Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CT > ROOFS (mainly low sloped) > Flashcards

ROOFS (mainly low sloped) Flashcards

1
Q

What are the functional requirements of a roof?

A

Strength and Stability:

Must support dead and live loads (e.g., snow, wind).

Weather Resistance:

Protects against elements like snow, wind, and rain.

Thermal Insulation:

Manages solar gain, heat loss, cold air ingress, air leakage, and thermal expansion/contraction.

Fire Resistance:

Prevents fire spread, supports safe escape routes, and maintains structural integrity.

Sound Insulation:

Mitigates noise from weather, traffic, and internal activities.

Floor Space:

Utilizes roof space for additional purposes (e.g., mechanical plants, gardens, helipads).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a roof?

A

In UK construction, a roof structure refers to the framework that supports the roof covering and transfers its weight to the building’s walls or supports.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the types of roof structures?

A

Flat and Pitched Roofs:

Pitched roofs have slopes greater than 10°.
Flat roofs have less than a 10° slope and include monopitch, curved, and duopitch structures.

2D and 3D Structures:

2D: Beams, arch ribs, trusses.
3D: Parabolic shells, space frames.
Long and Short Span Roofs

Classified by span length: short (0-8m), medium (8-25m), long (25m+).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the aspects of a Flat/Low Pitch Roof Structure?

A

Components:

May include glass (structural or framed glazing), rooflights, or green roofs.

Green Roofs:

Store significant water, enhance environmental performance, come in intensive and extensive types.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the cost and lifespan for flat roof components?

A

Cost and Lifespan:

Various materials have different costs and lifespans. For example:

Clay tiles: £33-93/m², lifespan 100 years.

Natural slate: £50-160/m², lifespan 150 years.

Bitumen felt (2 layers): £30-35/m², lifespan 15 years.

PVC: £70-80/m², lifespan 25-30 years.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What considerations must be taken when working on roofs?

A

Safety:

High-risk trade with potential for falls and environmental hazards.

Adherence to CDM regulations and health/safety standards is crucial.

Modern Methods:

Includes Structural Insulated Panels (SIPS).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a flat roof?

A

Definition: Roofs with a slope of less than 10 degrees.

Uses: Often used in commercial buildings, extensions, and modern residential designs.

Common Materials: Built-up felt, single-layer membranes, mastic asphalt, and metal roofing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a pitched roof?

A

Definition: Roofs with a slope greater than 10 degrees.
Shapes: Includes gabled, hipped, mansard, and gambrel roofs.

Uses: Predominantly used in residential buildings due to their ability to shed water and snow effectively.

Common Materials: Tiles (clay or concrete), slates, shingles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are components of roof structures?

A

Trusses, Beams, Purlins, Joists, Roof Decking and Fascia/Soffit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a Truss roof structure?

A

Trusses

Definition: Pre-fabricated triangular wooden frameworks that provide support and distribute weight evenly.

Types: Various designs such as king post, queen post, fink truss, and attic truss.

Use: Common in both residential and commercial buildings for pitched roofs.
Beams and Rafters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are beams/rafters in roofs?

A

Beams:

Horizontal structural elements that support the roof and transfer loads to the vertical supports.

Rafters:

Sloping beams that run from the ridge to the eaves, providing the primary support for the roof covering.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are purlin roofs?

A

Purlins

Definition: Horizontal beams that provide intermediate support to rafters.

Placement: Typically placed parallel to the ridge and eaves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are joists?

A

Joists

Definition: Horizontal beams that support the ceiling below the roof.

Use: Provide additional support to the roof structure and help in distributing loads.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is roof decking?

A

Roof Decking

Definition: The surface, usually made of plywood or OSB (oriented strand board), that provides a base for the roof covering.

Use: Supports the roof covering and adds rigidity to the roof structure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are Fascia and Soffit roofs?

A

Fascia and Soffit

Fascia: A vertical board running along the edge of the roof, typically where the gutter is attached.

Soffit: The horizontal board under the eaves, providing ventilation and a finished look.
Underlayment

Definition: A protective layer installed between the roof decking and the roof covering.

Use: Provides additional waterproofing and protection against elements like wind and moisture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What construction aspects must be considered when making roofs in the uk?

A

Building Regulations:

Roof structures must comply with UK building regulations, ensuring they meet standards for structural integrity, thermal performance, fire safety, and ventilation.

Weather Considerations:

The UK climate necessitates that roofs are designed to handle rain, snow, and wind. Pitched roofs are common due to their efficiency in shedding water and snow.

Insulation and Ventilation:

Adequate insulation is critical for energy efficiency and preventing heat loss. Ventilation is also essential to prevent condensation and maintain air quality within the roof space.

