Friday, January 14, 2011
What an interesting week. I have spent the last three days out of the office in full long-john gear, two pairs of socks and gloves and a boggin. For the last two days I climbed into, through, and around 20 attics. Most of the projects we see are under construction. I learned a lot of things the last two days by observing roof trusses and framing that have been in place over a decade. Particularly, I learned the importance of proper truss member bracing. As shown in the picture, weak axis bending is a limiting factor in truss design. The truss manufacturer relies on the installation of bracing to prevent this mode of failure. When the bracing is not installed, the web members are overstressed and, as shown, can fail.