of supply and return ductwork, a VAV box also referred to as a VAV terminal
unit and air terminals.
90
Describe a VRF (Variable Refrigerant Flow) AC System?
* VRF systems can be made up of a heat pump system or heat recovery system which can provide
simultaneous heating and cooling.
* The heat pump is connected to multiple indoor units which can heat and cool independently of each
other.
* The energy recovered from one zone can be utilised to heat a separate zone meaning VRF systems are
more efficient in comparison to other systems.
* The system is made up of units a heat pump, a compressor and pipework that takes up much less space
than traditional ductwork.
91
How are fire barriers formed in suspended ceilings and what happens
when services pass through the barriers?
* If a suspended ceiling is not fire resistant, fire barriers will be required within the ceiling void if the walls
stop at the underside of the ceiling.
* The barriers will be installed between the soffit of the floor above and the suspended ceiling resulting in
the ceiling void being compartmented.
* It is also important to consider whether smoke stops are also required.
* When services run through the barriers it is important that they are sealed to prevent fire spreading
through the service gap.
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What is a UPS and why does a building require one?
* An uninterruptible power supply, or UPS, is a device or system that maintains a continuous supply of
electric power to certain essential equipment that must not be shut down unexpectedly.
* Typically, it is installed in hospitals for life critical equipment and in businesses for business-critical
equipment.
93
Why do we install generators in buildings?
* Generators are normally installed in buildings to act as a backup power supply should the primary
power supply fail.
* Generators in buildings for this reason are becoming less common as technical advances are made in
UPS.
94
What is Busbar trunking?
* Bare copper or aluminum conductors fixed inside trunking that distribute heavy-duty electrical power
to tap-off units.
95
What do the abbreviations FCU, AHU & VAV stand for?
* Fan Coil Unit (FCU).
* Air Handling Unit (AHU).
* Variable Air Volume System (VAV).
96
What types of bridge construction are there?
* Beam Bridge with simple beam or cantilever.
* Arch Bridge.
* Suspension Bridge or Cable Stayed Bridge.
* Moveable Bridge - Swing bridge, Draw bridge or Lift bridge.
97
How does a cable stayed bridge work?
* The load exerted from the bridge deck and all live loads are transferred through the wires to towers and
into ground anchorages.
98
What is the difference between a tower and a pier?
* The towers protrude through the deck vertically to provide a connection point for the cable stays which
transfer the load.
* Piers support the bridge deck.
99
What type of building work is covered by the Building regulations?
* The Erection or extension of a building.
* Installation or extension of a service that is controlled by the regulations.
* Alteration projects which will temporarily or permanently affect the building in terms of structure, fire
& access.
* Insertion of insulation into cavity walls.
* Underpinning building foundations.
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What are the specific areas covered by the Building Regulations?
* A) Structure.
* B) Fire Safety.
* C) Site preparation and resistance to moisture.
* D) Toxic substances.
* E) Resistance to the passage of sound.
* F) Ventilation.
* G) Hygiene.
* H) Drainage.
* J) Heat producing appliances.
* K) Protection from falling, collision and impact.
* L) Conservation of fuel and power.
* M) Access and facilities for disabled people.
* N) Glazing – safety in relation to impact, opening and cleaning.
* P) Electrical safety.
101
What are the Building Regulations Approved Documents?
* They provide general guidance on performance of materials expected in order to comply with the
functional requirements of the building regulations & provide practical examples.
* They only provide guidance & therefore there is no obligation to adopt specific solutions if it is possible
to meet requirements via a different means.
102
Who ensures the building regulations are complied with?
194
* Building Control Services such as the Local Authority or Approved Inspectors (Private companies set
up to specifically regulate building control).
103
What would be a typical programme for a new build structure?
* Site clearance.
* Enabling works.
* Site setup.
* Haul & access roads.
* Setting out.
* Excavate to reduced levels.
* Excavate foundations.
* Cast foundations.
* Frame erection.
* Cladding.
* Roof.
* Floors.
* Services.
* FF&E.
* Testing.
* Commissioning.
* Landscaping.
* Snagging.
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