Fire Resistance:

Materials and design must provide fire resistance to prevent the spread of fire and allow for safe evacuation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the modern roof trends present in the uk?

A

Green Roofs: Incorporation of vegetation on flat or slightly pitched roofs to improve insulation, reduce stormwater runoff, and enhance biodiversity.

SIPs (Structural Insulated Panels): Used for efficient, quick construction with excellent thermal properties.

Sustainability: Increased use of sustainable and recycled materials to reduce environmental impact.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the functional requirements of a low sloped roof?

A

Strength and Stability: Must withstand deflection.

Weather Resistance: Protects against wind and rain.

Thermal Insulation: Controls heat loss and gain.

Fire Resistance: Protects from fires above and below.

Sound Insulation: Reduces noise inside and outside.

Space Utilization: Can provide service space, recreation space, or parking.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are Low Sloped roofs used for?

A

Low-slope roofs have a slope of less than 10 degrees, with BS6229 recommending a design fall of 1 in 40.

Traditionally used in hot climates; less common in northern climates before the late 19th century.

20
Q

What are the primary components of a flat roof?

A

Primary Structure: Frame

Secondary Structure: Additional beams

Decking

Screed

Vapour Barrier

Insulation

Waterproofing

Paving

Accessories

Drainage

21
Q

What are roof joists?

A

Various construction methods include plywood over wood joists, solid wood decking, corrugated steel decking, in-situ concrete, and pre-cast concrete.

The deck must be stiff, resistant to wind uplift, and slope adequately towards drainage points.

Slope creation methods include sloped beams, tapered fill, or rigid insulation boards.

Proper slope prevents water ponding and structural collapse.

Movement joints are necessary to manage expansion and contraction.

22
Q

What is thermal insulation and vapour barrier in a low pitched roof?

A

Insulation Locations:

Below the deck (“cold roof”)

Between the deck and membrane

Above the membrane (protected membrane roof)

Insulation Materials: Mineral or glass fiber, rigid panels, or lightweight screeds.

Vapour Barriers: Prevent condensation by being placed where it will always be warmer than the dew point.

23
Q

What are the types of roof membrane?

A

Built-up Roof Membrane: Layers of felt and bitumen, protected with aggregate.

Single-ply Membrane: Sheet materials (neoprene, EPDM, PVC) applied in a single layer, fixed with adhesives, ballast, or fasteners.

Fluid-applied Membrane: Rolled or sprayed materials like neoprene, silicone, polyurethane for complex shapes.

24
Q

What are the types of roof covering?

A

Sheet Membrane: Modified bitumen or synthetic polymers.

Liquid Membrane: Hot or cold applied asphalt and synthetic resins.

Metal: Corrugated steel, copper, aluminium, stainless steel.

Glass: Used in specific architectural applications.

Green Roofs: Incorporating vegetation for environmental benefits.

25
Q

What are the construction aspects that must be considered when creating a low pitched roof?

A

Cost: Varies by material (e.g., concrete tiles £21-44/m², clay tiles £33-93/m²).

Life Span: Depends on material (e.g., clay tiles 100 years, bitumen felt 15-30 years).

Safety: High-risk due to falls, weather conditions; requires compliance with CDM regulations and HSG33.

26
Q

What are the two forms of liquid membrane?

A

Liquid Membrane:

  • Hot Applied
    – Asphalt (natural bitumen)
    – Refined bitumens, SBS, synthetic rubber and mineral stabilizers (elastomeric - stretch)
  • Cold Applied:
    – Protec - Polyester resin
    – Polyroof – ‘Elastex’ Polyurethane resin
27
Q

What are the two forms of sheet membrane?

A
  • Bitumen felt:

– Modified with natural rubber, styrene
– Bauder- Bauderflex, Airtech, BTRS

  • Single ply systems (synthetic polymers):

– Fatra – mesh reinforced PVC
– Sarnafil - glass fibre core, two coats of Plastisol
– Bauder Thermaplan – flexible polyolefin (FPO)
– Bauder Thermofol– polyester reinforced laminated
PVC

28
Q

What are traffic decks in roofs?

A

These are installed over flat roof membranes for
walks, roof terraces and sometimes driveways
or parking surfaces.

29
Q

What is Ballasting in Roofs?

A
  • Ballast serves to hold roof membranes down
    against wind uplift.
  • It also protects from UV light wear degradation.
  • It contributes to the fire resistance of a roof
    covering.
  • It resists mechanical wearing and impact
30
Q

What is a fluid applied roof-membrane?

A
  • These are used primarily for domes, vaults and
    other complex shapes that are difficult to roof
    by conventional means.
  • Such shapes are too flat on top for tiles but too
    steep on the sides for built-up roof membranes -
    and if doubly curved are difficult to fit with
    single-ply membranes.
31
Q

What are Polymer-modified bitumens?

