Intumescent coatings are among the most e7cient ways of 5re retarding 6ammable materials. The coatings swell under the in6uence of heat and form a thick porous charred layer. The latter perfectly insulates the substrate against an excessive increase of temperature and oxygen access. In order to make intumescent coatings e4ective, proper selection of the essential components, i.e. carbonizing, foam-producing and dehydrating materials, is necessary. The choice of components for an intumescent 5re retardant composition has an essential e4ect on the rate of charred mass formation and its structure. The in6uence of di4erent modi5ers added to amino resins during the process of condensation on 5re retardant and heat-insulating e7ciency of intumescent coatings for wood is presented. The 5reproo5ng e7ciency was studied by determining the heat release rate, the e4ective heat of combustion, the mass loss rate and the speci5c extinction area during the combustion of samples was investigated. The most e7cient coating, both from the point of view of 5re retardancy and heat insulating properties, was found to be that based on amino resin prepared from urea, dicyandiamide and monoammonium phosphate and dextrin. The exposing of wood coated with urea-dicyandiamide-phosphate-formaldehyde resin supplemented by dextrin to a heat 6ux of 35 kW/m for 30 min did not result in ignition and no increase occured in heat release, mass loss rates or in e4ective heat of combustion.