This part of ISO 834 specifies the procedures to be followed for determining the fire resistance of beams, when tested on their own. Beams are normally tested with their underside and two vertical sides fully exposed to heating. However, when the exposure is from four sides or less than three sides, appropriate exposure conditions are necessary. Beams which are part of a floor construction are tested with the floor construction as described in ISO 834-5 and are subject to evaluation of integrity and insulation. The application of this test to other untested forms of construction is acceptable when the construction complies with the direct field of application as given in this part of ISO 834 or when subjected to an extended application analysis in accordance with ISO/TR 12470. Since ISO/TR 12470 gives only general guidelines, specific extended application analyses are to be performed only by persons expert in fire-resistant constructions. General guidance on this test method is given in annex A.