Treated Wood End Use Guide
Ground Contact treated wood can be used in Above Ground applications.
Above Ground
1
High Level Deck Boards
2
Railings & Accessories
3
Fence Boards and Rails
4
Trellis
5
Lattice
Ground Contact
6
Ground Level Deck
7
Stair Stringers
8
Ledger Boards*
9
Post Supporters
10
Joists*
11
Beams*
12
Planter Boxes
13
Fence Posts
14
Retaining Walls
15
Playset Structures
16
Ground Level Walkway
17
Raised Garden Bed
18
Fresh Water Bulkhead
19
Fresh Water Dock
20
Fresh Water Dock Posts
21
Floating Dock (Decking, Joists, Beams)
When treated wood is used in an above ground application where the treated wood component would be considered difficult to maintain, repair or replace and that the component is critical to the performance and safety of the structure.
New AWPA Standards for Treated Wood
Effective July 2016, the American Wood Protection Association (AWPA) U1 Standard was revised establishing new guidelines for wood treated to UC4A Ground Contact General Use.
Ground Contact UC4A treated wood shall be used in situations that simulate ground contact conditions such as:
- Ground Level Decks and Walkways
- Treated wood when installed less than 6” above the ground.
- When treated wood is used in an application that does not permit air circulation or water drainage underneath the structure.
- When treated wood is used in an application where vegetation, leaf litter, or other debris can build up and remain in contact with the treated wood product.
- Decks and Fresh Water Docks
- When treated wood is used in an above ground application where the treated wood component is difficult to maintain, repair or replace and that component is critical to the performance and safety of the structure. This standard change affects joists and beams used in above ground decks and fresh water docks, including floating docks.
- When treated wood is wetted on a frequent or recurring basis such as wind and wave action (such as fresh water docks and walkways) or watering systems, swimming pools and hot tubs.
- Export Products - Exterior Use
- When treated wood is used in tropical climates.
Treated Wood Use Categories
| UC | Description |
|---|---|
| UC1 | Interior Dry |
| UC2 | Interior Damp |
| UC3A | Exterior Above Ground, Coated with Rapid Water Runoff |
| UC3B | Exterior Above Ground, Uncoated or Poor Water Runoff |
| UC4A | Ground Contact, General Use |
| UC4B | Ground Contact, Heavy Duty |
| UC4C | Ground Contact, Extreme Duty |
| UC5A | Marine Use, Northern Waters (Salt or Brackish Water) |
| UC5B | Marine Use, Central Waters (Salt or Brackish Water) |
| UC5C | Marine Use, Southern Waters (Salt or Brackish Water) |
| UCFA | Interior Above Ground Fire Protection |
| UCFB | Exterior Above Ground Fire Protection |
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