Whilst Lindab Thor Duct ® makes every effort to reflect the industry wide understanding of fire resisting duct standards, we do not suggest replacing a thorough research of CEN documents with our Blog posts.  We make every effort to be accurate and true, and, as the passive fire protection industry experience and knowledge grows, we may update our guidance to reflect this.  The design, selection, and supervision of fire strategies must always be managed by qualified Fire Engineers.