Abstract: A solar heat collector is described comprising, in combination, a plurality of fluid conduits and a mat formed of intersecting ribs and posts that provide a support surface as for a decking. One end of each post projects downward and below the intersecting ribs to form open channels between posts. The fluid conduits extend beneath the mat and are located in the channels. Each fluid conduit connects with a pair of headers which extend along opposite sides of the mat, and a pump circulates water taken from a reservoir, such as a swimming pool.