A laboratorial study was carried out to evaluate the fire performance of two fire retardant base coatings (CB-533 and CB-534) and two fire retardant top coatings (CB-535 and CB-536). These base and top coatings were specially developed by Inortech Chimie Inc. for oriented strand board (OSB) and low-density ceiling tile applications. Six combinations of the base and top coatings were applied on OSB and ceiling tile specimens and all of the three-layer coated panels were tested for flame advance, panel consumption, insulation value and char index according to ASTM D 3806. The test results indicated that all coating combinations improved the fire performance of OSB and ceiling tile, as compared to the uncoated panels. The most effective coating against flaming was CB-534/CB-534 (three-layer base coating), followed by CB-534/CB-535 (two-layer base coating/one-layer top coating), among the six base/top coating combinations evaluated.