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Week 6

FLIPPED CLASSROOM Roof system Roof is a primary sheltering for the enteral space of the building, collect rainwater carry away by gutter. Roof have different forms that influence the total appearance of the building. Flat roof: pitch 1째 - 3 째 below are some example of flat roof Increase the weight, the load. Result in leakage

Pitched and sloping roof: pitch larger than 3째 Concrete roof is more expensive. Can be useful when trafficable roof are require, eg. Car parks or fire ratting. A generate plat plate of reinforced. Structural steel framed roof: more common roof. Flat structural steel combination of primary and secondary roof beams with heavier roof finished such as metal deck. (Ching, 2008) (Ching, 2008)

Sloping structural steel roof consist of roof beams and purlins and lighter sheet metal roofing

Portal Frame: consist of a series of braced rigid frames (two columns and a beam) with purlins for the rood and Girts for the wall. ) (Ching 2008)

Trusses roof: frame roofs constructed from a series of open web type steel or timber element Space frames: 3D plate type structure that are long spaning in two directions. 3D trusses. Light framed roof: timber, cool-formed steel section Gable roof: vertical, triangular section of wall at one or both ends of roof

Metals Types :   

Ferrous : iron , most common and cheap Non – ferrous : all other metals – generally more expensive , less likely to react with oxygen and superior working qualities Alloy: combination of two or more metal (ferrous alloy contain iron)

Properties: varies on which metal is use.       

   

Hardness Fragility Ductility Flexibility/ plastic Porosity / permeability : use for guttering ,flashing Density: high Conductivity : good conductor of heat and electricity, can be advantage or disadvantage deepens on location and purpose Durability/ life span : can be very durable Reusability / recyclability : high Sustainability & carbon footprint : very high embodied energy Cost : generally cost effective

Considerations: React with other metals by taking / giving up on other metals’ ions

Ferrous metals Iron: Significant important Magnetic properties, very reactive chemically (easily corrodes through rusting); good compressive strength. Types & uses       

  

Wrought Iron: iron heated and hammered into the desire shape Cast iron: Iron melted and poured into mould to cool. Have very high compression. Iron alloy: steel: alloy with iron with carbon being the primary additional alloy element. Steel is a very strong material, it transfer heat and electricity, can be form into many different shapes, long lasting and resistant to wear. Farming Hot rolled: element shaped while metal is hot, generally used as primary structural element. Joints are welded or bolted Cold formed steel: element are folded from sheets that have been previous produce and cooled down. Used as secondary structure – protect be hot dip process (GALVANISATION). Joints are bolted or screwed. Reinforcing bar – good tensile resistance, steel is used in conjunction with concrete to produce reinforced concrete. Steel sheeting: cladding and roofing must be protect from weather exposure. Stainless steel alloys: chromium is the main alloying element (minimum of 12%), alloy milled into plate, bars, wire and tubing.

Non-ferrous metals and alloys Aluminium: Light compared to other metals    

non- magnetic and non –sparking easily formed, machined and cast pure aluminium is soft and lack of strength, but alloy with small amount of metal have very useful properties use: window frames or other glazed structure, cast door handles, cladding panels , pow coating

Copper: conduct electricity    

electricity wire very malleable and ductile good conductor of heat and electricity use: roofing material, natural weathering cause copper to develops a green colour patina over time/ hot and cold pipework/ electrical cabling

Zinc : use in it’s pure form 

thin layer of zinc on iron or steel known as galvanizing

Lead: less commonly use 

toxic stay in human body

Tin: rare today Titanium: 

thin, expensive ,use to cladding material

Bronze: alloy  

corrosion hard

Brass:  

handles, taps easy to work with


Key terms: Trusses: a structural that combined by several triangles. Rafter: one of a series of sloped structural member / beams that extend for the ridge or hip to the wall Eave: bottom edge of a roof Purlin: any horizontal or longitudinal structural member in roof except the roof framing. Alloy: combination of two or more metal Cantilever: a beam anchored at only one end Soffit: underside of construction element Portal frame: consist of a series of braced rigid frames (two columns and a beam) with purlins for the rood and Girts for the wall. ) Top chord: top beam in the trusses


Ching.D.K (2008 ) building construction illustrated (4th edition), John Wiley & Sons. Inc.

2014 constructing log book 6