Construction Materials Questions and Answers for Aptitude test on “Dampness”.
1. In order to prevent the entry of damp into a building, the course are provided are known as the ________ course.
a) Termites proofing
b) Water proofing
c) Corrosion proofing
d) Damp proofing
Answer: d
Clarification: The Damp proofing courses are provided at various levels of entry of damp into a building. At present, practically all the buildings are given the treatment of damp proofing. Thus, the provision of damp proofing courses prevent the entry of moisture from the walls, floor and basement of a building.
2. Due to ______________ the dampness finds its way to the floors through the substructure.
a) Action of rain
b) Exposed tops of walls
c) Raising of moisture from ground
d) Condensation
Answer: c
Clarification: The ground on which the building is constructed may be made of soils which easily allow the water to pass. Usually the buildings material used for the foundation absorb moisture by capillary action. Thus, the Dampness finds his way to the floor through the substructure.
3. Due to ________ the external faces of wall become the sources of entry of dampness in a structure.
a) Exposed tops of walls
b) Miscellaneous causes
c) Action of rain
d) Condensation
Answer: c
Clarification: If faces of wall, exposed to heavy showers of rain, not suitable protected, they become the sources of entry of the dampness in a structure. Similarly, the leaking roof also permits the rain water to enter the structure.
4. ________ is the main source causing dampness in badly designed kitchens.
a) Action of rain
b) Condensation
c) Exposed tops of walls
d) Miscellaneous causes
Answer: b
Clarification: The process of condensation takes place when the warm humid air is cooled. This is due to the fact that cool air can contain less invisible water vapours than warm air. The moisture is a deposit on the walls, floor and ceiling. This is the main source causing dampness in badly design kitchens.
5. __________ is a flexible material and it is easy to lay & is available in rolls of normal wall width.
a) Hot bitumen
b) Metal sheets
c) Mastic asphalt
d) Bituminous felts
Answer: d
Clarification: The Bituminous felts can accommodates slight moments. But it is liable to squeeze out under heavy pressure and it offers little Resistance to sliding. The material is available in rolls and it should be careful unroll, especially in cold weather.
6. ________ is a semi-rigid material and it forms an excellent impervious layer of damp proofing.
a) Hot bitumen
b) Mastic asphalt
c) Bituminous felts
d) Metal sheets
Answer: b
Clarification: The good Mastic asphalt is a very durable and completely impervious material. It can be withstand only very slight distortion. It is liable to squeeze out in very hot climates or under very heavy pressure. It should be laid by experience men of the specialist firms.
7. ________ is a flexible material and is placed on the bedding of concrete or mortar.
a) Mastic asphalt
b) Hot bitumen
c) Bituminous felts
d) Metal sheets
Answer: b
Clarification: Hot bitumen is a flexible material and is placed on the bedding of concrete or mortar. This material should be applied with a minimum thickness of 3 mm.
8. The _________ of lead, Copper and Aluminium can be used as the membrane of damp proofing.
a) Metal sheets
b) Bituminous felts
c) Mastic asphalt
d) Hot bitumen
Answer: a
Clarification: The lead sheet is a flexible material. The thickness of lead sheet should be such that its weight is not less than 200 N/m2. The lead can be dressed to complex shapes without facture and it possesses high resistant to sliding action.
9. __________ material is made of black polythene having a thickness of about. 50 mm to 1 mm.
a) Brick
b) Stone
c) Plastic sheet
d) Cement concrete
Answer: c
Clarification: The plastic sheets are made of black polythene having a thickness of about 0.50 mm to 1 mm with usual width of wall and it is available in roll length of 30 metres. This treatment is relatively cheap but it is not permanent.
10. A _________ layer is in proportion 1:2:4 is generally provided at the plinth level to work as a damp proofing course.
a) Mortar
b) Cement concrete
c) Stone
d) Brick
Answer: b
Clarification: The depth of cement concrete layer varies from 40 mm to 150 mm. It stops the rise of water by capillary action and it is found to be effective at places where them is not excessive.
11. __________ absorbing water less than 4.50% of their weight can be used for Damp proofing.
a) Bricks
b) Mortar
c) Stones
d) Cement concrete