Double-wall chimneys - Specific technical features

Details of a double-wall chimneys
The bearing shell is kept ventilated by an air gap between the mineral wool and outer wall. Insulation by mineral wall prevents any acidic condensation. The wool is wired to ensure mechanical resistance all the way up the chimney

External flanged joint
The flanged joint connects the two elements to the bearing shell. It is essential to guarantee the long life of the structure. Depending on the diameters, stress and thicknesses, the flange is reinforced by gussets and belts, which prevent punching. The flanged joints on double-wall chimneys can be external. They are painted for protection. Internal flanges can be provided if required for aesthetical purposes.