Section 2: Greenhouse Benching Materials
The support structure of elevated benching systems may be made of concrete blocks, wood, or plastic. However, galvanized steel or aluminum are most commonly used to make the structural support of elevated benches.
The surface of elevated benches may be made of expanded metal, wire, wood, hardened plastic, chain-link fence, snow fencing, or concrete. Each of these materials has advantages and disadvantages. Hardened plastic is resistant to water and chemicals and can support heavy loads, but hardened plastic benches are expensive and typically only used in special situations such as propagation houses and retail displays. Another use for plastics in greenhouse benching is in the production of the bench liners used in ebb-and-flow benching systems. Wood is readily available and can be lower in cost than other materials (or more expensive than some materials). However, wood must be treated to prevent decay and can be difficult to clean. Wire and chain-link fence are low in cost, but because they bend easily, they require a significant support structure underneath to prevent bending and warping and to maintain a level production surface. The most common benching material is expanded metal. It is preferred because it is relatively low in cost, strong, rigid, and requires minimal support underneath. Expanded metal is also low maintenance and has a long lifespan.
Floor-based production surfaces may be made from standard or porous concrete. Floor-based production surface may also be constructed of compressed soil covered with a thick polypropylene mat that covers the ground but allows drainage. Floor-based production surfaces may also be covered with small gravel.
