Thermal breaks (TBs) for balconies are emerging insulating devices used at the junction of exterior balcony slabs and interior floor slabs, which is the most critical section of cantilevered balconies. As such, TB structural performance is critical to ensuring adequate structural integrity. This study presents the results of experimental testing of two slabs incorporating commercially available TBs with glass fiber-reinforced polymer (GFRP) bars. The devices in both slabs have GFRP reinforcement ratio of 0.6%, but they differ in their bar length and the number of concrete blocks within the insulation layer intended to resist compression. The two slabs are compared to a third slab with a staniless-steel TB device having a reinforcement ratio of 0.5%. The slabs were 3100x1000x200 mm, tested in flexure as a beam with a 1500 mm long overhanging cantilever. Reversed low-cycle push-pull fatigue loading was carried out to failure at the tip of the cantilever. The failure happened in the cantilevered side in the three slabs just before the TBs. Failure loads of the two slabs with short and long GFRP bars in the TBs were 40 kN, and 63.7 kN while it was 41.2 kN for the one with stainless-steel TB bars. From these preliminary results, TBs with GFRP bars can enhance thermal performance of the TBs because of their low thermal bridging while meeting the design code requirements for structural performance.