Flame spread during combustion of natural and synthetic materials is a factor, determining the fire intensity and dynamics, therefore it is important to ensure fire protection of building structures. Timber is becoming more and more widely used in construction due to many advantages. However, because of dangerous shortcomings such as flammability and smoke generation, timber fire protection is required. The best effect is achieved through the use of geocement-based intumescent coatings applied to the timber surface. The basic fire-resistant properties including flammability, smoke generation and flame spread on the surface of the timber, protected by a geocement-based coating, were defined. The test for determining the flammability group of timber, protected by a geocement-based coating has shown flame-retardant properties of the material, namely, the weight loss – 4.4 %, and the maximum temperature of the combustion gases – 185 °C. The test for determining the smoke-generation ability has shown that in the combustion mode – 84.9 m2/kg, in the smoldering mode – 256.4 m2/kg, and flame spread index on the timber surface was 56.7. After tests for determining the fire properties, the investigated material refers to flame-retardant material with moderate smoke generation and low index of flame spread on the surface. Using timber, protected by a geocement-based coating in construction is effective and safe.