Edge Trim is not required unless you desire a more completed appearance to your flooring mat. G‑Floor Edge Trim is a 4” single-slotted polyvinyl strip which has a tapered edge to help create a finished edge and look. After insertion into the edge trim piece, your mat should not fit snugly - leave one inch of room to allow for expansion and contraction with temperature changes. You'll find Edge Trim info at: https://bltllc.com/gfloor-universal-flooring/accessories/