Section 716. - MATERIAL FOR TIMBER STRUCTURES

716.01 Untreated Structural Timber and Lumber. Delete the first paragraph and substitute the following:

Conform to AASHTO M 168. Furnish an inspection certification from an agency accredited by American Lumber Standards Committee as to the species and grade. Mark all pieces with the inspection service, grade designation, species, and inspector identity.

Ensure that all structural timber and lumber are seasoned and dried at the time of fabrication. Material that has become twisted, curved, or otherwise distorted prior to assembly into the final structure may be cause for rejection.

716.03 Treated Structural Timber and Lumber. Delete the text and substitute the following:

Furnish wood according to Subsection 716.01. Incise all wood and make all dimensional cuts and holes in the wood before pressure treatment. Treat the wood and mark each piece of treated timber according to AASHTO M133. Treat glued laminated timber members according to AWPA Standards C14 and C28. Use the type of treatment and minimum net retention of preservative as shown on the contract drawings.

Treat timber members according to “Best Management Practices for the Use of Treated Wood in Aquatic Environments” (BMPs) as published by Western Wood Preservers Association (WWPA), latest edition.

All treated timber members shall bear an approved American Lumber Standards Committee (ALSC) quality mark assuring treatment conforms to the appropriate AWPA standards.

Provide certification for each lot of treated wood indicating preservation used, penetration in inches, and retention in pounds per cubic yard (assay method). Provide written certification that BMPs were utilized in treating timber members, including a description of the BMPs used.

Add the following subsection:

716.04 Structural Glued Laminated Timber. Furnish structural glued laminated timber according to American Institute of Timber Construction (AITC) 117. Fabricate according to the combination and grade as indicated in the contract. Fabricate structural glued laminated members according to ANSI/AITC A190.1, Structural Glued Laminated Timber.

Manufacture members as industrial appearance grade for wet use conditions, using a phenol-resorcinol resin type of adhesive throughout. Use only single- or multiple-piece laminations with bonded edge joints.

Straight or slightly cambered members which are to be loaded perpendicular to the wide face of the laminates shall be stamped “top” on the top at both ends of the beam.