Rayleigh Windmill is a six-storey tower mill with a Kentish cap winded by a six-bladed fantail. The mill had two single Spring sails and two Common sails carried on a cast-iron windshaft. The tower has no batter until second-floor level, where the stage is. The tower is diameter at base level and internal diameter at the curb. The brickwork is thick at base level and at curb level it is thickened out to . The mill is high to the top of the cap. The mill drove three pairs of millstones.
