I notice that the clamp sometimes tilts sideways on a lap rib depending on the roof overlap design. I have also seen one roof profile where all the ribs top trapezoid sections are asymmetric so you can't avoid a clamp tilt. If a clamp is placed on a lap and then tilts, this will create extra pullout stress when it is twisted straight to align with the rails, especially when on a purlin. I have also seen some engineers instructions requiring the placing of clamps over purlins, however they made no mention of placing on a lap. It is hard to get a definitive answer for my roof as nobody can identify it.
Great video - We get a heap of queries around roof profiles - Thanks for the review Dane!
Are they installed on the lap rib or should I avoid the lap rib.
I notice that the clamp sometimes tilts sideways on a lap rib depending on the roof overlap design.
I have also seen one roof profile where all the ribs top trapezoid sections are asymmetric so you can't avoid a clamp tilt.
If a clamp is placed on a lap and then tilts, this will create extra pullout stress when it is twisted straight to align with the rails, especially when on a purlin.
I have also seen some engineers instructions requiring the placing of clamps over purlins, however they made no mention of placing on a lap.
It is hard to get a definitive answer for my roof as nobody can identify it.
Instructions unclear