Batten

A batten is a thin strip of solid material, typically made from wood, plastic or metal. Battens are used in building construction and various other fields as both structural and purely cosmetic elements. In the steel industry, battens may also be referred to as "top hats", in reference to the profile of the metal.

Battens are used in building construction in various ways:

• Roofing battens are used to provide the fixing point for roofing sheet or roof tiles. The orientation and spacing of the battens depend on the type of roof. Battens may be oriented at right angles to the trusses or rafters of a roof like purlins. They may be parallel to the slope of the roof, as on a batten-seam roof, where the battens cover seams in the roofing material and are themselves covered by metal caps. Some roofs may use a grid of battens in both directions, known as a counter-batten system.
• Batten trim or batten molding is a thin strip of trim, typically with a rectangular cross-section, used to cover seams between panels of exterior siding or interior paneling.
• Board-and-batten siding is an exterior treatment of vertical boards with battens covering the seams.
• Battens are used for solid wall insulation. Regularly spaced battens are fitted to the wall, the spaces between them filled with insulation, and plasterboard or drywall screwed to the battens. This method is no longer the most popular, as rigid insulation sheets gives better insulation (with battens bridging the insulation) and take less time to fit.

Other uses

• In sailing, battens are long, thin strips (usually fiberglass or some similar material nowadays, but historically wooden) used to support the roach of a sail. They are also used on tall ships to form the ladders up the shrouds in a fashion similar to ratlines. They are also used to help secure tarpaulins over hatches, thus giving rise to the common phrase "batten down the hatches!", meaning to secure the hatches against an approaching storm. Used by analogy in non-sailing contexts, it means to prepare to weather a coming storm, whether that storm is metaphorical or real.
• In cabinetry, battens may be used to strengthen panels made up of multiple boards, as in a batten door, or to cover joins.