Floor and Roof MCQ Quiz - Objective Question with Answer for Floor and Roof - Download Free PDF

Explanation:

The various components of the roof trusses are explained below;

• Principal rafter or Chord: The main member that forms the outline of a truss and is subjected to enormous axial force and bending moment. The principal rafter of a roof truss is designed as s continuous strut.
• Web: The members that connect the bottom and top chords to form a triangular shape are the webs of roof trusses.
• Node: The point of convergence of at least two members that make up the panels of a truss is referred to as a node.
• Joint: A joint is the point at which at least one web intersects with a chord.
• Apex: It is the highest point where the sloping top chords join together.
• Bottom Chords: These are the shortest longitudinal member of the roof trusses. The bottom chord member of the roof truss is known as the main tie or principal tie.
• Purlin: Purlins are beams that are provided over roof trusses to support the roof coverings. Purlins span between the top chords of two adjacent roof trusses and transmit the loads from roof coverings to the trusses.

Explanation:

The ratio of cement mortar used to fix tiles on the floor is 1:1.

Additional InformationThere is a different type of tiles used in building construction which are unique to the type of surface where it must be applied. Following are the types of tiles based on surface of application:

• Roofing tiles,
• Flooring tiles,
• Wall tiles, and
• Partition tiles.

 Procedure for laying of  floor tiles

• Firstly, levelled hard bed or 15 cm thick P.C.C is prepared.
• Over this bed, a thin layer of cement mortar 1:1 is laid.
• Then pre cast tiles of cement concrete or pottery are laid over it carefully, filling the joints with mortar, which are generally paper thick.
• Extra cement is wiped off and joints cleaned with saw dust. After curing the surface is rubbed and polished.

Explanation:

The various components of the roof trusses are explained below;

• Principal rafter or Chord: The main member that forms the outline of a truss and is subjected to enormous axial force and bending moment. The principal rafter of a roof truss is designed as s continuous strut.
• Web: The members that connect the bottom and top chords to form a triangular shape are the webs of roof trusses.
• Node: The point of convergence of at least two members that make up the panels of a truss is referred to as a node.
• Joint: A joint is the point at which at least one web intersects with a chord.
• Apex: It is the highest point where the sloping top chords join together.
• Bottom Chords: These are the shortest longitudinal member of the roof trusses. The bottom chord member of the roof truss is known as the main tie or principal tie.
• Purlin: Purlins are beams that are provided over roof trusses to support the roof coverings. Purlins span between the top chords of two adjacent roof trusses and transmit the loads from roof coverings to the trusses.

Explanation:

• Ridge is the horizontal line at the apex where two sloping sides of a roof meet.

• It is the highest point on a pitched roof and serves as a structural element that connects the sloping roof surfaces.

Explanation: Couple Roof

• In this type of roof the common rulers slope upwards from the opposite walls and they meet on a ridge in the middle.
• The common rafters are firmly secured in positions at the both ends, the one end being on the ridge piece and other on the wall plate.
• Such a roof is not very much favoured because it has the tendency to spread out at the feet, it usual plate level and it push out with a force the wall supporting the wall plate.
• A couple roof is suitable for span up to about 3.5 m.

The correct answer is Bay

Key Points

• Bay: The space between two adjacent trusses is commonly referred to as a "bay."
• Trusses are structural elements that consist of triangular units, and they are often used in the construction of roofs and bridges.
• The distance between two trusses is considered a bay, and this term is commonly used in structural engineering and architecture.

Additional Information

• Span: Span generally refers to the distance between two supports, such as the distance between two walls or two columns. It is not specifically associated with trusses but can be a more general term for the length of a structural element.
• Panel: A panel is a flat or curved component within a structure. It might be part of a wall, floor, or roof, but it doesn't specifically refer to the space between trusses.
• Pitch: Pitch is the incline or slope of a roof, typically expressed as the ratio of the vertical rise to the horizontal span. It's not directly related to the space between trusses.

Explanation:

Upper Floor:

• The floors constructed above the ground floor are known as the upper floors.

Additional InformationThe floor is mainly divided into two:

1 Ground Floor: These floors are directly rests on the ground surface.

2 Upper floor: Floors are classified based on types of materials and construction as follows:

The correct answer is Bay

Key Points

• Bay: The space between two adjacent trusses is commonly referred to as a "bay."
• Trusses are structural elements that consist of triangular units, and they are often used in the construction of roofs and bridges.
• The distance between two trusses is considered a bay, and this term is commonly used in structural engineering and architecture.

Additional Information

• Span: Span generally refers to the distance between two supports, such as the distance between two walls or two columns. It is not specifically associated with trusses but can be a more general term for the length of a structural element.
• Panel: A panel is a flat or curved component within a structure. It might be part of a wall, floor, or roof, but it doesn't specifically refer to the space between trusses.
• Pitch: Pitch is the incline or slope of a roof, typically expressed as the ratio of the vertical rise to the horizontal span. It's not directly related to the space between trusses.

Explanation:

Terrazzo flooring:

• It is a composite material that consists of chips of marble, quartz, granite, glass, or other suitable material, poured with a cementitious binder, polymeric, or a combination of both.
• Terrazzo is also known as Grano flooring due to its granolithic look.

