ABSTRACT The wood, like other materials, cannot indefinitely resist the action of the fire without undergoing deterioration. In this work, low-density wood panels were impregnated with partially hydrolyzed ethyl silicates The results obtained in laboratory, with different degree of penetration and retention of the impregnant material, showed through tests in a Horizontal-Vertical Cabinet, a LOI Chamber and an Inclined Tunnel a high fire retardant efficiency.