Pitch the tent, clean the cloth and let it dry. Apply the impregnation agent on the cloth with a plant sprayer or other spray. It is also possible to use a paint roller or brush. The cloth needs to be fully saturated with the impregnation agent. Also treat the inside of the tent. Thoroughly clean any windows with a moist cloth. Do not let the impregnation agent dry on it. Let the tent cloth fully dry. Repeat the treatment if needed.