Abstract: A cornerboard assembly comprises an interlocking, opposite direction joint between cornerboard millwork components. Dual male members extend from the end of one of the respective components, forming an opening between the members. The male members and opening formed between the members have planar outer surfaces. The second component comprises an end with a single male member which is configured to be inserted into the opening of the first component. The male member of the second component and the other surfaces at this end also have planar outer surfaces. The planar outer surfaces of the two cornerboards components are configured to be positioned adjacent to each other, in surface to surface contact. An exterior construction glue or similar adhesive is placed on the planar surfaces to fixedly and permanently secure the components.

Abstract: A cornerboard assembly comprises an interlocking, opposite direction joint between cornerboard millwork components. Dual male members extend from the end of one of the respective components, forming an opening between the members. The male members and opening formed between the members have planar outer surfaces. The second component comprises an end with a single male member which is configured to be inserted into the opening of the first component. The male member of the second component and the other surfaces at this end also have planar outer surfaces. The planar outer surfaces of the two cornerboards components are configured to be positioned adjacent to each other, in surface to surface contact. An exterior construction glue or similar adhesive is placed on the planar surfaces to fixedly and permanently secure the components.