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A dwelling house has a traditional cut roof pitched at 45°, as shown in the sketch - Leaving Cert Construction Studies - Question 5 - 2014
Question 5
A dwelling house has a traditional cut roof pitched at 45°, as shown in the sketch. The roof is covered with concrete tiles, which are supported on 200 mm × 50 mm ra... show full transcript
Worked Solution & Example Answer:A dwelling house has a traditional cut roof pitched at 45°, as shown in the sketch - Leaving Cert Construction Studies - Question 5 - 2014
Step 1
To a scale of 1:5, draw a vertical section through the portion of the roof at the ridge.
Answer
Begin by creating the overall triangle shape of the roof. For a scale of 1:5, each 100 mm in reality equates to 20 mm on paper. Draw the ridge line at the peak of the triangle, marking it appropriately.
From the ridge, illustrate the ridge tile, ensuring it extends beyond the sides of the roof slightly for rain runoff. Next, depict the rafter system with the rafters spaced at 200 mm apart, showing that they are 50 mm in depth. Indicate the collar ties, positioned at a height of 150 mm below the ridge.
Include three courses of tiles resting upon the battens. Each tile should be represented accurately, considering the width is around 50 mm. Label all components clearly: the ridge tile, collars, rafters, batchers, and tiles. Finally, include three typical dimensions such as the height from the base to the ridge, the angle of 45°, and the spacing of the collar ties.
Step 2
On your drawing, show one method of ventilating the roof structure.
Answer
Indicate a ridge vent at the top of the roof drawing. This vent allows warm air to escape from the attic space, thus preventing heat buildup. Additionally, show ventilation openings near the eaves or soffit, which permit cooler air to enter the structure. Explain through a note that this method helps in maintaining air circulation, which is crucial for preventing moisture accumulation and promoting durability of roofing materials.