Additional InformationGranite flooring:

• Granite flooring is purely made of granite, a type of igneous rock.
• It's very hard and durable.

IPS flooring:

• IPS stands for Indian Patent Stone.
• IPS is a type of floor finishing where cement concrete is used.

Mosaic flooring:

• Mosaic is a type of flooring typically seen in the form of tile, which consists of smaller pieces arranged to create a design. 

Explanation:

Rib floor

• In this type of floor, hollow blocks of clay or concrete are used to reduce the total weight of the floor. In one form, the blocks are placed 10cm apart and in this space, mild steel bars are placed.
•  A minimum cover of 80mm is kept at the top. Suitable flooring at the top and a sealing finish is provided.
• Rib floor is convenient to carry out plumbing and electrical installation without affecting the appearance.
• The blocks are provided with a rough or grooved surface so that they can develop enough bond with the concrete.
• This type of floor is economical, fireproof sound proof and light in weight. If properly designed, this type of floor can even be used to carry heavy loads.

Additional Information

R.C.C floor

• In this type of floor steel bars and concrete are used to form a floor. This type of floor is widely used in modern construction.
• The slab and beam are designed as per loading coming on the floor and proper reinforcement is placed at a suitable place.
• In the case of R.C.C. slab thickness varies from 80mm to 150mm and the main reinforcement is generally in the form of mild steel bars of diameter varying from 9 mm to 12 mm.

Timber floor

In this floor, only timber is used as a material. Timber floors are further divided into four types.
a. Basement or Ground floor of timber
b. Single Joist timber beam
c. Double Joist timber beam
d. Framed triple joist timber floor.

Jack arch floor

• In this type of floor, brick arches or cement concrete arches are constructed and these arches rest on the lower flanges of mild steel joists.
• The joists in turn rest either on the wall or on the beam.
• The joists are placed at a distance of about 80cm to 120cm from centre to centre. The rise of the arch should be 10cm to  20cm. and the minimum depth of concrete at the crown should be 15cm.
• The only disadvantage of this floor is that it does not give a plain ceiling surface
  

Explanation:

R.C.C floor

• ​These R.C.C or R.B. flat roofs are constructed in a similar way as R.C.C or R.B. floors except that they are required to be protected against weather elements, i.e, rain, snow, and heat.
• A protective covering, consisting of a 10 cm thick layer of lime concrete terracing with some waterproofing compound is provided over the R.C.C or R.B. slab. This layer makes the roof leak-proof.
• The layer of lime concrete is thoroughly beaten by hand beaters to make it hard, impervious and compact.
• At the junction of the wall, the lime concrete terracing is taken inside the wall for a depth of 10-15 cm and the corner is given a round smooth finish. This is done to prevent the accumulation and leakage of
  water at junctions.
• The lime terracing is provided with a little slope, usually 1 in 60 to 1 in 100, to drain off the rainwater rapidly and easily.

Additional Information

The type of flat roof construction is as follows:

1. Mud Terrace Roof,
2. Brick- Concrete Terrace Roofs (Including Madras Terrace Roof)
3. Jack Arch Flat Roofs,
4. R.C.C or Reinforced Brick Slab Roofs, and
5. Bengal Terrace Roofs.

Explanation: Couple Roof

• In this type of roof the common rulers slope upwards from the opposite walls and they meet on a ridge in the middle.
• The common rafters are firmly secured in positions at the both ends, the one end being on the ridge piece and other on the wall plate.
• Such a roof is not very much favoured because it has the tendency to spread out at the feet, it usual plate level and it push out with a force the wall supporting the wall plate.
• A couple roof is suitable for span up to about 3.5 m.

Explanation:

• 10-15 mm: This thickness is generally too thin for an asphalt layer to provide sufficient durability for flooring.

• 20-30 mm: This range is suitable for light-duty applications and general flooring purposes.

• 30-40 mm: This thickness may be used in areas with slightly heavier loads.

• 85 mm: This thickness is generally used for roads and pavements with heavy-duty requirements.

Explanation:

30 cm is the centre-to-centre distance of the joist in the Brick concrete terrace roof.

Brick Concrete Terrace Roof

• Brick Concrete Terrace roofs are used in places where the rainfall is heavy. 
• The girders of adequate sizes are placed across the room over the wall on girders or plates of wood or stone at regular intervals of 1.2 to 2.5 metres.
• Above these, the joists are placed at right angles to beams at a spacing of 30 cm centre-to-centre.
• Either two courses of flat tiles or one course of bricks are laid and set in lime or cement mortar.

Additional Information

Bengal terrace:​

• As this type of roof is generally used in Bengal state to cover verandahs joists it is known as the Bengal terrace roof.

Explanation:

North light roof

• These shell roofs are useful for big structures such as factories these are used in northern area.

Additional Information

Belfast truss

• This truss is in the form of a bow which consists of thin sections of timber which its top chord curved. If the roof covering is light roof truss can be used for up to 30 m span. The roof truss is also known as latticed roof truss.

Truncated truss

• ​This truss is just similar to the mansard truss except that the top is finished flat with a gentle slope to one side. It is used when a room is required in the roof.

Bow String truss