<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I agree with Phil's always excellent posts, except for the quote below.<div><br></div><div><blockquote type="cite"><div><div><div><div>On Oct 21, 2010, at 9:29 PM, Phil Undercuffler wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><span class="Apple-style-span" style="font-family: arial, helvetica, sans-serif; "> risk splitting the top chord of the beam. If you split that, I would immediately stop what you're doing and consult with the I-beam manufacturer. Big liability moment there.</span></div><div><font class="Apple-style-span" face="arial, helvetica, sans-serif"><br></font></div></blockquote></div></div></div></blockquote></div><div><br><div>Damaging the bottom chord would be a different matter, but once the roof decking is attached to the top chord, it serves to distribute the compressive loads along with the top chord.</div><div>Basically the roof decking acts as a huge top chord for the I beam, and therefore any point loading problems caused by lag or nail damage, are distributed around the spot by the decking.</div><div>I agree you don't want a design that depends on this principle alone, on the other hand, its not like the place is about to fall down. </div><div>I definitely wouldn't go as far as to call it a "Big liability moment". Think about your average roofing crew with a big air nailer, attaching the decking. They damage the top chord all the time, but its engineered into the design to handle that damage. </div><div><br></div><div><div><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>R. Walters</div><div><a href="mailto:ray@solarray.com">ray@solarray.com</a></div><div>Solar Engineer</div><div><span class="Apple-style-span" style="font-size: medium;"><br></span></div></span></div></div></div></body></html>