Timber Use in Truss Structures for Roof (“Howe” Type – 8 to 18 Meters)

Abstract

The wood is a material widely used for several purposes, especially in the construction industry. There are many factors that this is due, between them the versatility and abundant availability of the material. However, the intensive use of some species might cause shortages. The lack of information about the wood behavior when it is exposed to various conditions, as well as projects not supported by regulatory rules, may imply in its inappropriate use, compromising in the safety of the structure. In this context, it was proposed the elaboration of roofing structures projects with the following characteristics: lattice type buildings "Howe" (10° slope -cement tile); span of 8, 10, 12, 14, 16 and 18 meters (geometrical proportion, in design, surrounding a 1: 3); typology of the lateral side of the building openings -relations 1:1, 2:1, 6:1 and open (coverage of small dimensions' support) preservative treatment. Then, was determined the ratio of the wood amount (m³) and the built area (in design) to woods of C20 and C30 classes, following the requirements of NBR 7190: 1997. Front of the analysis of results was evidenced that it is possible to use unconventional woods applied in triangle framework structure in big spans, obeying a well elaborated conception of project.

Using Alternative Timber in Parallel Flanges Truss Structures for Steel Roof - Slope 20º, with Spans between 16 to 26 Meters

“…Analyzing all openings and spans ratios, the volumetric timber consumption ranged from 0,0075 to 0,0134 m³/m². According to Palludo et al [9], the timber consumption per constructed area ratio for rectangular sheds is about 0,020 to 0,030 m³/m², evidencing that the results presented in this research proved to be efficient and satisfactory.…”

“…In general, the opening ratio 1:1 presented the highest timber saving for most spans, except for the 20m span. When it is compared to the results from the study performed by Palludo et al [9] with 8 to 18m spans in triangular trusses, it is also possible to verify that the opening ratio 1:1 represents the best option in all cases.…”

Properties of Eucalyptus umbra Wood for Timber Structures

“…For wood use as structural element in construction of bridges [7], trusses [8] among others [9], physical and mechanical properties are the most important [10][11][12].…”

Technical Feasibility Study for the Use of Alternative Timber in Latticework for Roofing with Spans between 16 and 26 Meters

“…However, with the passage of time and the rapid development of technology, new building materials have been emerging, such as concrete and steel, and there is also a certain bias with wooden structures [2]. This is due to the lack of awareness of owners and builders, who prefer to hire only the cheapest labor and with some practical experience, but without technical knowledge, causing a great waste of wood and constructions designed with empiricism, in which they were subject to the appearance of pathologies and excessive deformations [3].…”