Learning summary Pitch and sloping Roofs:
Roofs: -
part of the enclosure system (shields structure from weather, moisture and heat) can be flat, steep gable, gable, tiled, or combination roofs can be exposed or hidden behind parapet walls
Roof Systems
Flat roofs: Pitch 1-3° -
Week 6
pitch is never completely flat to drain the water off the roof and down drainage systems if the pitch was 0° water would pond on top of the roof increasing the load on the structure which would result in damages such as leaking waterproofing is very important with these roofs
Some types of flat roofs include:
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Pitch > 3° Sloping roofs (skillion, sawtooth) structural frame consists of beams and purlins Pitched roofs (gable, hip) can be made up of rafters, beams and purlins or trusses
Some types include: Skillion roofs: similar to a flat roof but is put at a higher pitch for better drainage (Build, 2014)
Roofing lining material considerations -
the biggest consideration for roofing is how to prevent water and moisture getting into the building and making sure that the cladding is impervious
Tiles: -
need to be at a greater slope then metal roofing with at least a 15° angle so that they can overlap each other and prevent water from getting in between and through the tiles which causes leakages
Sawtooth roof: which resembles a series of skillion roofs (becoming more popular in residential homes for its sustainability of letting natural light in and controlling temperatures (Build, 2014))
Concrete slab
Gable Roofs: allow for additional room for attics or Flat trusses
higher roofs, light framed triangular roof
Sheet metal: -
roughly has an angle of 5°
Concrete: Beams and decking
Hip roofs generally have large shady eaves and are recognised by the vertical, triangular section (corner) of the walls connecting to one or both end of the roof (Newton, 2014)
Joists and decking/roof sheet
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Use concrete roofs when the area needs to be trafficable, used as car parks, needs a good fire rating or simply for aesthetics More expensive type of roof Needs a membrane layer to become waterproof
Glossary and References
Week 6
Glossary
Outriggers: Frequently used when overhang exceeds
References
12inches on gable roofs (Hurricane Retrofit Guide, n.d.). Provides additional stability against forces such as wind.
Build. (2014). Roof Designs and Styles. Retrieved from http://www.build.com.au/roof-designs-and-styles Newton, C. (2014, April 9). W06_c1 Roof Systems. Retrieved from http://www.youtube.com/watch?v=q5ms8vmhs50&fea ture=youtu.be Hurricane Retrofit Guide. (n.d.). Gable End Overhangs. Retrieved from http://www.floridadisaster.org/hrg/content/roofs/over hangs.asp
Purlins: a horizontal member used in a roofs to support the roof decking and rafters which is then supported by the struts and structural walls. Usually Z, or channel shaped (Carpentry for Vocational schools, n.d).
Parapet: A wall that encloses a roof (usually a flat roof)
Carpentry for Vocational schools. (n.d.). 13.2 Technical Terms of a Roof. Retrieved from http://collections.infocollections.org/ukedu/uk/d/Jgtz0 06e/14.2.html