SS236-002020-01.docx
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- Attached to
- Construction, University Drive Bike Lanes
- Solicitation number
- IFB-114424
- Issued by
- Fairfax County, Virginia
About this file
This document is a 2020 Road and Bridge Supplemental Specifications guideline issued by the Virginia Department of Transportation (VDOT) on May 14, 2021, establishing requirements for wood products used in state transportation projects. The specifications detail material standards for structural timber, lumber, timber piles, and wood preservatives across various applications including bridges, signs, guardrails, fences, and signalization systems. Structural timber and lumber must conform to AASHTO M168 with specific species and grade requirements based on application type; for example, bridge timber must be Southern Pine with a minimum fiber bending strength of 1,550 psi, while sign posts must meet 1,100 psi with Southern Pine No. 2 or No. 1 depending on dimensions. Timber piles must conform to ASTM D25 standards with clean peeling, minimum 31-inch butt circumference, and steel or cast iron points, and must be branded prior to shipment with supplier information and treatment specifications.
Wood preservatives must conform to AWPA U1 Standards and be selected based on use category exposure conditions ranging from UC4A (above ground and ground contact) to UC5B (salt and brackish water). Table 1 specifies preservative options including Chromated Copper Arsenate (CCA), Creosote, Pentachlorophenol (PCP), and Dichloro Octyl Isothiazolin (DCOI) with retention rates in pounds per cubic foot varying by commodity type and application, such as 0.60 pcf CCA retention for bridge lumber. Hand-contact surfaces such as handrails and playground equipment require non-arsenical water-borne preservatives per Table 2, including Alkaline Copper Quat (ACQ), Copper Azole (CA), and Micronized Copper Azole (MCA), with fasteners requiring 304 or 316 stainless steel or hot-dipped galvanized steel compliant with ASTM A153 or A653. Additional requirements address field cuts and damage to treated wood, which must be protected using AWPA Standard M4 guidelines with three heavy brushed applications of preservative, and all treated timber must be supplied from VDOT Approved List #45 facilities.
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Guidelines: For use on all projects
SS236-002020-01 May 14, 2021
VIRGINIA DEPARTMENT OF TRANSPORTATION
2020 ROAD AND BRIDGE SUPPLEMENTAL SPECIFICATIONS
SECTION 236 – WOOD PRODUCTS
SECTION 236 WOOD PRODUCTS of the Specifications is amended as follows:
236.02 – Detail Requirements is replaced with the following:
(a) Structural timber and lumber shall conform to AASHTO M168. The species and grade of structural lumber shall be as shown on the plans. .
Except as otherwise specified, the species and grade of structural lumber, timber, and posts for the following applications shall be as follows:
1. Bridges shall be at least 1,550(psi) Fb (Fiber Bending) and:
· 5 inch by 5 inch and larger: Southern Pine, No. 1 Dense.
· 2 inch through 4 inch by 2 inch through 4 inch: Southern Pine, No. 1 Dense.
· 2 inch through 4 inch by 5 inch and through 6 inch: Southern Pine, Non-Dense Select Structural
· 2 inch through 4 inch by 8 inch only: Southern Pine, Non-Dense Select Structural.
· 2 inch through 4 inch by 10 inch only: Southern Pine, Select Structural.
· 2 inch through 4 inch by 12 inch only: Southern Pine, Select Structural.
2. Signs shall be at least 1,100 (psi) Fb with material being dressed on all sides and:
· 4 inches and less in the least dimension: Southern Pine, No. 2.
· Over 4 inches in the least dimension: Southern Pine, No. 1.
3. Guardrail shall be at least 1550 (psi) Fb Southern Pine, No. 1 Dense.
4. Fence shall be Southern Pine, No. 2, for line, corner, and brace units.
5. Signalization and electrical service shall conform to ANSI Class 05.1. Sawn material, both rough and dressed, shall be certified by the mill as to grade and shall be grade marked in accordance with the grading rules and basic provisions of the American Lumber Standards (PS-20-70) by a lumber grading or inspection bureau or agency approved by the Department. The grade mark shall be applied after dressing if the sawn material is dressed.
(b) Timber piles shall conform to ASTM D25. Piles shall be clean peeled and have a butt circumference of at least 31 inches. The Engineer will accept piles for fender systems or other nonload bearing uses under the following criteria provided the piles can be properly driven: A straight line from the center of the butt to the center of the tip may lie partly outside the body of the pile, but the distance between the line and pile shall be not more than 1/2 percent of the length of the pile or 3 inches, whichever is smaller.
Points for timber piles shall be steel or cast iron and of a shape that will allow a secure connection to the pile and withstand driving.
Timber piles shall be branded prior to shipment with the supplier brand, year of treatment, species of timber and preservative treatment, retentions, class, and length. Brand symbols shall conform to AWPA M6.
(c) Wood Preservatives - Wood preservatives shall conform to the requirements of the American Wood Protection Association (AWPA) U1 Standards. The AWPA designates the different wood exposure conditions in the following “Use Category System”:
UC4A: Above ground, ground contact, fresh water contact or other conditions favorable to wood deterioration. (For Example: sign posts, fence posts and gates).
UC4B: Ground contact in severe environments, critically important components and salt water splash zones (For Example: bridge timbers, bridge decking, guardrail posts and offset blocks).
UC4C: Ground contact in very severe environments, or climates with an extremely high potential for deterioration of critical structural components.
(For Example: foundation pilings).
