Patent ID: 8627628

Claim:
A system, comprising: a thermal block arrangement over each of an opposing pair of purlins; a vapor-barrier member spanning between and secured over opposing pairs of purlins, the vapor-barrier member extending between each thermal block arrangement having engaging surfaces that hold the vapor-barrier member over the head of each purlin such that the vapor-barrier member spans between each purlin at a level below each purlin head; an insulation receiving cavity defined by an upper surface of the vapor-barrier member and between opposing faces of each of the thermal block arrangements, the cavity being substantially rectangular in cross section; wherein the engaging surfaces of the thermal block arrangement include: an inside vertical wall which presses the vapor-barrier member against an upper portion of a web of the purlin; a horizontal ceiling which presses the vapor-barrier member down on a flat top of the purlin; and an outwardly angled wall extending from said horizontal ceiling and away from said inside vertical wall holding the vapor-barrier member down, over, and below a front lip of the purlin.