This study assesses the effects of fire-retardant additives such as Zinc borate, Triphenyl phosphate, Aluminum hydroxide and Antimony(III) oxide on the ignitability specified in ISO 5657 and the physical-mechanical properties of PVC materials (Polyvinyl chloride). The fire-retardant additives with different contents (3, 4, 5, 6 and 7 Phr) were investigated. The results of the study on the influence of fire-retardant additives on the properties of PVC materials show that Antimony(III) oxide has the best ability to increase the fire resistance of PVC materials. The PVC samples weren't ignited during the test at a heat flux of 20 kW/m2. The thermal degradation of the samples was studied by using Thermogravimetric Analysis (TGA) under air asmosphere. This report has shown that the use of fire retardant additives can help PVC plastic materials meet the BC2 classification (moderately combustible material) required by QCVN 06:2022/BXD for use in building construction in Vietnam.