Environmental Impacts of Multi-Storey Buildings Using Different ...

- 89 -7.1.1 Platform and Balloon ConstructionTwo main types of construction method exist for the erection of light timber buildings. Thesemethods can also be used for the erection of a post and beam structure (Buchanan, 2007) suchas the post tensioned LVL system. The first of these methods is platform construction, shownin Figure 7.2a in which the building is constructed on a floor by floor bases. This mean thecolumn and wall segments will by one single storey high. This method has the advantage ofproviding a consistent working platform from the floor below. In the construction of lighttimber frame buildings, this method is not recommended for buildings above four storeys ascrushing due to perpendicular-to-grain loading will become a problem. The second method isthat of balloon construction, as shown in Figure 7.2b, where the columns and walls arecontinuous over several storeys and beams and flooring are then attached up the height, withthe erection of three floors occurring without the additional placing of vertical members. Thismethod can save construction time due to less members being assembled on site. Theprefabrication of members, added to the lightness of timber, means that the balloonconstruction method is preferred for post- tensioned timber construction.a)b)Figure 7.2: a) Platform construction method b) Balloon construction method7.1.2 Assembly of Key ComponentsThere are a number of key components/technologies identified with the construction of theTimber buildings which contribute to the ‘constructability’ of the designs. Current research atthe Department of Civil and Natural Resource Engineering at the University of Canterburyincludes;