3491Preservatives and Preservative Treatment of Wood Products

3491.1SCOPE

Apply wood preservatives and preservative treatment using the pressure process for lumber, timber, piling, posts, poles, plywood, and structural glued laminated members.

3491.2REQUIREMENTS

A Materials A.1 Wood Products Provide timber, lumber, piling, plywood, and posts as required by the C ontract. The Department considers Southern Pine the same as Southern Yellow Pine, and Red Pine the same as Norway Pine. A.2 Preservatives Provide preservatives listed on the APL and then only for the specific application for which they are approved. Provide preservative meeting the requirements of AASHTO M 133 Standard Specification for Preservatives and Pressure Treatment Processes for Timber , as modified herein.

B Preservative Treatment Provide preservative treatment meeting the requirements of AWPA Standard T1 , Use Category System: Processing and Treatment Standard, and the current, applicable AWPA Use Category Standards (U1). B.1 Preparation for Treatment B.1.a General Requirements Because difficulty may be encountered in obtaining the specified retention and penetration, ensure the supplier uses wood Materials having sufficient sapwood thickness to permit the specified penetration and retention. Ensure suitable conditioning and, for some species, incising prior to the treatment, and the use of treating conditions that do not damage the wood in accordance with AWPA Standards T1, U1, and the applicable AWPA Use Category Standards shown in Table 3491.2-1. B.1.b Incising Incise the wood to allow penetration of the preservative. Incise lumber and timbers of species difficult to penetrate, including Douglas Fir, Western Larch, Spruce, Hemlock, Redwood, and Jack Pine before treatment such that the incising will not make the Material unfit for use. Incise pines if predominantly heartwood. The Engineer may waive the incising requirement if the Contractor can meet penetration and retention requirements without incising. B.1.c Seasoning For sawn Material treated with an oil-type preservative and used in buildings or other construction where high moisture content or shrinkage would be objectionable, dry to a moisture content no greater than 19 percent before treatment. Measure the moisture content at a depth equivalent to the required preservative penetration. Unless the Contract requires otherwise, dry lumber no greater than 4 inches in Nominal thickness and plywood treated with a waterborne preservative to a moisture content no greater than 19 percent before and after treatment. C Method of Treatment Unless the Contract requires otherwise, use the preservative Materials listed in Table 3491.2-1 and the APL. Use the same preservative on the entire product provided for each Contract Item, unless the Contract requires otherwise. Use the full-cell process to treat timber products if using with waterborne preservatives. Field treat cuts, bored holes, and damaged treated areas per the requirements of AWPA M4, except do not use coal tar products, including roofing cement. No field treatment shall be applied within 100 feet of surface water, and any spills must be collected and properly disposed of. D Results of Treatment Unless the Contract requires otherwise, provide preservative retention in accordance with Table 3491.2-1. Determine the preservative retention meeting the requirements of the AWPA method referenced in Table 2 of the APL for the treatment of timber products. Provide preservative penetration and other timber product treatments meeting the requirements of AWPA Standard T1 and in accordance with Table 3491.2-1.

Table 3491.2-1 Product and AWPA Use Categories Product Usage* AWPA Use Category AWPA Commodity Specification U1 Section Special Requirements A Piles: A1 Round UC4Cǁ E — B Posts: Fence, guide, and sight: B1 Round UC4Aǁ B — B2 Sawn four sides UC4Aǁ A Subsection 4.3 C Posts: guardrail and spacer blocks, noise walls: C1 Round UC4Bǁ B — C2 Sawn four sides UC4Cǁ A Subsection 4.3 D Poles, lighting: D1 Round UC4Bǁ D — E Lumber and timber: E1 Bridges, prefab (nail laminated) panels, other structural members, Culverts, and other issues UC4Cǁ A Subsection 4.3 E2 Noise wall facing, at or below ground level UC4Bǁ A — E3 Building construction/repair, at or below ground level UC4Aǁ A — E4 Decks, porches, handicap Ramps, boardwalks, or pedestrian Bridge decking UC4Aǁ A Subsection 4.3 F Lumber and timber (not in contact with ground or water): F1 Handrails, Sidewalk plank UC3B A Subsection 4.3 F2 Noise wall facing, above ground level UC3B A Subsection 4.3 F3 Building construction/repair, above ground level UC3B A Subsection 4.3 F4 Bridges, prefab (nail laminated) panels, structural Members, and other uses UC4Cǁ A Subsection 4.3 G Glued-laminated structural members: (Treated after gluing) UC4Bǁ F — H Plywood: H1 In contact with ground or water UC4Aǁ F — H2 For use above ground UC3B F — * Refer to the APL for information regarding which products may be used on which applications, such as near water, residential, or recreational areas. ǁ For products listed by the AWPA or approved by the International Code Council-Evaluation Service (ICC-ES). Include passing results from the test method AWPA E7, Standard Field Test for Evaluation of Wood Preservatives to be Used in Ground Contact (UC4A, IC4B, IC4C) ; Stake Test. Do not substitute test method AWPA E20, Standard Method of Determining the Depletion of Wood Preservatives in Soil Contact. E Handling Treated Products Care for and handle preservative treated wood products in accordance with the requirements of AWPA M4, Standard for the Care of Preservative-Treated Wood Products. F Product Marking Hammer, heat brand, dye stamp, or metal tag the treated Material marking the species, commercial grade, and type of treatment meeting the requirements of AWPA M1, Standard for the

Purchase of Treated Wood Products, and AWPA M6, Brands Used on Preservative Treated Materials, except brand piles on the butt end. Include the charge number in the markings on treated piles. The Contractor may bundle sawn Materials no greater than 2 inches in Nominal thickness and plywood treated with oil-type preservatives with the tags attached to the bundles. For sawn Materials treated with waterborne preservatives, the Contractor may dye stamp the information on the outer pieces of the bundle instead of using bundle tags. G Framing Provide framing with bored holes in accordance with Table 3491.2-2: Table 3491.2-2 Bored Hole Diameter Requirements Hardware Types Diameter Round drift bolts and dowels Equal to diameter of bolt or dowel Square drift bolts and dowels 1/16 inch greater than least dimension of bolt or dowel Machine bolts 1/16 inch greater than diameter of bolt Rods 1/16 inch greater than diameter of rod Lag screws No greater than 1/16 inch of the body diameter of the screw at the root of the thread

3491.3SAMPLING AND TESTING

Provide for the inspection of Materials and treatments meeting the requirements of AWPA M2, Standard for the Inspection of Preservative Treated Products for Industrial Use, by an independent commercial inspection agency. Only use agencies approved by the Materials Engineer for Materials provided to Department Projects. Engage the inspection agency directly or through the supplier of the treated wood products. The Department will include the cost of inspection with the relevant C ontract Pay Items for treated wood products. Submit to the Engineer a manufacturer’s Certificate of Compliance with each shipment of treated Materials. Submit the Certificate of Compliance, the inspection report from the commercial inspection agency, and the treating company’s report of treatment to the Engineer. The Department may inspect treated products upon delivery. Consider the Department’s inspection results conclusive and binding. Paints and Enamels