How are wood siding planks typically installed horizontally?

Wood siding planks are typically installed horizontally by lapping them using clapboard. This method involves overlapping the bottom edge of one board over the top edge of the board directly beneath it. The lapped construction helps create a weather-tight seal, preventing water from seeping behind the siding, which is essential in protecting the underlying structure from moisture damage. Additionally, the clapboard design capitalizes on gravity, allowing rainwater to run off rather than pooling. This overlapping technique not only enhances durability but also contributes to the aesthetic appeal of the structure, as it provides a traditional and visually pleasing appearance.

Other methods, such as aligning the edge treatments with the wall or relying solely on vertical supports, are not standard practices for horizontal wood siding installation and do not emphasize the necessity of overlapping layers for weather resistance. While maintaining a straight line without overlaps may seem visually appealing, it would compromise the protective functionality of the siding, making it susceptible to moisture damage.