The following is from the American Society of Civil Engineers (ASCE)
MINOR DAMAGE:
- Checks (cracks) Splits, and gouges less than ½-inch wide; or
- Evidence of marine borers or fungal decay.
Minor damage reverts to the next highest rating if you see:
- Loss of cross section;
- Marine borer infestation; or
- Displacement, loss of bearing, or failed connections.
MODERATE DAMAGE
- Remaining diameter loss up to 15%;
- Checks and splits wider than 1/20-inch;
- Cross section area loss up to 25%; or
- Evidence of marine borers or fungal decay, with loss of section.
Moderate damage reverts to the next highest rating if you see:
- Displacement, loss of bearing, or failed connections.
MAJOR DAMAGE
- Remaining diameter loss 15% - 30%;
- Checks and splits through full depth of cross section;
- Cross section loss 25% - 50%;
- Heavily corroded hardware; or
- Displacement and misalignment at connections.
Moderate damage reverts to the next highest rating if you see:
- Partial or complete breakage.
SEVERE DAMAGE
- Remaining diameter less than 30%;
- Loss of connections and/or fully non-bearing condition;
- Partial or complete breakage