Why it matters
Many visible flooring problems begin at the lock: open joints, raised edges, noise, movement and gaps.
Material causes
A brittle core puts the thin tongue-and-groove profile at risk. This can happen when the formula is hard but not tough enough.
Weak board construction can show up first at the locking edge.
Weak lock geometry can chip during handling.
Poor cutting can damage the edge before installation is complete.
Site and installation causes
Even a good product can fail if the floor is forced over an uneven subfloor or installed without proper tolerance.
Uneven floors create pressure points.
Tight edges can restrict movement.
Wrong tapping can crush the lock profile.