Abstract THERMAL BARRIER LAMINATES ARE DISCLOSED HAVING A POLYISOCYANURATE FOAM CORE, OUTER FACING SHEETS AND ONE OR MORE INNER LAYERS OF HEAT RESISTANT MATERIAL EXTENDING THROUGH THE CORE SERVING TO SEPARATE THE CORE INTO TWO OR MORE DISTINCT LAYERS. THIS STRUCTURE LEADS TO GREATLY ENHANCED RESISTANCE TO HEAT PENETRATION AND TOTAL DEGRADATION OF THE THERMAL BARRIER UPON EXPOSURE TO FIRE. INCORPORATION OF THE THERMAL BARRIER LAMINATE INTO A BUILD-UP ROOF NOT ONLY PROVIDES THERMAL INSULATION BUT FORMS A FIRE RETARDANT BARRIER ADEQUATE TO MEET EXISTING CONSTRUCTION CODES FOR SUCH STRUCTURES. THE THERMAL BARRIER LAMINATES CAN ALSO BE EMPLOYED IN A VARIETY OF WAYS IN WHICH EXISTING BARRIERS ARE EMPLOYED, E.G. BUILDING PANELS, FIRE DOORS, PIPE INSULATION AND THE LIKE.