Does existing GWPP glazing which has no visible marking fitted in nominal fire door need to have intumescent seals fitted retrospectively ? I don't understand why an inspector would request this given that the glass isn't marked. If the original glass isn't broken and the beadings are intact and secure then wouldn't this be deemed as a notional door ?

In the DCLG document 'Fire Safety in Purpose Built Blocks of Flats' the author stated that the term 'Notional' refers to a fire door that at the time the building was constructed met the requirements of the regulations.  As building regulations are not retrospective there is no requirement to upgrade to modern methods.

However, recent product development has meant that fire resistance performance has been improved and that provides us with the opportunity to upgrade existing fire safety measures were such action is worthwhile. So for example, an inspector may recommend that such upgrades be applied in onerous situations such as at sleeping accommodation or on escape routes.