I realize no one can answer these questions for me with out knowing the project but thought some contractor on here might have some opinions on when it’s worth it for savings. TJIs or 2xs at floor joists? Is the savings in 2x worth it to have plum TJIs? Lightweight timber roof frames can be constructed to suit any shape (simple or complex) using either individual timber elements (stick-built) or trusses and can be used under metal sheeting or tiles. Specific questions I have:Ĭan I space all walls floor joists and trusses 24” o.c? Roofs can be of many different shapes including hip, gable, skillion or flat. I was going to get my engineering through the lumber yard but I bought myself some extra time so I’m thinking now I might engage with a structural engineer to value engineer my framing plans and foundation plans. Our next step is to check if this deflection is less than the allowable deflection for our given beam span. The mass of rafters and underpurlins is accommodated in. For guidance on roof and ceiling mass refer to Appendix B, AS1684.2. Notes i) Maximum spans are based on the support of roof mass only up to a maximum sheet roof mass of 20 kg/m2 and tiled roof mass of 60 kg/m2. 16 Lintel span Ceiling Joists B Rafters A Strutting Beam (or Girder Truss) Hanging Beam Lintel to. Fasteners for H LVL ô shown in these tables, and installed in accordance with the. Engineered Wood Products Australia // Span Tables // Strutting Beams. The top flange of the Lintel is assumed to be laterally supported at mid-span. In this case the hanging beam will be a combined strutting/hanging beam (7.2. The hanging beam could also be used to provide support for the roof load. If the span is excessive then counter beams (7.2.6, 7.3.7 Figure 7.2 & 7.21) will provide support for the hanging beams. The Strutting Beam is assumed to be supported by the Lintel at mid-span. That requires an underpurlin size of 2/140x45 (Table 28, RLW2078mm. Is there a cost saving to using standard 2x lumber instead of TJIs and LVLs? Structure design is: The length of the rafters are assumed to be within 15 of the Strutting Beam span (B).