Intumescent sheets have ben available for somenconsiderable period of time and have been used in multiple applications,nincluding the upgrading of English heritage doors and used in the protection ofnraised panelling systems which can be exploited by fire.
Whilst, there is no primary test evidence available, fornthe upgrading of heritage doors we would recommend guidance detailed in
Timber panelled doors and fire -nupgrading the fire resistance performance of timber panelled doors and frames,npublication available from Historic England, Customer Services Department, POnBox 569
nSwindon, SN2 2YP. UK