MnDOT approved preservatives for the treatment of timber products1
|Product and usage||AWPA use category||AWPA commodity specification U1
|AWPA commodity specification U1
|MnDOT approved wood treatment (see Table 2 below)|
|A1 – Round||UC4C2||E||-||PCP, CuN, CA-C|
|B Posts: Fence, Guide & Sight|
|B1 – Round||UC4A2||B||-||MCA, CuN, ACQ-D, CA-C|
|B2 – Sawn Four Sides||UC4A2||A||-||MCA, CuN, ACQ-D, CA-C|
|C Posts: Guardrail & Spacer Blocks, Noise|
|C1 – Round||UC4B2||B||-||MCA, ACQ-D, CA-C|
|C2 – Sawn Four Sides||UC4C2||A||Sub Sec 4.33||MCA, ACQ-D, CA-C|
|D Poles, Lighting|
|D1 – Round||UC4B2||D||-||MCA, CuN, CA-C|
|E Lumber and Timber|
|E1 – Bridges, Prefab (nail laminated) Panels, other Structural Members, Culverts and other uses||UC4C2||A||Sub Sec 4.33||PCP|
|E2 – Noise Wall Facing – at or below ground level||UC4B2||A||-||MCA, ACQ-D, CA-C|
|E3 – Building Construction or Repair – at or below ground level||UC4A2||A||-||MCA, CuN, ACQ-D, CA-C|
|E4 – Decks, porches, handicap ramps, boardwalks, or pedestrian bridge decking||UC4A2||A||-||PCP|
|F Lumber and Timber (not in contact with ground or water|
|F1 – Handrails, Sidewalk Plank||UC3B||A||-||PTI, MCA, ACQ-D, CA-C|
|F2 – Noise Wall Facing – above ground level||UC3B||A||-||PTI, MCA, ACQ-D, CA-C|
|F3 – Building Construction or Repair||UC3B||A||-||PTI, CuN, MCA, CA-C|
|F4 – Bridges, Prefab (nail laminated) panels, structural members, and other uses||UC4C2||A||Sub Sec 4.33||PCP|
|G Glue-Laminated Structural Members (treated after gluing)|
|G Glue-Laminated Structural Members (treated after gluing)||UC4B2||F||-||PCP, CuN|
|H1 – In contact with ground or water||UC4A2||F||-||MCA, ACQ-D, CA-C|
|H2 – For use above ground||UC3B||F||-||PTI, CuN, MCA, ACQ-D, CA-C|
1 MnDOT approved preservatives does not include the actual wood treated product. MnDOT functional offices approve the final treated wood product for use on specific MnDOT projects.
2 Products listed by the AWPA or approved by the International Code Council-Evaluation Service (ICC-ES) must submit documentation as proof of passing results from test method AWPA E7, substitution of test method AWPA E20 is not acceptable.
3 Sub section 4.3: Retreatment. Poles may be retreated provided none of the limitations is AWPA Standard T1 - "Use Category System: Processing and Treatment Standard," Section 6 (entitled "Retreatment") are exceeded.
Product definition and MnDOT use restriction of approved wood treatments
|Treatment||Definition||AWPA/ICC-ES Specification Requirements1||Standard AWPA Method for Determining Retention4||Use Restrictions|
Non-metal pesticide treated wood.
|AWPA P45||A28 (Azoles) or A31 (Azoles), A43 (Imidacloprid) or A48 (PTI)||Cannot use within 100 feet of surface water3. Structural members must not be in contact with soil.|
|CuN||Copper naphthenate||AWPA P36||A14 (Cu) or A84 (Cu) or A88 (Cu) or A9 (Cu X-ray spectroscopy)||Cannot use within 100 feet of surface water3. Cannot use within 100 feet of residential or recreational areas4.|
|PCP5||Non-aqueous pentachlorophenol||AWPA P35||A83 (Lime ignition) or A9 (Cu X-ray spectroscopy)||Non-aqueous pentachlorophenol wood products will be phased out of use as appropriate approved products with better environmental performance become available.|
|MCA||Micronized Copper Azole||ICC-ES
|A21 (Cu) or A61 (Cu) or A9 (Cu X-ray spectroscopy), A28 (Azoles) or A31 (Azoles)||Cannot use within 25 feet6 of surface water3. Fasteners must be in accordance with IBC 2304.10.5.|
|CA-C||Copper Azole Type C||AWPA P48||A9 (Cu) or A21 (Cu), A28 (Azoles) or A31 (Azoles)||Cannot use within 25 feet6 of surface water3. Fasteners must be in accordance with IBC 2304.10.5.|
|ACQ-D||Alkaline Copper Quaternary- Type D||AWPA P29||A9 (Cu) or A21 (Cu), A16 (Quat) or A17 (Quat) or A37 (Quat)||Cannot use within 25 feet6 of surface water3. Fasteners must be in accordance with IBC 2304.10.5.|
1 Specification requirements and appropriate methods for determining retention shall be in accordance with the most recent AWPA or ICC standard.
2 Penetration and other treatment requirements shall be in accordance with AWPA Standard T1 and the AWPA Use Category Standards listed in MnDOT Specifications Table 3491-1.
3 For purposes of this document, surface water is considered to be a permanent water such as, but not limited to; rivers, streams, creeks, lakes, or ponds (not including artificially constructed sediment ponds).
4 Residences are characterized by the single-family or multiple-family dwellings. Recreational areas are characterized by unrestricted access to the public and include, but are not limited to; parks, playing fields, beaches, green spaces, open areas, wildlife management areas, and nature preserves. Setback distance from recreational area should be determined from vicinity where people likely congregate (example: picnic or playground areas).
5 Unless otherwise specified, the pentachlorophenol solution for wood treatment shall consist of not less than 5.0 percent of pentachlorophenol in heavy petroleum solvent (AWPA A9, Type A).
6 An MCA, CA-C or ACQ-D noise wall or boardwalk should, at no point along the structure, be closer than 25 feet to a surface water shoreline (lake, reservoir, impoundment, or stream).
Building structures with MCA, CA-C or ACQ-D treated wood such as pole barns, storage sheds, garages, or out-houses should be no closer than 6 feet to a surface water shoreline. (Minnesota Department of Natural Resources setback distances from surface water may apply.)
Guard rail barriers or similar low wood mass structure constructed with MCA, CA-C or ACQ-D treated wood posts should be no closer than 3 feet to a surface water shoreline.