A heliport is formed by the assembly of a planar member including longitudinally-extending deck materials, each of which has a longitudinally-extending T-slot formed in the upper side thereof and is connected to a plurality of deck slats. Each deck slat is of generally I-beam configuration, with the lower flange thereof having a plurality of longitudinally-extending striations. A plurality of fixture blocks is provided, with each fixture block having a hole therein and including a plurality of striations for cooperatively engaging the striations in the lower flange of a deck slat. The head of a carriage bolt is disposed in the T-slot of the longitudinal deck materials, and extends through the fixture block, and is connected at its opposite end to a deck slat by a washer and nut, thereby providing a rigid interconnection between the deck slats and the planar member.