This puts the collar tie in compression and increases the tension force in the rafter tie (the moment arm between the compression and tension forces in the collar and tie, respectively, decreases). However, when you add collar ties, you are introducing a lower point where the rafters can react against each other, like they do at the ridge. Common rule-of-thumb practice is to locate the collar ties in the top third of the rafters. Their intended purpose is primarily to prevent roofs from splitting at the ridge in the event of large uplift forces as the connection to the ridge is traditionally tenuous (end and/or toe-nails). I'm not a layman, so let's get it on! :)Ĭollar ties are common in residential roof construction.
The thread has since been removed (layman question i suspect).
I posted an unpopular fact in a thread the other day that i was hoping we could discuss a little more. Shall be given without reservation for the public good.Īnd in fidelity to my profession, I shall give the utmost. Practical use the principles of science and Has been spurred by the engineering genius.