UC5B: Wood exposed to salt and brackish water (For Example: piles, bracing and bulk-heads).
Wood preservatives for Highway Construction and Hand-Contact Surfaces, listed in Tables1 and 2 below shall be used according to their suitability for the wood exposure condition and shall not be used interchangeably.
1. Wood used for Highway Construction (including but not limited to - bicycle trails, pedestrian overlooks, maintenance applications for posts (sign, fence, guardrail), bridge decking, gates, stair treads, and offset blocks, piles, timbers, and composites) shall be treated with the following preservative per Table 1 below:
Chromated Copper Arsenate (CCA) Creosote Pentachlorophenol (PCP) Dichloro Octyl Isothiazolin (DCOI)
Table 1 – Southern Yellow Pine Treatments & Retentions for Highway Construction per AWPA
| Commodity Specifications |
| Use Category |
| Preservative Retentions |
Waterborne (pcf) Oil borne (pcf)
| Desig |
| Wood Usage |
| CCA |
| Creosote |
| PCP |
| DCOI |
| A |
| Sawn Products: |
Boards, lumber and timber
UC4A
0.40
10.0
0.50
0.15
| Lumber and Timber products for bridge structures, bridge decking, gates, and stair treds |
| UC4C |
| 0.60 |
| 12.0 * |
| 0.50 |
| 0.2 |
| B |
| Posts: |
Round, 1/2 and 1/4 round, building, fence and sign posts, poles < 16 feet in length.
UC4A
0.40
N/A
N/A
0.13
| Guardrail Posts and offset blocks |
| UC4B |
| 0.50 |
| N/A |
| N/A |
| 0.17 |
| E |
| Round Timber Pilings: |
Pilings and foundations for land and fresh water use
UC4C
0.80
12.0
0.60
0.2
| F |
| Wood Composites: |
Plywood
UC4A
0.40
10.0
0.50
0.2
| **Glue laminated members (glue then treat) |
| UC4A |
| N/A |
| 10.0 |
| 0.60 |
| 0.2 |
| **Glue laminated members (treat then glue) |
| UC4A |
| 0.40 |
| 10.0 |
| 0.60 |
| 0.2 |
| Laminated veneer lumber |
| UC4A |
| N/A |
| 10.0 |
| N/A |
| N/A |
| G |
| Marine Applications (in or above salt water, brackish water, or tidal water) |
Plywood & Solid Sawn
UC5B
2.5
25.0
| Piles (outer zone/inner zone) |
| UC5B |
| 2.5/1.5 |
| 20.0 |
| N/A |
| N/A |
| Sawn - Dual treatment: CCA with CR |
| UC5B |
| 1.5 |
| 20.0 |
| N/A |
| N/A |
| Piles - Dual treatment: CCA with CR |
| UC5B |
| 1.0 |
| 20.0 |
| N/A |
| N/A |
*Creosote (CR) preservative is not allowed for bridge decks.
**For Glue laminated members Contractor must certify glue is compatible with treatment
2. Wood used for Hand-Contact Surfaces (including but not limited to handrails, playground equipment, and picnic tables shall be treated with the following non-arsenical, water-borne preserviatives per Table 2 below:
| Alkaline Copper Quat (ACQ) |
| Copper Azole (CA) |
| Micronized Copper Azole (MCA) |
Table 2 – Southern Yellow Pine Treatments & Retentions for Hand-Contact Surfaces per AWPA
| Commodity Specifications |
| Use Category |
| Preservative Retentions |
Waterborne (pcf)
| Designation |
| Wood Usage |
ACQ-A,B,C,D
CA-B
CA-C
MCA,
MCA-C **
| A |
| Sawn Products: |
UC4B
0.60
0.31
Boards, lumber and timber for picnic tables, handrails, playground equipment
| F |
| Wood Composites: |
UC4B
0.60
Plywood for picnic tables, handrails, playground equipment
** Note – ACQ, CA, MCA - Many wood treatments can be highly corrosive to metal under some conditions. Fasteners or connectors that will be in contact with wood using ACQ, CA, MCA wood preservative treatments shall be either 304 or 316 stainless steel or hot-dipped galvanized steel that conforms to ASTM A153 or ASTM A653, Class G185. The Engineer will not permit the use of mechanically galvanized steel hardware or fasteners with ACQ, CA, MCA treated wood. Wood treated with ACQ, CA, MCA shall be separated from steel or aluminum beams or posts using a non-metallic, rubber flashing.
Treatment shall conform to these additional requirements:
1. Waterborne preservatives shall be used for timber where a clean surface is desirable. The moisture content of wood material shall be not more than 19 percent at the time of treatment.
2. Oilborne preservatives (Pentachlorophenol, Creosote, Copper Naphthenate) may be used for timber that is not to be painted. Timbers treated with Pentachlorophenol, Creosote, or Copper Naphthenate shall be free of excess preservative on the wood surface. VDOT allows oilborne preservatives for special projects.
3. Field Cuts to Treated Wood - All cuts, pile cutoffs, bolt holes, field cuts and damage which penetrates the treated zone shall be protected in accordance with AWPA Standard M4. In cases in which the originally used preservative is not available for field use, copper naphthenate with minimum 2% copper metal shall be used. In all cases 3 heavy brushed applications of any preservative shall be used, with adequate penetration time between applications.
4. For any product not listed, refer to the latest AWPA, U1 Standard.
5. Treated timber shall be supplied only from facitities on Approved List # 45.
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