Abstract: A concrete forming structure is provided wherein a pair of substantially parallel trusses have a plurality of beam members placed transversely across their upper end with a substantially planar upper deck secured to the upper edges of the beams. Each beam has an upper portion which comprises an open, inverted top hat section into which a wooden joist member may be forced and graspingly secured in snug manner. Panels, such as plywood, which are usually used for concrete forming, may be nailed or screwed to the concrete forming structure at the wooden joists engaged in the open top hat sections of the beams. The deflection resistance of a beam having a wooden joist graspingly and snugly secured therein is improved over that of an I-beam having a similar metal cross-section.