Aluminium Felt Roof Trim AF1 2.5m Long, 45mm Face, 60mm Leg Method of fixing Nutrim should be fixed by means of Cadmium or Galvanised nails or screws at not more than 300mm (12") centres with the ends of each length firmly secured. A minimum of 8 fixings per length is recommended. A gap of 3mm should be left between each length to allow for expansion. Priming of the fixing leg is recommended. Built up felt roofing The first layer of felt should be dressed over the kerb and the Nutrim fixed into position as described. The top layer of felt is laid in a similar manner over the trim and the top edge turned into the hood thus eliminating the outside edge of the top layer of felt lifting. Mastic asphalt roofing Where Nutrim is used with mastic asphalt this can be fixed in position prior to the laying of the asphalt. On timber kerbs the sheathing felt and expanded metal lathing should be fixed to the inside edge of the fixing arm. On concrete roofs the sheathing felt is stopped at the base of the kerb. The mastic asphalt skirtings are then laid with the top edge turned into the protective hood of the aluminium trim.