This set of Repair and Rehabilitation of Structures Multiple Choice Questions & Answers (MCQs) focuses on “Damp Proofing Treatment for Roofs and Parapet Wall”.
1. Flat roof requires very costlier water proofing treatment when compared with pitched or sloped roofs.
a) True
b) False
View Answer
Explanation: Because of the stagnation of water in flat roofs the effect of dampness is very high when compared to pitched and sloped roofs and so costlier water proofing treatment is to be adopted, to avoid dampness.
2. In case of damp proofing treatment is given to flat roofs the slope to be maintained is ______
a) 1:20 to 1:30
b) 1:50 to 1:60
c) 1:40 to 1:60
d) 1:10 to 1:20
View Answer
Explanation: To avoid the stagnation of rain water in flat roofs proper roof slopes and rain water pipes should be given to avoid dampness and the grading slope adopted for this is 1:40 to 1:60 which is achieved by varying the thickness of the materials that are used for constructing the terrace.
3. Water drain pipes of _____ diameter is used flat roofs to drain the rain water.
a) 40 cm
b) 10 cm
c) 15 cm
d) 50 cm
View Answer
Explanation: To avoid the stagnation of rain water in flat roofs proper rain water pipes should be given to avoid dampness and usually the drain pipes are of diameter 10 cm and they are provided for every 30 sq.m of the roof area which is to be drained.
4. In cases where thermal insulation is not required _______ bitumen felts are used.
a) acyclic
b) acetylene
c) hessian
d) acetone
View Answer
Explanation: In places where thermal insulation is not taken into account the problem of providing slopes in flat roofs can be tackled by using hessian based bituminous felts as a water proofing treatment.
5. Four course treatment of damp proofing in flat roofs are adopted for _________ climate.
a) moderate
b) severe
c) winter
d) rainy
View Answer
Explanation: Four course treatment of damp proofing in flat roofs are adopted where the climate is moderate and here the bitumen is laid at a rate of 1.2 kg/m2 on the surface of the roof in four courses.
6. Six course treatment of damp proofing in flat roofs are adopted for _________ climate.
a) moderate
b) severe
c) winter
d) rainy
View Answer
Explanation: Six course treatment of damp proofing in flat roofs are adopted where the climate is severe and here the bitumen is laid at a rate of 1.2 kg/m2 on the surface of the roof in six courses.
7. Which of the following is not adopted as a damp proofing treatment for flat roofs?
a) Providing RCC floors and wall slabs
b) Grading of lime concrete
c) Grading of lime phuska with tiles
d) Grading of mud phuska with tiles
View Answer
Explanation: Providing RCC floors and wall slabs are considered as damp proofing treatment to the basement in damp soil and remaining are the damp proofing treatment for flat roofs that are adopted in various regions of the country.
8. In case of small roof penetrations UV stable glands are used to seal the penetration.
a) True
b) False
View Answer
Explanation: When there is small roof penetration UV stable gland are used to seal the penetration and this product seals the conduit entering the roof space using UV stabilized silicon.
9. Membrane roofing is adopted for low sloped roofs.
a) True
b) False
View Answer
Explanation: In case of low sloped roofs membrane roofing is adopted to seal the leakages and also to move the water off the terrace thereby preventing the entry of dampness into the building.
10. The parapet wall is protected by providing _________
a) bituminous membrane
b) liquid water membrane proofing
c) cementitious water proofing
d) coping of bricks
View Answer
Explanation: The parapet wall is protected by providing coping of the bricks where the coping acts as a slope to drain the rain water that falls on them thereby preventing the entry of rain water into the building.
11. Dry rot is caused by lack of ________
a) ventilation
b) water proofing
c) sand layer
d) coping of bricks
View Answer
Explanation: Due to lack of ventilation dry rot is developed at the center of the roof where the plywood gets crumbled due to the moisture and is prevented by installing a ridge vent.
Sanfoundry Global Education & Learning Series – Repair and Rehabilitation of Structures.
To practice all areas of Repair and Rehabilitation of Structures, here is complete set of Multiple Choice Questions and Answers.
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