A roof panel system assembled from roof panels comprising a panel portion bounded along a support edge by a support element and along an opposed cover edge by a cover element. The cover element adapted to rest upon and provide resilient sealing and locking engagement with the support element of an adjacent panel. The support element adapted to provide resilient support and locking engagement with the cover element of a second adjacent panel. In an embodiment a panel cover is provided for shielding an upper surface of the panel portion and adapted to inter-fit and lock with engaged support element and cover element pairs along the support element and the cover element of the panel when the panel is engaged with adjacent panels when assembled. In an embodiment contoured insulated panels are provided as a base to support the panels. The contours providing passageways to allow the transport of air beneath the panels when assembled.