NASCLA Accredited Commercial General ContractorWoodMedium
A contractor is evaluating wood framing lumber for a new commercial building. The lumber is marked with 'S-DRY'. What does this designation indicate about the wood?
- AThe lumber has been treated for insect and decay resistance.
- BThe lumber has been surfaced dry, meaning it was planed after drying.
- CThe lumber is suitable for structural applications only, not for finishes.
- DThe lumber has been air-dried to a moisture content (MC) of 19% or less.
Show answer & explanationAnswer & explanation
Correct answer: B. The lumber has been surfaced dry, meaning it was planed after drying.
The 'S-DRY' designation on lumber indicates that the wood was surfaced (planed) after it was dried to a moisture content of 19% or less. This ensures consistent dimensions and a smoother finish.
Why the other options are wrong
- A. Treatment for insects and decay is indicated by other stamps (e.g., 'CCA', 'ACQ').
- C. Lumber can be used for various applications; this stamp refers to its moisture content and surfacing.
- D. While the lumber is dried to 19% MC or less, 'S-DRY' specifically refers to the surfacing process after drying, not just the drying itself.
Lumber Moisture Content & Surfacing Stamps
Stamps on lumber indicating its moisture content at the time of surfacing (planing) and its resulting dimensional stability.
- S-DRY means Surfaced Dry (19% MC or less).
- S-GRN means Surfaced Green (over 19% MC).
- MC15 means Moisture Content 15% or less.
Memory trick: Stamps tell the story, dry or green, surfaced or rough, for all to be seen.