What is the difference between a transition strip and a threshold in tile installations?

• A. A transition strip is used to join two different floor coverings; a threshold is a raised strip at a doorway to transition between surfaces.
• B. A threshold is used to join two different floor coverings; a transition strip is a raised strip at a doorway to transition between surfaces.
• C. They are the same thing; the terms are interchangeable.
• D. A transition strip is only for walls; a threshold is only for stairs.

Answer: (D)

In tile installations you’re looking at two different roles for edge pieces. A transition strip is an edge piece used where two floor coverings meet or where a single surface needs a smooth, protected edge—think tile meeting wood, carpet, or another tile, or a seam across a doorway. It helps level small height differences and creates a clean transition between materials.

A threshold, by contrast, is the door sill that sits at a doorway between two spaces. It defines the boundary and often handles height differences or weather sealing from indoors to outdoors. It isn’t meant to trim an interior edge between materials in the middle of a room.

So the idea that a transition strip is for walls or that a threshold is for stairs isn’t accurate—transition strips trim floor edges, not walls, and thresholds belong at doorways, with stairs using separate edge profiles like stair nosings.