Clapboard siding is a type of siding made from wedge-shaped boards which are designed to overlap with each other. The individual boards used in clapboard siding are known as clapboards; clapboard siding may also be referred to as bevel, lap, or weatherboard siding in various regions of the world. Many people find clapboard siding aesthetically pleasing, and it is associated especially with frame homes built in the American region of New England.

Historically, clapboard siding was made by splitting wooden boards into thin strips which could be nailed onto the side of a home to protect it from the weather. The overlapping design allowed the wood to expand and contract with changing weather, and it encouraged rain and snow to run off the side of the structure, rather than penetrating it and causing damage. The word “clapboard” comes from the Dutch klappen, which means “to split.”

When clapboard siding is applied, it is layered like shingles, with the thin side of each clapboard lying under the thick edge of the clapboard on top. Clapboards may be left unfinished, or they may be painted, depending on personal taste, and a wide variety of woods have been used to make clapboard siding historically. Red cedar has been a popular choice for centuries, because it is naturally weather and pest resistant, but other soft and hard woods can be used as well.

Due to the growing scarcity of wood and concerns about the ethics of using wood in construction, clapboards today may be made from metal, various plastics, and fiber cement, rather than wood. In fact, in some areas, the use of wood for clapboard siding is banned. Many of these materials are actually more durable than wood, making them a better choice for weather protection, and once they are painted, it is hard to distinguish them from traditional wooden clapboard siding.

Repairing clapboard siding can be time consuming, because of the way it is initially applied. For this reason, people tend to stay on top of their clapboard maintenance, painting their clapboards regularly and promptly removing boards which show signs of rot and damage. Removing and replacing clapboards requires a skilled hand, as the goal is to remove the damaged clapboard without breaking or damaging the surrounding clapboards.