On a pitched roof, my understanding is that the rubber underlayment should go down first, then the drip edge. I'd have thought that the drip should go first: then, any water captured by the membrane would run off over the drip. I can guess that putting the membrane first lets the it seal the drip nails. But, to what end, if there's no place for the water to go?
Can anyone shed any light on this?
Thanks