GoBizon
Structural
- Nov 7, 2006
- 12
Original Design, all wood members, 72’ roof span (6:12 slope): 20’ monoslope truss from brg wall to girder truss, 32’ gable truss girder to girder, 20’ monoslope truss from girder to brg wall. Girder truss designs have been verified and total span is 80’. The 72’x80’ area is clear spanned in both directions with the exception of steel columns at girder supports.
Problem: Owner does not want a ‘dry’ sprinkler system.
Arch. Solution: Change insulation of roof trusses to an insulated panel atop the typical roof sheathing. However, the cost is too great for this over the entire roof area. Therefore, replace the 20’ monoslope trusses with TJIs and provide a continuous vent space at the intersection of TJI and roof truss. This creates 3 continuous ‘slots’ in the roof diaphragm: the ridge and one 20’ up the slope at each end. The wind load parallel to the trusses is 255plf at the eave.
Question: The use of continuous ridge venting seems to be a generally accepted practice. Are there any concerns with having the 3 continuous breaks in the roof diaphragm?
Problem: Owner does not want a ‘dry’ sprinkler system.
Arch. Solution: Change insulation of roof trusses to an insulated panel atop the typical roof sheathing. However, the cost is too great for this over the entire roof area. Therefore, replace the 20’ monoslope trusses with TJIs and provide a continuous vent space at the intersection of TJI and roof truss. This creates 3 continuous ‘slots’ in the roof diaphragm: the ridge and one 20’ up the slope at each end. The wind load parallel to the trusses is 255plf at the eave.
Question: The use of continuous ridge venting seems to be a generally accepted practice. Are there any concerns with having the 3 continuous breaks in the roof diaphragm?
