Abstract: A load-bearing building panel capable of forming an external wall cladding or roof component has a solar heat collecting capacity in the form of channels for heat exchange fluid incorporated in the fabric of the panel. The panel is made of a structural plastics material, such as G.R.P. laminate, successive layers being moulded to simulate tiles. On the back or underside, longitudinal reinforcing beams are built in during laying up of the panel. Between the beams cores or formers defining a matrix or channels are encapsulated in layers of the G.R.P. Wax cores are melted or dissolved out after curing of the panel; metal formers remain embedded in the fabric of the panel. The matrix is connected by flow and return pipes to a heat exchange system within the building. Panels intended for roofing have ridge flanges and wall plates moulded into the substrate at the appropriate pitch angle, and a split capping tube embraces the ridge flanges. A pitched roof formed by oppositely sloping panels is self-supporting.

Abstract: A G.R.P. roofing panel is stiffened by longitudinal beams on its underside and is designed to span one pitch of a pitched roof from eaves to ridge. It has an outer skin and an inner impervious liner spaced therefrom and supported on the stiffening beams so as to form a tunnel open at both ends and extending from the vicinity of the eaves to the line of the roof ridge, where vents to atmosphere are provided in the outer skin. Air is convected upwards through the tunnel due to the heating of the outer skin by radiation from the sun, and a damper controls this flow of air. It can be arranged to operate differentially on air flowing in from outside the building and air flowing in from the roof space through a port in the liner. At the line of the ridge the liner meets and is sealed to the corresponding liner of a counterpart panel on the opposite pitch of the roof so as to maintain the integrity of the convection air circuit in each section of the roof.