Minnesota Department of Transportation

511 Travel Info

Approved/Qualified Products

Treated wood

Table 1

MnDOT approved preservatives for the treatment of timber products1

Product and usage AWPA use category AWPA commodity specification U1
Section
AWPA commodity specification U1
Special Reqs.
MnDOT approved wood treatment (see Table 2 below)
A Piles
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
H Plywood
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.

Table 2

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
PTI

Non-metal pesticide treated wood.
Propiconazole
Tebuconazole

Imidacloprid
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
ESR-2240
AC 326
AWPA P61
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.