Roof fan and opening waterproof mounting structure

The invention mainly discloses a roof fan and opening waterproof mounting structure. A fan bracket is arranged at the opening which is arranged according to a fan loading bracket purline of the roof; four edges of the fan bracket are bonded with sealing adhesive tapes; a heat insulation cotton is laid at the peripheral edge of the fan bracket; the bottom of the heat insulation cotton is supported by a steel wire net support; a roof board covers the heat insulation cotton and bonded with the sealing adhesive tapes; and the roof board is also fixedly connected with the fan bracket via a roof tightening piece in a secondary way. According to the invention, in combination with the characteristics of the roof system board type and the requirements on the roof water exhaustion, the tightness of the roof is guaranteed and the rainwater intrusion is effectively prevented so that the integral roof system reaches the same waterproof effect with the roof panel while the integral bearing force is not reduced.