To protect the Rundāle Palace from devastating fire, its wooden structures are regularly - every several years - treated with a fire retardant. In the recent competition, Vincents Polyline's fire retardant Inwood Fire B was chosen as the best fireproof treatment agent. The mechanism of impact of the fire retardant Inwood Fire B is as follows a film coating is formed on the wooden surface, which under the influence of flame turns into a dry foam layer and prevents fire accessing the wood surface and prevents spreading the fire.