Sarking

Sarking is a strong, moisture proof, reflective, metallic building paper that is usually concealed within, or is laid next to, a wall or roof frame which is placed over the rafters but underneath the roof batons. The sarking runs to the roof gutter and the reflective side should always face outwards to repel heat. Reflective foil sarking is used to reflect heat and stop condensation forming on the underside of a roof.

WIKIPEDIA ENTRY FOR BUILDING INSULATION.

Insulation Sarking Picture   Insulation Sarking 2 Picture   Insulation Sarking 3 Picture