Beams with constant 'L' andinverted 'T'cross-section are made of pre-stressed reinforced concrete and have a smooth formwork surface. Combined with 'Pigreco' and 'honeycomb' type floor panels, they are suitable for flat roof and intermediate deck structures. The production range, which varies according to the spans and overloads applied, includes numerous types distinguishable by different heights, total and bottom sole. The behaviour in the presence of fire is excellent, with resistances up to a maximum of R 180'.