Flamebar BW18 fire resisting ductwork system is manufactured in sections and assembled on site utilising analyzed fireproof gaskets/sealants. Smoke leakage (S): The duct shall not Possess a leakage exceeding 5 m³/h for each one m² of inner area region. This shall be relevant to the area region with the duct https://ductworth-installation88900.laowaiblog.com/35468381/a-review-of-ductworth-installation