Polyurethane-polyisocyanurate (PUR-PIR) foams were modified by addn. of Al(OH)(3) (20% by mass) to reduce their flammability and glycolyzed in diethylene, ethylene and 1,3-propylene glycols at 200 degrees C in presence of ethanolamine and Zn stearate. The glycolyzates were recycled and used for manufg. new PUR-PIR foams. The foams showed a limited flammability, satisfactory mech. properties, low water intake, high content of closed cells and low thermal cond.