millimetres or 50x100 millimetres. However, the wall insulation may be the major factor in stud dimensions and wall thickness. Studs are arranged in multiples at corners and partitions intersections to allow rigid attachment of the sheathing( OSB) in the both sides of framing, the exterior and interior wall finish materials( Figure 1). This arrangement of studs also contributes to the wall resistance to lateral loads( Freitas and Crasto 2012).
Figure 1: Wall framing at intersecting partitions. Source: adapted from American Wood Council, 2001
Exterior finishes include a wide variety of cladding materials: wood or vinyl siding and ceramic tiles or painting applied over the cementitious board. The last variety is the most used one in Brazil due to its similar appearance to the finishing of traditional building systems. In this case, cracking in the exterior finishing can be prevented by using sealed joints between the cementitious boards. Omitted( invisible) joints can also be used in accordance with the procedures recommended by the cementitious boards’ supplier. Regardless of the exterior finishing adopted, the use of a water repellent membrane is mandatory between the OSB and the exterior finish in order to assure the insulation and the durability of the OSB. In Brazil, the gypsum board( drywall) is the most common interior finish in this building system. In addition to providing a smooth, paintable surface, the gypsum board can assure a good performance in terms of fire resistance to lightweight structural framing( Canada Mortgage and Housing Corporation 2014). A harder of adequate size is required at window or door openings to carry vertical loads across the opening. Headers may be supported by double studs or, where the span does not exceed 90 centimetres, framing anchors may be used with single supporting stud( Figure 2). Where the opening width exceeds 180 centimetres, triple studs are used with each end of the header bearing on two studs( AWC 2001).
336 ZEMCH 2015 | International Conference | Bari- Lecce, Italy