Photo AI
2. (a) Using notes and freehand sketches, discuss three functional requirements of an external wall for a new dwelling house - Leaving Cert Construction Studies - Question 2 - 2015
Question 2
2. (a) Using notes and freehand sketches, discuss three functional requirements of an external wall for a new dwelling house. (b) Using notes and freehand sketches,... show full transcript
Worked Solution & Example Answer:2. (a) Using notes and freehand sketches, discuss three functional requirements of an external wall for a new dwelling house - Leaving Cert Construction Studies - Question 2 - 2015
Step 1
Using notes and freehand sketches, discuss three functional requirements of an external wall for a new dwelling house.
Answer
-
Weather Protection: An external wall must effectively protect the occupants from harsh weather, including rain, wind, and snow. This involves ensuring that the materials used are water-resistant and can withstand various weather conditions. Additionally, the wall must prevent moisture ingress, which could lead to dampness and mold growth inside the dwelling.
-
Thermal Insulation: The wall should maintain a comfortable indoor temperature by providing adequate insulation. This is crucial in energy conservation, as it reduces the reliance on heating and cooling systems. Common materials used for insulation include fiberglass, foam board, and insulated concrete forms (ICFs).
-
Structural Integrity: The external wall must bear and distribute the loads from the roof and upper floors while providing stability to the structure. It should be designed to withstand lateral forces such as wind loads, ensuring the safety and longevity of the dwelling.
Step 2
Using notes and freehand sketches, show the design detailing of three different, distinct external wall types suitable for a new dwelling house.
Answer
-
Concrete Block with Insulated Cavity:
- Materials: Concrete blocks, insulated cavity filling (such as foam).
- Dimensions: Standard concrete block size (400mm x 200mm) with a 50mm cavity for insulation.
- Design Detail: The wall structure includes a damp-proof course and is finished with a weatherproof exterior cladding.
-
Timber Frame with Exterior Weatherproof Cladding:
- Materials: Timber frame, insulation (fiberglass or spray foam), and weatherproof cladding (such as vinyl or wood).
- Dimensions: 2x4 timber framing with 90mm insulation, covered by 18mm exterior cladding.
- Design Detail: The timber frame is built with treated wood and incorporates ventilation gaps to prevent moisture buildup, along with a breathable membrane.
-
Straw Bale Wall:
- Materials: Straw bales, plaster or adobe finish.
- Dimensions: Standard straw bale size (1200mm x 450mm x 300mm).
- Design Detail: The straw bales are stacked and compressed, then plastered for a smooth finish. This type of wall provides excellent thermal insulation and is eco-friendly.
Step 3
Evaluate the design of any two of the wall types at 2(b) above. Recommend a preferred external wall type for a new house and justify your recommendation.
Answer
-
Concrete Block with Insulated Cavity:
- Evaluation: This wall type offers strong structural integrity and excellent thermal performance when insulated properly. The longevity of concrete makes it a durable option, but care must be taken to manage moisture.
-
Timber Frame with Exterior Weatherproof Cladding:
- Evaluation: This design allows for a quicker build time and flexibility in terms of design and insulation choices. However, it requires more maintenance over time in terms of checking for rot and ensuring water doesn't penetrate.
Recommendation: I would recommend the Concrete Block with Insulated Cavity as the preferred external wall type for a new house. This option provides a robust structure with better moisture management, energy efficiency, and durability, which are crucial for long-term performance and low maintenance costs.