In order to ensure fire resistance with wooden structures, self-extinguishment and carbonization control are necessary, but as the required fire resistance time increases, the cross section becomes larger. Therefore, in this study, bench-scale and full-scall beam heating tests were conducted on wooden fireproof structural members using fire-retardant cedar for the barrier layer, using the laminated direction and the amount of chemicals as parameters. As a result, the difference in the effect of the barrier layer during heating and cooling, and the cross-sectional configuration of the member that reduces the volume and weight of the barrier layer were clarified.