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9-09 Timber and Lumber9-09 Timber and Lumber
9-09.1 General Requirements
All timber and lumber shall be sized as indicated in the Plans. All timber and lumber to be painted shall be surfaced on all sides. All timber and lumber to be painted shall be thoroughly air or kiln dried to an equilibrium moisture content and shall be stored in such a manner as to remain in a thoroughly dry condition until placed into the Work.
9-09.2 Grade Requirements
Timber and lumber shall conform to the grades and usage listed below. Timber and lumber shall be marked with a certified lumber grade stamp provided by one of the following agencies: West Coast Lumber Inspection Bureau (WCLIB), Western Wood Products Association (WWPA), Pacific Lumber Inspection Bureau (PLIB), or Any lumber grading bureau certified by the American Lumber Standards Committee. For structures, all material delivered to the project shall bear a grade stamp and have a grading certificate. The grade stamp and grading certificate shall not constitute final acceptance of the material. The Engineer may reject any or all of the timber or lumber that does not comply with the Specifications or has been damaged during shipping or upon delivery. The grading certificate shall be issued by either the grading bureau whose stamp is shown on the material, or by the lumber mill, which shall be under the supervision of one of the grading bureaus listed above. The certificate shall include the following: Name of the mill performing the grading; The grading rules being used; Name of the person doing the grading, with current certification; Signature of a responsible mill official; Date the lumber was graded at the mill; and, Grade, dimensions, and quantity of the timber or lumber For Guardrail Posts and Blocks, Signposts, Mileposts, Sawed Fence Posts, and Mailbox Posts, the material delivered to the project shall either bear a grade stamp on each piece or have a grading certificate as defined above. The grade stamp or grading certificate shall not constitute final acceptance of the material. The Engineer may reject any or all of the timber or lumber that does not comply with the specifications or has been damaged during shipping or upon delivery.
9-09.2(1) Structures
All timber and lumber for structures shall be Douglas Fir-Larch unless specified otherwise in the contract, and shall conform to the following: Materials 2″ to 4″ nominal thick, 5″ nominal and wider (Structural Joists and Planks)No. 1 and better, grade (Section 123-b of WCLIB) or (Section 62.11 of WWPA) Materials 5″ nominal and thicker (Beams and Stringers)No. 1 and better, grade (Section 130-b of WCLIB) or (Section 70.11 of WWPA) Timber lagging for soldier pile walls shall be Douglas Fir-Larch, grade No. 2 or better, or Hem-Fir No. 1. M 41-10 Page 9-75 Timber and Lumber 9-09When the material is delivered to the project, the Engineer will check the order for the appropriate grade stamp. The invoice and grading certificate accompanying the order must be accurate and complete with the information listed above. The grading certificate and grade markings shall not constitute final acceptance of the material. The Engineer may reject any or all of the timber or lumber that does not comply with the Specifications or has been damaged during shipping or upon delivery.
9-09.2(2) Guardrail Posts and Blocks.
Timber and lumber for guardrail posts and blocks (classified as Posts and Timbers) shall conform to the species and grades listed below: Douglas Fir No. 1 and better, grade (Section 131-b WCLIB) or (Section 80.11 WWPA) Hem Fir Select Structural, grade (Section 131-a WCLIB) or (Section 80.10 WWPA) Southern Yellow Pine No. 1 and better, grade (Southern Pine Inspection Bureau) When the material is delivered to the project, the Engineer will check the order for the appropriate grade stamp. The grade markings shall not constitute final acceptance of the material. The Engineer may reject any or all of the timber or lumber that does not comply with the Specifications or has been damaged during shipping or upon delivery. Posts shall be inspected by an American Lumber Standards Committee (ALSC) accredited agency, and bear a quality mark that certifies preservative penetration and retention levels that meet the required AWPA Standard U1–Use Category in Section 9-09.3(1) .
9-09.2(3) Signposts, Mileposts, Sawed Fence Posts, and Mailbox Posts
The allowable species of timber and lumber for signposts and mileposts shall be Douglas Fir-Larch or Hem Fir. Timber and lumber for sawed fence posts and mailbox posts shall be Western Red Cedar, Douglas Fir-Larch, or Hem Fir. Signposts, mileposts, sawed fence posts, and mailbox posts shall conform to the grades shown below: 4″ × 4″ Construction grade (Light Framing, Section 122-b WCLIB) or (Section 40.11 WWPA) 4″ × 6″ No. 1 and better, grade (Structural Joists and Planks, Section 123-b WCLIB) or (Section 62.11 WWPA) 6″ × 6″, 6″ × 8″, 8″ × 10″ No. 1 and better, grade (Posts and Timbers, Section 131-b WCLIB) or (Section 80.11 WWPA) 6″ × 10″, 6″ × 12″ No. 1 and better, grade (Beams and Stringers, Section 130-b WCLIB) or (Section 70.11 WWPA) Page 9-76 M 41-10
9-09 Timber and Lumber9-09.3 Preservative Treatment
9-09.3(1) General Requirements
All timber and lumber requiring preservative treatment shall be treated in accordance with AASHTO M133. As specified by AASHTO M133, the American Wood Protection Association (AWPA) standards shall govern the Specifications. These Specifications include: storing and curing the timber and lumber, the wood preservatives, the preservative treatment process, documenting the results of the treatment, inspection, testing, and the identification of properly treated timber. For guardrail posts, the AWPA Standard U1–Use Category referred to in AASHTO M133 Section 6.1 is hereby superseded as follows: guardrail posts shall be treated according to AWPA Standard U1–Use Category UC4B, except that those installed in Eastern Washington (East of the Cascade Mountain Crest) may be treated according to Use Category UC4A. Unless otherwise specified in the Contract, all timber and lumber shall be treated in accordance with Sections U1 and T1 of the latest edition of the AWPA standards. All cutting, boring, chamfering, routing, surfacing, and trimming shall be done prior to treating. Any field drilling or cutoffs shall be treated by two liberal applications of a compatible preservative. The applications shall be in accordance with the requirements of AWPA Standard M-4 entitled, “Standard for the Care of Pressured Treated Wood Products”. All charges shall consist of pieces of the same species that are similar in form, size, moisture content, and receptivity to treatment. The pieces in the charge shall be separated to ensure contact of treating medium with all surfaces. The method of determining the retention of the preservatives shall be by assay. All orders of treated timber and lumber shall be accompanied by a Certificate of Treatment showing conformance to this specification and AWPA standards record. The Certificate of Treatment shall include the following information: Name and location of the wood preserving company, Customer identification, Date of treatment and charge number, Type of chemical used and amount of retention, Treating process and identification of the Specification used, Boring records verifying treatment penetration for timber and lumber with a nominal dimension of 6" by 6" or larger, Description of material that was treated, and Signature of a responsible plant official. All timber and lumber to be used in aquatic environments, unless specified otherwise in the Contract, shall be chemically treated using Western Wood Preservers Institute Best Management Practices (BMPs). The producer of the chemically treated products shall supply a written certification that the BMPs were utilized, including a description and appropriate documentation of the BMPs used. This information may be included on the Certificate of Treatment record.