Available to suit 100 or 140mm thick, wall construction. Each lintel offers a minimum of 1⁄2 hour fire resistance, catering for every circumstance 100 x 65mm. Starting at 600mm then every 300mm up to 2700mm. All 65mm deep lintels must not clear a span of more than 1800mm. 140 x 100mm. Starting at 900mm and then every 300mm up to 2700mm. Like the 100 x 65mm, these can be installed upright or on edge.