Clapboard (architecture)


Clapboard (architecture)
A New England saltbox house with unpainted clapboard siding

Clapboard, also known as bevel siding or lap siding or weather-board (with regional variants as to the exact definitions of these terms), is a board used typically for exterior horizontal siding that has one edge thicker than the other and where the board above laps over the one below. It is often found in New England architecture.

Clapboards, can be cut from trees two different ways: flat-grain boards or vertical-grain boards. Flat-grain boards are to be cut tangent to the annual growth rings of the tree, and vertical-grain boards are to be quartersawn or cut at right angles of the annual growth rings of the lumber. The more commonly used boards in New England are vertical-grain boards. Depending on the diameter of the log, cuts are made from 4 1/2" to 6 1/2" deep the full length of the log. Each time the log turns for the next cut, it is rotated 5/8" until it is rotated a full 360 degrees. This gives the clapboard its taper and true vertical grain.

Clapboard siding got its name from the Dutch klappen, meaning "to split". It was originally split by hand from logs in a radial manner. Later, the boards were radially sawn in a mill.

In Australia and New Zealand, this kind of cladding is known as weatherboard, and was extensively used in forested regions from the Colonial period to the mid-20th Century.

Newer, cheaper designs often imitate the form of clapboard construction as "siding" made of vinyl, aluminum, or fiber cement.

See also