Patent ID: 6367212
Filing Date: 2002-04-09
Classification: E04B

Abstract:
A fire-retardant roof construction provided in a building wherein a fire-retardant wall (2) separates a first room (3) from a second room (4) and supports purlins which carry a roof cladding (26), the fire retardant roof construction being characterized in that it comprises a first set of parallel purlins (7a) extending over said first room (3);a first set of upright cleats (6) secured to the top of said wall (2), each of said first set of purlins (7a) having an end pivotally mounted to a corresponding one of said first set of upright cleats (6) about a horizontal axis parallel to said wall adjacent the top of said wall; a second set of parallel purlins (7b) extended over said second room (4); a second set of upright cleats (6) secured to the top of said wall (2), each of said second set of purlins (7b) having an end pivotally mounted to a corresponding one of said second set of upright cleats (6) about a horizontal axis parallel to said wall adjacent the top of said wall; the pivotal mountings being so located that each purlin (7a, 7b) can collapse to hang down from its pivot (9) without structural damage to the wall (2) or the respective cleat (6); a first respective fireproof curtain (18) sealing the walltop space between each adjacent pair of purlins (7a) of the first set; a second respective fireproof curtain (21) sealing the walltop space between each adjacent pair of purlins (7b) of the second set; the two curtains (18, 21) defining between them a sufficient space (16) so that damage to one said curtain (18, 21) from collapsing purlins does not entail any breach of the other curtain; and a divide (27) in the roof cladding directly over said space, for controlled separation whereby the cladding (26) can collapse together with its supporting purlins over one of said room (3, 4) without effect on the purlins, or on the cladding supported by the purlins, of the other of said rooms (3, 4).