Step 3: Underlayment

An underlayment must be applied over the entire deck before the installation of Cambridge Xtreme shingles.

Slopes > 9,5° - 15°

• Parallel to eaves install self-adhesive underlayment, IKO Armourbase Stick or similar self-adhere base sheet. End laps must be 15 cm and horizontal 10 cm or use IKO Armourbase Pro with a horizontal overlap of 50 cm, nailed and glued with IKO Shingle/Plastal Stick.

Slopes > 15° - 20°

• Use IKO Armourbase PRO or ECO underlay or similar base sheet with 50% of overlapping to provide a double coverage. Alternatively, a self-adhesive underlayment in  one layer may be used.

Slopes > 20° - 90°

• The entire roof deck should be covered with any IKO Armourbase underlay or an approved shingle underlament.

Go to "Step 4: Open Valley Method" or download our application guide.