ITEM 713 – TREATED AND UNTREATED TIMBER

713.1 General Requirements

713.1.1 Timber

It shall be of the species specified on the Plans. Unless otherwise noted on the Plans or in the Special Provisions only the best grade shall be used. It shall be free from loose knots, splits, worn holes, decay, warp, ring separation or any defects which will impair its strength or render it unfit for its intended use. Any specie specified on the Plans may be used for untreated timber and if that specie is not available, a specie of equivalent strength and durability may be used if authorized by the Engineer. If the timber is to be treated, only those species shall be used which are known to posses properties which make them favorable to treatment.

713.1.2 Paints

When painting of timber is required, the paint shall conform to the requirements of Item 709, Paints.

713.1.3 Preservatives

It shall be creosote oil or creosote-petroleum oil blend as called for on the Plans or by the Special Provisions and shall conform to the Specification for timber preservative of AASHTO M 133. When timber is intended for marine use, the creosote petroleum oil blend shall not be used.

713.2 Untreated Structural Timber and Lumber

Structural timber, lumber and piling shall conform to the applicable requirements of AASHTO M 168 or equivalent. No boxed heart pieces of Douglas fir or redwood shall be used in outside stringers, floor beams, caps, posts, sills or rail posts. Boxed heart pieces are defined as timber so sawed that any point in the length of a sawed piece, the pith lies entirely inside the four faces.

Yard lumber shall be of the kinds and grade called for on the Plans. Round poles and posts shall be of the kinds indicated on the Plans.

713.3 Treated Structural Timber and Lumber

            Structural timber, lumber and piling to be treated shall conform to the applicable requirements of AASHTO M 168 and M 133 or equivalent.

The type of treatment to be used will be shown on the Plans or in the Special Provisions and shall conform to the applicable requirements of AWPA standard C1and C14 or equivalent.