Lattice type continuous wire chair
The Standard requires this type of continuous chair to be manufactured from three longitudinal steel wires of the same size in order to carry the design load. In practice, for a lattice support wire spacing of 200mm the top wire needs to be of 5mm size. Beware of non-compliant chairs with wires of a significantly lesser size. The chairs are manufactured in heights from 50mm to 200mm. Greater heights and larger wire sizes are also available upon request to the manufacturers.
Goalpost type continuous wire chair
The Standard requires this type of continuous chair to be manufactured from three longitudinal steel wires of the same size in order to carry the design load. In practice, for a goalpost support wire spacing of 100mm the top wire needs to be of 3.5mm size. Beware of non-compliant chairs with wires of a significantly lesser size. The chairs are manufactured in heights from 30mm to 200mm (standard duty) and up to 400mm (heavy duty). Greater heights and larger wire sizes are also available upon request to the manufacturers.
Individual wire chair
Individual wire chairs can be used where there is no bottom reinforcement off which to support a continuous chair. For example, it can support the top reinforcement in a cantilever slab where there may be no bottom reinforcement. The Standard requires that the legs of the chair are cased in plastic protective tips for a distance of at least 40mm where the chairs are required to support reinforcement off an exposed face, such as the underside of a cantilever slab. They are manufactured in heights from 75mm up to 200mm, and, with linked legs, from 175mm up to 300mm.
