H3 Treated Pine F7 140 x 35 Timber - 6.0m LengthsH3 Treated Pine F7 140 x 35 Timber 6. 0m Lengths H3 Structural Treated Pine is used for outdoor, external above ground structural use. Each piece of structural timber is treated for borers, termites and is able to be subjected to moderate wetting in a well ventilated area for up to 20 years. Please refer to your local building codes and regulations for required treatment types and levels. Common uses for H3 Structural Treated Pine are decking sub