"Live Edge" is another term for "Natural Edge", ie. boards that are not trimmed to parallel edges but retain the shape of the log, including a bark edge. Such boards have to be installed horizontally. If the cladding needs to have a 60/60/60 FRL the detail shown in our Technical Design Guide #04 can be used.

Clause 6.3.6.6 only requires lintel trimmers to be designed as per sill trimmers (Table 6.3) if "the distance between the top of the window or door to the top plate exceeds 650 mm". Sill trimmers and lintel trimmers (if required) act similarly to wind beams in resisting horizontal wind loads. Unfortunately the 650 mm dimension isn't illustrated by a diagram in AS 1684.2, but we interpret it as the distance from the underside of the lintel trimmer to the top of the top plate, ie. the area of the frame impacted by wind.

The main purpose of a lintel trimmer is to provide fixing for the internal linings, since it "trims" the lintel to the same line as the wall studs. As long as your lintel is correctly sized, we don't see any problem using a 90 x 35 trimmer, either fixed to the underside of the lintel or supporting jack studs as per AS 1684.2, Figure 6.9. Also the required 15 mm clearance between the top of the window frame and the lintel trimmer must be maintained to allow for deflection.