Need help with truss bracing

[ldwain]

Thanks for the link. Don't all truss manufacturers provide you with the bracing requirements for their trusses? When I built my shop the building inspector wanted the engineering certificate from the truss manufacturer along the bracing sheet. The bracing sheet listed all required braces including lumber grade and size along with the number of nails, size of nails and where each nail had to be placed in the braces. It left no room for errors.

No, typically bracing plans are outside the scope of the truss manufacture's design. The bracing shown on the truss design drawings is restraint of individual truss members (webs) that need to be braced to prevent buckling to due forces in the web members themselves. Bracing for loads not in the plane of the truss is typically not shown and is the building designer's responsibility since design of the rest of the building needs to be considered in order to properly transfer the loads to the foundation. Since many post frame structures do not involve a building designer, the BSCI documents can be used for guidance for the truss restraints. While some manufacturer's may provide this design as a service, most do not. As an example, ALL truss systems need diagonal bracing installed, this is not typically shown in the truss package, except in the BCSI documents delivered with the trusses. The exception to this would be if you purchased an engineered building package. In that case, the manufacturer of the building may have provided a building bracing plan that includes truss bracing. The bracing specified on the individual truss design drawing would still need to be installed to prevent in-plane buckling of the truss members.

 

[ThomasH]

To add just a bit to the previous discussion, truss bracing is typically specified depending on the expected wind load in the area for the building, so it varies in different parts of the country. Typical truss bracing is scissor bracing, although other may be required depending on the wind load and length of the truss. Scissor bracing is typically applied to the horizontal middle truss member, in a scissor fashion to take the thrust load of the hip of the roof and diagonally brace that to the bottom truss or wall header.

 

[crbr]

Thanks for the pictures.

 

[BX25HD]

Well I got all of the trusses up yesterday and pot all of the purlins on. I rented a 16' ladder to put on the purlins and the bracing. I'm glad that job is done!