Weatherboarding

Clapboard, also known as bevel siding or lap siding or weatherboard (with regional variants as to the exact definitions of these terms), is the cladding or ‘siding’ of a house consisting of long thin timber boards that overlap one another, either vertically or horizontally on the outside of the wall. They are usually of rectangular section with parallel sides. Some horizontal sections have a tongued and grooved joint arranged to link the boards together, they can also be similar to North American riven clapboards of triangular or "feather-edged" section where the upper edge is the thinner one. Generally vertical boarding uses rectangular sections placed alternatively heart side in, heart side out (heart side means the side of the wood being nearest the heartwood, the central sap-less core of the original treetrunk). This is done in order to encourage the boards to cup against one another in a similar fashion to traditional terracotta roof tiles. This detail can also be used in an angled roof condition.