There are multiple options for tongue and groove joints, including:
Flush joints
Vee joint
Gap joints
However, tongue and groove boards typically have v-shaped joints. Similar to channel, tongue and groove siding can be installed vertically, horizontally, or diagonally to allow for versatility in design. The grades of tongue and groove follow the same pattern as channel, ranging from clear heart to knotty. Clear heart has little to no imperfections, while knotty consists of knots and blemishes. Every grade is sought after for its own unique appearance.