Our recommendation for the structural steel beams supporting the mezzanine floor would be to use boarded protection, as per the details within our Technical Data Sheet TDS038 30 & 60 minute & TDS039 90 & 120 minute PROMATECT®-250 steel joisted mezzanine floor. Intumescent Paint does not provide full insulation protection therefore this element of the system would be compromised if the beams were to be painted rather than boarded. 

It would be possible to use Intumescent Paint protection on the structural steel columns, however we would recommend overlapping the PROMATECT®-250 a minimum of 100mm down from the top of the column over the paint and capping off the encasement, as per industry guidance from the ASFP on interfaces between paint and board protection. More information can be found in their Technical Guidance Document 8.