WEEK 08 ACTIVITY: ‘IN DETAIL’ (PART ONE) CASE STUDY BUILDING: OVAL PAVILION 640423
1. Loose insulation
1 2 4
6
2. 2 layers 13mm Plasterboard 3. 35x90mm Timber stud wall
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4. 230mm Precast concrete panel
3
7
6. 110x75mm Brick veneer
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7. 2mm Metal flashing
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8. 10x5mm Silicon
10 11
5
12 14
5. 10mm Mortar bed joint
9. 5mm Frosted plastic sheet 10. 200x900mm PFC steel beam 11. 10x15mm Silicon 12. 2mm Metal flashing 13,14. Not shown on original Oval Pavilion Redevelopment Plan, 2mm metal wall ties.
The detail shown here is a part of the flooring system of Oval Pavilion’s Plant Room.
Location of the detail on the plan of Oval Pavilion redevelopement
Interrogation of the detailing decisions: Insulation - Insulation can assist with weatherproofing and eliminate moisture problems such as condensation. The type of insulation used in construction of Oval Pavilion also has soundproofing quality. Flashing and weep holes - This section of the building uses a cavity wall system, which requires an internal drainage(cavity flashing and weep holes) in order to remove any moisture that penetrates the cladding. Flashing is a thin continious sheet of metal which is installed to prevent the passage of water into a structure from an angle or a joint. Water caught along the flashing is diverted to the weepholes in the masonry facade wall which is mote suceptible to water penetration. The weep holes simply are open purpens in the brickwork. In this detail flashing is extremely important. It prevents water penetration into the lighting strip mounted in the PFC. Sealant(silicon) - Functions to neutralise one of the four predominal forces - air pressure. It ensures that the water droplets are not sucked into the building through the change in air pressure and hence ensures the internal cavity remains dry. Mortar joints - These joints are less water resistant than other joint designs(iron joint for example) as it incorporates ledges where water droplets can accumulate. Thus, to decrease water penetration, the mortar can be further compacted to reduce roughness and inconsistencies of its edges.
Sustainability and environmental analysis: The materials used in construction of Oval Pavilion( cocrete, steel and timber) contain fairly high ambodied energy. If the timber is sourced from a plantation or is recycled it will assist in the sustainability of the building. Locally sourced timber and steel will also reduce the carbon footprint of the materials as it would decrease transport energy and cost. Furthermore, if the rainwater collected from cavity flashing system can be recycled and reused within the building, it will dramatically the environmental impact and the economic cost of mainaining the building. Mortar joints also have negative environmental impact as the mortar smeared on the recesses of the bricks are cleaned with a highly acidic solution. Furthermore, mainaining and cleaning the masonry wall can also involve processes which can have a negative environmental or health impact. For example, when using highly acidic or alkaine solutions or organic solvents(which toxic fumes can cause skin burns)
Where and why things go wrong: At the masonry facade - Water flows into the cavity through the gaps between the mortar and the bricks due to bond separations, minute cracks and voids. Furthermore, absorption also occurs through the bricks and mortar, which can cause water intrusions within the building. This will cause the weakening of other structural members and materials.
References: Building Diagnostics Group 2013, Building Diagnostics Group, Atlanta, viewed 25th September 2013, < http://www. bdg-usa.com/masonry-wall-drainage-testing.html> Ching F., 2008, Building Construction Illustrated, 4th edition, John Wiley & Sons Inc., Hoboken, New Jersey. Fitzgerald J, 2010, Home Improvement Pages, Australia, viewed 25th September 2013, < http://www.homeimprovementpages.com.au/article/What_is_a_Fascia_Gutter> Heritage Victoria 2001, Department of Planning and Community Development, Victoria, viewed 25th September 2013, < http://www.dpcd.vic.gov.au/__data/assets/pdf_file/0020/36830/CleanMasonry.pdf> Krogstad N, 2007, Hanley Wood Media, Washington DC, viewed 25th September 2013, < http://www.masonryconstruction.com/audiovisual-equipment/raked-mortar-joints.aspx> McGee C., Mosher M., Insulation, Your home technical manual, Commonwealth of Australia, 2010, viewed October 2013, < http://www.yourhome.gov.au/technical/fs47.html> Wrimco Waterproofing n.d., Wrimco Waterproofing, New South Wales, viewed 25th September 2013, < http://www. wrimcowaterproofing.com.au/index.php?p=1_40>