Abstract: A roof drain including a grated, inverted, frusto-conically-shaped cover received in a roofing material clamp having a radial, upstanding, debris-discouraging flange. The cover and roof material clamp are demountably fixed to a flanged drain body and clampingly maintain roof material therebetween. The drain body is received by a flanged sleeve. The drain body and sleeve flanges clampingly maintain roof substrate therebetween by means of a nut threadingly interengaged with threads on the drain body which urges the sleeve toward the roof substrate.