A
  • These are sheets composed of bituminous
    materials to which polymeric compounds have
    been added to increase their flexibility,
    cohesion, toughness and resistance to flow.
  • Most are reinforced with fibres, fibrous mats or
    plastic films.
  • Thickness ranges from 1.0mm to 4.0mm.
32
Q

What are the properties of Chlorinated polyethylene and chlorosulphonated polyethylene?

A
  • These are highly resistant to UV attack.
  • It can be manufactured in light, heat reflective
    colours.
  • It is used mainly on roofs where ballasting is
    unacceptable because of appearance or
    excessive slope.
33
Q

What is PVC?

A

Polyvinyl chloride.

  • This is also relatively low cost.
  • Thickness 1.15mm to 1.5mm.
  • Seams are sealed either by solvent welding or
    by hot air welding.
  • It may be laid loose, stuck or mechanically
    fastened to deck.
  • It can be used in a protected membrane roof.
34
Q

What is EPDM?

A
  • Ethylene propylene diene monomer
  • This is the most widely used single-ply roof
    membrane.
  • It is relatively low cost.
  • Thickness 0.75mm to 1.5mm.
  • It is joined with adhesive.
35
Q

What is Neoprene?

A
  • This is a high performance synthetic rubber
    compound.
  • It is applied in sheets 0.75mm to 3.0mm thick
    and joined at the seams with an adhesive.
  • It is vulnerable to UV attack and is therefore
    coated with a protective layer of chlorosolphonated polyethylene.
36
Q

What is a Single-ply roof membrane?

A
  • These are a diverse and rapidly growing group
    of sheet materials that are applied in a single
    layer.
  • The obviously require less on-site labour than
    built-up membranes and are usually more
    elastic and therefore less prone to cracking and
    tearing.
37
Q

What is a Built-up roof membrane?

A
  • This is comprised of multiple layers of roofing
    felt bedded in bitumen.
  • The bitumen is applied hot to merge with the
    saturant bitumens in the felt and so form a single-piece membrane.
38
Q

What are the three forms of roof membrane?

A
  • These fall into 3 categories:

– Built-up roof membrane
– Single ply membrane
– Fluid applied membrane

39
Q

What is a Vapour Barrier?

A
  • The vapour barrier must be located at such a
    point in the roof assembly that it will always be
    warmer than the dew point of the air under any
    conceivable condition of use.
  • the dew point (Tdp) is the temperature at which
    water vapor just starts to condense out of air
    that is cooling.
  • Usually this means putting the vapour barrier
    below the insulation.
40
Q

What are Ceilings?

A

Functions of Ceilings & Ceiling Spaces:

Ceilings impact building effectiveness and indoor environmental quality.

Challenges include balancing color, texture, and shape without compromising performance or increasing cost.

Acoustical performance directly affects productivity and health.

Ceilings impact indoor air quality, energy efficiency, and building operations.

Innovations in ceiling design improve safety and efficiency, affecting return on investment (ROI).

Ceilings distribute conditioned air, light, electrical energy, water supply, communications wiring, and sound.

Visual impact influenced by color, texture, pattern, and shape.

41
Q

What are the common types of ceilings?

A

Exposed Structural and Mechanical Components.

Tightly Attached Ceilings.

Suspended Ceilings.

Interstitial Ceilings.

42
Q

What are tightly attached ceilings?

A

Various materials tightly attached to joists or slabs.
Special arrangements needed for protruding beams, ducts, and conduits.

Detailed instructions available in Gyproc Ceiling Installation Guide.

43
Q

What are suspended ceilings?

A

Hangs below floor or roof structure on wires.
Allows level installation despite structural elements above.

Contains ducts and conduits in the plenum space.

Commonly made of materials like gypsum plasterboard or incombustible fibers.

Offers flexibility in design, accessibility, and fire protection.

Different materials supported by steel framing members.

Supports various fixtures and provides sound absorption.

Acoustical ceilings less expensive than traditional options.

Must meet fire resistance standards and installation guidelines.

44
Q

What are Interstitial Ceilings?

A

Dedicated to mechanical equipment in large buildings.

Common in hospitals, laboratories, and lecture facilities.

Accommodates elaborate services and requires continual maintenance.

Facilitates building remodelling and cost-effective renovations.

Suspended at a level for workers to access the plenum space.

Increases overall building height and supports various finishes.

45
Q

What are Ceiling Panel Finishes?

A

Metal panels and embossed metal ceiling panels offer aesthetic appeal.

Wood ceilings available in various panel types and designs.

Beware of polystyrene/Styrofoam tiles due to fire hazard.

46
Q
A

CT (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions