Civil Engineering Reference
In-Depth Information
(5) The same component can be used for joists, rafters, purlins, etc.
(6) No on-site waste because the component is manufactured to a precise requirement.
(7) Can be designed to span clear between external walls without internal load bearing
partitions and their associated costs of additional foundations.
(8) Can be designed for top or bottom chords support.
(9) A considerably improved product weight/span ratio compared to solid timber.
One of the first truss system manufacturers to produce a similar product was Gang-Nail
who many years ago produced a product called 'Econoflor'. This earlier version of the 'V'
lattice beam used timber lattice members connected to the top and bottom chords with the
same punched metal connector plates as used for trussed rafters. The labour content in cut-
ting the numerous small lattice timbers and indeed placing them in special jigs made the
product less than economically viable compared to conventional solid timber, and at that
stage Gang-Nail had problems in convincing the authorities of its performance in fire.
Gang-Nail have now reintroduced this construction under the name 'Eco-floor'. They
claim it is now a viable product compared to the alternative forms of manufactured joist
where the floor zone is limited to approximately 200 mm.
Gang-Nail have since produced a new product called Space Joist, illustrated in Fig. 6.16,
using the metal 'V' nail plate construction. MiTek have a similar product called
