For a Cambridge Xtreme roof IKO recommends the open valley method, using Armourvalley (for low slopes ≤15°)
Snap two chalk lines from the ridge to the eaves 8 cm apart increasing in width by 1cm per meter towards the eaves;
Trim the shingles to these lines and cut a 5 cm triangle off the top corner to direct the water into the valley;
Glue the valley end of each shingle with IKO Shingle Stick;
Nail the shingles 5 cm back from the chalk line.
Go to "Step 5: Nailing & sealing" or download our application guide.