Week 9 journal

Constructing Journal Week 9

Interrogation of the detailing decisions and purpose: The roof of the Queen’s College extension is a flat roof. Therefore, a concrete parapet is built on the edge of the roof which is an extension of the wall. It helps in avoiding water from entering the house. Moreover, there is the flashing right on top of the parapet to the gutter. The use of the flashing is also to block the water from entering the house. The furring channels are for the connection between the rafters and ceiling or the metal roof sheeting

Identification of waterproofing elements: The flashing, a thin layer of waterproofing material laying on the parapet and covering the edge and the joints between the wall and the roof.

Economic implications of decisions: The cost of construction and the materials used. The costs of timber, concrete and metal are cheap and they can be easily constructed. Also, the flat roofing of the building is easy to install.

Sustainability and environmental analysis: As it can see at the Queen’s College, it is mainly constructed of concrete, timber and metal. All the carbon footprint of the three materials are low especially timber. The embodied energy of both concrete and timber are relatively low except for metal.

Furthermore, all of the main materials used can be recycled. As a conclusion, the building is probably sustainable.

Pros and Cons: The parapet and the flashing is generally use with the flat roof since they are good in prohibiting the permeation of water into the building. The box gutter and the down pipe conduce in drainage. However, the cons of the flat roof are it has to be built with stronger materials which could bear the larger live loads especially for the rain/ water loads. Besides, the flat roofing have to be maintained more compare with the pitched roof as the water cannot be run away naturally. Debris and clogged drainage system would greatly affect the lifespan of the roof. In addition, all parts of the flat roof is exposed to the sun all day long, as a result, it absorbs all the heat. The absorbed hear might be good in winter to keep the building warm but oppositely it increase the need and the cost for air conditioning in summer (Jennifer Blair 2013).

Where and why things go wrong: The use of flat roofing is more trended to leaking since the water cannot be filtered naturally unlike the pitched roof.

Referencing: Jennifer Blair, 2013, Flat Roof Pros & Cons, viewed on 8 th October , 2013, from http://www.ehow.com/info_8355787_flat-roof-pros-cons.html