141mm face 90mm leg 3m long Drip Edge Trims are fitted to the lowest edge of the roof where the rainwater flows into the gutter. To ensure the vertical leg of the trim sits into the centre of the gutter, the trim needs to be packed out by using two support battens, the first fixed just below the level of the deck and the second 10mm below the first, to allow the trim to sit flush with the roof.