H level 1. The minimum level of preservative treatment required to protect this timber from attack by insects other than termites. Suitable in above-ground, well-ventilated situations protected from weather and wetting.

H codes (H1 to H5) are conditional use codes representing appropriate levels of preservative treatments (against biological decay) that are required for using a specific timber in a specific application and location. Each code (H1, H2, H3, H4, H5) represents a different, required minimum preservative treatment.

Used in field: