Wind Uplift On Roof Joists

The steel joist institute discusses the key points of technical digest no.

Wind uplift on roof joists.

Wind uplift design for trus joist tji roof joists in many commercial buildings wind loading may result in uplift loads on roof rafters. The technical bulletin below explains the design considerations such as bottom flange bracing and uplift connections at bearing. Roof trusses can be found in the commentary for asce 7 as examples of both mwfrs and c c. 6 design of steel joist roofs to resist uplift loads.

New uplift loads can induce stress reversals in tji roof joists as well as uplift reactions at bearing locations. The customary truss to bearing connection of three toenails may not develop enough resistance for the calculated uplift reaction. By providing a complete load diagram to the manufacturer. See the sji code of standard practice for additional information.

Topics for discussion design responsibility what is a standard joist. Tb 125 wind uplift design for trus joist tji roof joists. Tb 813 trus joist tji joist residential bonus room span tables. Tb 310 use of topical coatings with weyerhaeuser engineered wood products.

Under typical gravity loading a joist experiences compression stress in the top flange. How should seismic and wind loads be specified. Assumptions dimensions designations joist design for wind uplift properly specifying uplift joist design by manufacturer for. Also receives wind load directly from the roof sheathing i e cladding and therefore acts as a component which puts the truss into the c c category.

Topics include the design requirements of the asce sei 7 10 wind provisions for open web steel joists and joist girders and the end anchorage and bridging considerations for uplift loads on steel joists. Uplift bridging is required whenever the bottom chord goes into compression. In order for a structure to be sound and secure the foundation roof and walls must be strong and wind resistant. Tb 827 wall tension tie connectors for tji joists.

Design of steel joists and roof decks michael r. Tb 824 trus joist tji joists in ceiling applications. When building a structure it is important to calculate wind load to ensure that the structure can withstand high winds especially if the building is located in an area known for inclement weather. This will be true if there are net concentrated up loads.

When is uplift bridging needed. Uplift reactions can occur with gravity loads on multiple bearing trusses or with high wind conditions.