<div>From my experience in the commercial construction trades which was hanging steel plumbing pipes from this stuff, you can hang from the top cord only. Use a clamp that is threaded for allthread rod. Don't drill the cords. Drop the allthread below the bottom cord and attach the cross/roller beam. No problem </div> <div> </div> <div>The hambro system is rated to hold the weight of the materials plus some people standing on it, AT LEAST!. A roof structure will hold less weight than a floor structure. The roof is not designed to carry any extra unless there is a rainwater load possibility. The more joists you spread the load across will ensure safety. </div> <div>Try this:</div> <div>First hook a clamp to the top cord of one joist and hang your lift. Put some straps around a 1902 upright and start to lift. Measure the deflection with a story pole and tape measure. If you feel safe lifting it all the way, when you distribute the load, you have a safety factor. <br>Trial and error. Wear your hard hat or the insurance won't cover you after you've been squashed.</div> <div> </div> <div>Keith Roberts<br> </div> <div><span class="gmail_quote">On 4/26/07, <b class="gmail_sendername">Phil Bondi</b> <<a href="mailto:phil@philbondi.com">phil@philbondi.com</a>> wrote:</span> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Hi all.<br><br>Before I spend any money on this, I want to get your<br>thoughts on this subject..<br><br></blockquote> </div>