What is joint filler—and why does it matter before epoxy? Concrete joints (control joints) are intentionally cut into the slab to help manage cracking as the concrete cures and moves over time. Before we install an epoxy system, we apply a professional joint filler to: ✅ level out the surface ✅ reduce visible joint lines in the finished floor ✅ prevent sharp edges from chipping ✅ create a smoother, more seamless look Important: Joint filler helps improve appearance and durability, but concrete c