[TheForge] Wooden Beam strength for Rigging

[Andrew Vida]

terry l. ridder wrote:
> hello;
> 
> comments below;
> 
> On Sun, 29 Jan 2006, Woolley wrote:
> 
>> Greetings,
>>
>> I seem to remember a thread about beam strength a while back but don't
>> have any info.  I'm not sure if this is the right forum but here goes.
>> I want to hang small steel I beams(6"?) under my roof joists to rig
>> from. I'm hoping to get up to 1/2 ton or so capacity.  The beams
>> measure 3x11 1/2 with no room above (obviously butt up to roof deck),
>> so I have to drill to bolt through or lag in to hang straps down and
>> under to support steel.  The joists are spaced 2 feet apart. I hope
>> to span at least 5 or 6 of them. Does anyone have a known reference
>> for engineering specs on this or any practical experience doing
>> something similiar?  Any help would be appreciated.
>>
> 
> you really do not want to do that.
> a 2 ft span between rafters is not enough support.
> also you run the risk of weakening the rafters and flexing the roof
> decking and causing the roof to leak.

	I'm with Terry on this one.  You can tie them into the vertical 
structure, just leave the roof system out of it.  Better yet, erect a 
separate load bearing structure.  I think you will be glad you did the 
extra work.