Roof panel joint

A joint between adjacent roof panels of the type including spaced-apart outer and inner skins and an insulating core which secures the outer skin in shear-transferring relation to the inner skin, said joint comprising generally tubular inner and outer ribs presented along first and second upper edges of upstanding sidewalls which are formed along adjacent longitudinal edges of the outer skins, said inner rib comprising a segment of a cylinder and having a lengthwise opening between a terminal flange of said inner rib and the first upper edge of the sidewall, said outer rib having an inturned terminal strip which is engaged around said terminal edge and extends into the interior of said inner rib to securely lock said outer rib to said inner rib, said outer rib initially comprising an arcuate open loop having an elliptical transverse profile including said in-turned terminal strip whereby said open loop experiences minimal bending stresses as it is bent about said inner rib to form said outer rib;

• and a sealant engaging the inner and outer ribs to provide a primary weathertight seal at the exposed surface of said adjacent roof panels.