Void tubes are supplied as a spiral lockseam duct with an internal seam providing a smooth external surface for ease of handling with easily fixed ends in a flat or bullnose shape as required. Corrugation profiles are applied to prevent tube collapse or deformation while permitting the use of minimum gauge material and thereby offering savings in material cost and the overall weight of the concrete structure. Longer, unsupported spans can be achieved using void tubes through their ability to offer up to a 40 percent reduction in concrete weight which favourably affects the ground work, framing and reinforcements. Void tubes are made standard from galvabond material and have an extraordinary weight to strength ratio due to the strong corrugation profiles and are supplied in diameters up to 1500mm in any transportable length.
