Abstract: A roof drain for draining rainwater from a roof. A bell-like strainer is supported by a compression/tension unit including resilient means, which unit is in turn mounted to a drainage sleeve that communicates with a leader. The strainer is secured to the drainage sleeve by a threaded bolt that passes through bores in the strainer and the compression/tension unit, and engages a nut received by the resilient means. Tightening the bolt moves the strainer downwardly into a substantially watertight fit with roofing membrane interposed between a skirt of the strainer and a collar on the drainage sleeve. The resilient means, which may be resilient material, a spring or the like, provides continuous tension between the strainer and the drainage sleeve.

Abstract: A washer assembly combination for use with a threaded fastener which combination includes a rigid cup and a resilient member received within the cup. The resilient member, typically a polymer of ethylene propylene diene monomer, is oversized with respect to the cup interior such that, in use, the member is compressed so as to exert a compressive force on materials held together by the fastener. The assembly is useful for fastening together of sheet metal materials, and particularly, provides a system for sealing against the ingress of water between two layers of material in which such an assembled combination is used in conjunction with a clamping member.