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The eaves of a timber flat roof for a bathroom is constructed as shown in the sketch - Leaving Cert Construction Studies - Question 1 - 2013
Question 1
The eaves of a timber flat roof for a bathroom is constructed as shown in the sketch. The roof is covered with layers of bituminous felt on plywood decking on 200 mm... show full transcript
Worked Solution & Example Answer:The eaves of a timber flat roof for a bathroom is constructed as shown in the sketch - Leaving Cert Construction Studies - Question 1 - 2013
Step 1
To a scale of 1:5, draw a vertical section through the eaves of the flat roof and through the external wall.
Answer
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Start by drawing a vertical line to represent the section width. This line should be proportionate to the scale selected, specifically 1:5.
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Illustrate the roof structure beginning with the outermost layer, which includes three layers of bituminous felt, followed by plywood decking measuring 18-25 mm.
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Below the decking, depict the counter battens and the roof joists which are 200 mm × 50 mm placed at 450 mm centres.
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Indicate the insulation layer, specifying that it’s 150 mm in thickness to comply with current Building Regulations.
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Include the plasterboard ceiling below and finish the section with the external wall, detailing the 350 mm concrete block wall.
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Ensure to include dimensions where required:
- Distance from the wallplate to the edge of the joist
- Total height of the wall
- Thickness of the insulation
- Length of the fascia so that it shows variations clearly. Each measurement should be clearly marked on the drawing to match the 1.5 m representation of the roof joist.
Step 2
On your drawing, show how rainwater is removed from the flat roof.
Answer
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Illustrate a drip edge formed from a material of 50 mm × 25 mm attached to the fascia. This serves as a channel for rainwater.
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Show the direction of water flow beginning from the roof surface, moving towards the eaves gutter, which should be appropriately sized to capture the water.
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Depict how the eaves gutter is fitted directly under the drip edge and is sealed to ensure no leakage occurs.
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Add a downpipe connected to the eaves gutter that directs the collected water downwards and away from the building's foundation.
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Make sure to clearly label all parts of the drainage system including the gutter, downpipe, and drip edge, along with arrows to indicate the direction of water flow for clarity.