Abstract: A roof, or a portion of a roof, resiliently securable to a sub-structure (4) of a building, the roof or roof portion comprising:a panel (1);a strip (2) which is overlapped by and supports the panel (1) on at least a portion of the edge regions (3) thereof; andan intermediate layer (10) of a resilient sealing material which spaces the panel (1) from the strip (2) such that the panel (1) is capable of relative movement with respect to the strip (2) while sealing the panel (1) with respect to the strip (2).A method of providing a building with such a roof is also disclosed.