Loads

I am thinking of using wood trusses for the roofing/ceiling structural systems on some houses I shall build. I remember, though, an engineer/volunteer fireman commenting back in 1989 that the connector plates are prone to expand and pop off, early on in a fire, causing catastrophic structural failure. Was this the case, and if so, has this problem been corrected?

Do you have open web floor truss span tables available?

I am a truss manufacturer in an area of the country that often has some pretty severe winters. It concerns me how little some of the local builders seem to know about snow load design. What are some of the things that need to be considered?

Can you explain drag loads and how to calculate a drag load pertaining to roof trusses?

What are the requirements for installing valley sets over roof trusses? I am interested in nailing and support conditions. Some engineers ask for the bottom chord of the valley truss to be ripped to match the roof pitch of the underlying trusses. Is this necessary? How can I calculate values for uplift resistance for the building inspector?

ASCE/SEI 7-16 Minimum Design Loads for Buildings and Other Structures has revised Chapter 30 regarding Components & Cladding (C&C) wind loads on roofs. This report clarifies the type and scope of changes being made that will also change in the 2018 edition of the model building codes. 

The truss industry is currently employing ASCE as its source for the loading of live loads to the bottom chord of trusses for uninhabitable attics, in accordance with the International Residential Code and the International Building Code. However, there currently is a discrepancy between ASCE 7, the IBC and the IRC. This report examines the discrepancy and the correct loading for proper truss design.

The capacity of a ribbon board and its system through the composite of the ribbon board, floor sheathing and bottom plate of the wall has not been ascertained. In order to provide better guidance, a series of tests were conducted in order to determine the capacity of the ribbon board system.

“More often than  not, if it’s a flat roof, it has a green roof on it.”

 
The Industry Testing Subcommittee is making plans to keep SBCRI busy in the coming year.