Building component structure, or building components

An arrangement of panel shaped or strip shaped building members made of wood, wood material or wood based material comprising:

• first and second components each having a top surface, a bottom surface and at least one edge, with a groove defining an opening through the at least one edge of the first component and a tongue projecting from the at least one edge of the second component for receipt through the opening when the edges of the components are in abutment;
• the groove having first and second walls converging with respect to the opening from the edge of the first component inward toward a groove bottom, with at least the second wall having an outer portion of a selected extent and an inner portion;
• a contact surface disposed proximate the opening and extending obliquely from the second wall with respect to the top or bottom surface of the first component in a divergent direction with respect to the opening of the groove, the contact surface having an extent less than and an angle steeper than the outer portion of the second wall, and
• the tongue having a first surface for abutting the first wall of the groove when inserted into the groove and a second surface having at least an inner portion abutting and complementing the outer portion of the second wall and a shoulder abutting and complementing the contact surface to positively retain the tongue in the groove.