Fixing Instructions - Fixing is easy!
Therma-Flect Roof Board lays in between the trusses and the overlaps lay on top of the timber trusses thereby giving a double overlap at each truss. Once the counter batten is nailed vertically all vertical laps are sealed. Horizontal laps are not sealed.

1. Lay 400mm. or necessary width of eaves membrane to lowest section of roof, allowing felt to drape into gutter, allowing effective rainwater discharge into gutter.

2. Starting from lowest right hand section of roof, take the first Therma-Flect Roof Board, peel away 200mm of bubble foil including the overlap on the length, from the insulation. Place the board in position with the exposed insulation board fitting below the tilt board, and the peeled bubble foil over both the tilt board and the eaves felt. This maintains an effective water barrier at eaves level.

Care should also be taken to ensure that the Therma-Flect Roof Board is sealed against the vertical cavity boards.

Carry on laying lowest roof board along full width of roof, Boards should be tacked into position through the clips. Fit lengths of counter batten (minimum 12mm) to all rafters. Nailing only where the roof boards are in position (200mm centres). Fit tile battens of correct gauge to areas where roof boards are fitted, proceed up the roof with next row of roof boards, carefully placing roof boards below counter battens, making sure all overlaps are correct, before nailing next section of counter batten and next section of tile batten.

Narrow Truss Spacings
Where truss spacings are narrower than standard widths, roof boards need to be cut. Measure the space between the trusses, remove clips, then peel sufficient membrane back to expose the polyurethane or polystyrene, mark, then cut with wood saw. Re-fit clips and fit board. Take care not to cut through membrane.

Hips and Ridges
• Cut roof boards to be a close fit at ridge level and at hip line.
• Fit a length of 400mm bubble foil as ridge membrane to form overlaps.

Valleys
For valley use, first roll a length of tilt board membrane down the length of the valley, in a width to suit your application. Then proceed with the remainder of the roof covering, see fixing instructions.