Evo stik fire retardant foam filler evo stik 132658 this foam filler from evo stik is a modified single component polyurethane foam and is ideal for filling or sealing joints and gaps which require fire resistant properties the foam expands quickly after application and cures to a fine honeycomb structure this foam has excellent thermal and acoustic qualities and can be bonded to most building materials evo stik 132658 fire retardant foam filler 700ml