tongue and groove edge on wood panels

Tongue and Groove

Originally contributed by Jeff Butler • last updated 2/18/2021

With both real and faux wood paneling being popular design choices, especially in bathrooms and hallways, the confusion between tongue and groove assembly and traditional shiplap needs to be straightened out.


The term tongue and groove commonly refers to a method of joining two pieces of material, most commonly wood, together from edge to edge. In tongue and groove assembly, one piece of material (i.e. a plank of wood) will have a long tabbed ridge tapered along one edge (aka. the tongue) and a long thin slot cut into the other edge (aka. the groove). When two pieces of material are fixed together, the tongue is inserted into the groove, creating a solid locking bond. The tongue and groove method for fixing materials together is commonly found in the assembly of floors, walls, and ceilings. Traditionally, shiplap relied on a tongue and groove assembly, though modern examples typically use adhesives.

Shiplap vs Tongue And Groove

Quite often, people lump together shiplap and tongue and groove because they appear similar. However, despite their similarities, there is a key difference between them:

  • To start with, modern shiplap is often held in place with adhesives and is more decorative than functional. Pieces are typically just placed up against each other with no tongue or groove on either edge.
  • Traditionally, shiplap joints were formed with overlapping edges, creating a support structure to secure pieces. Instead, tongue and groove joints rely on one of the edges inserting into the other, creating an interlocking support structure.