Timber is part of society's evolutionary process. It presents several utilities because it is versatile and easy to apply. However, it is often extracted incorrectly from nature and used in inappropriate ways. In civil construction it is predominantly applied temporarily and, when it has structural purpose, it is used without knowledge about its properties and absence of structural projects. Thus, this research aims to assess the viability of employing not so usual species, with class resistance C-20 and C-30, in its usage as component structural element of industrial sheds with truss structures for roof (parallel flange) "Howe" type (20º inclination -steel roof tile); span 16, 18, 20, 22, 24 and 26 meters; typologies of edification lateral openings -1:1, 2:1, 6:1 and opened. Therefore, it was determined the ratio between timber volume (m³) and constructed area (m²) according to NBR 7190:1997 standards, making it possible to verify the applicability of C-20 and C-30 species to industrial sheds typology determined in this research.

The combination of hot weather typical factors, such as high temperature and low relative humidity of the air, associated with the delay in concrete application due to lack of planning in concreting, are some causes of slump loss in this material. Depending on the type of work and the adopted execution methods, this loss may make both placement and compaction more difficult. Thus, consistency correction through water addition or other plasticizer additives are common. In this context, this research aimed to analyze the variations of slump loss in concrete through time and the consequences of water addition in the mixture. Therefore, it was performed a study with trace of characteristic resistance to compression correspondent to 35 MPa, analyzing 70 test specimens in a total of seven subsequent periods, from 0 min (after preparation) and 180 min. The specimens were molded according to ABNT NBR 5738 (2015) Brazilian standard and submitted to compression test after 28 days being cured, according to ABNT NBR 5739 (2018) Brazilian standard. Results showed that after 180 min, water addition caused a 68,60% increase in water to cement ratio and a 59,20% loss of resistance to compression. In summary, water addition to slump correction was observed to be an extremely harmful practice to concrete and it should be avoided or minimized.