In the present study, combustion mechanisms, thermal kinetics, and phases of combustion were investigated for untreated pine and treated MDF, plywood and particleboard samples. Waste wood samples were combusted in air at 10, 20 and 30 degrees C/min heating rates in TGA. As a result of TG analysis, thermal decomposition of treated samples was observed at lower temperatures as compared to the untreated pine sample because of the catalyzing effects of the chemicals in the samples. Therefore, there were less flammable products, lower weight losses in the main oxidation region, decrease in the max. weight loss temperatures and formation of more char for treated samples as compared to untreated pine sample. In other words, chemicals used during production of these samples lead to decrease in the combustibility of the treated samples. Thermal kinetic constants for the samples were calculated by using Coats Redfern and Broido Methods. In order to find out the mechanisms responsible for the oxidation of the waste wood samples, six solid state mechanisms of Coats Redfern Method were tested.