Rough vs. Surfaced Lumber: S2S, S4S and SL1E Explained
Hardwood price lists use a set of abbreviations for how much milling a board has had. Picking the right one affects price, how much wood you lose, and how much work you do yourself.
The abbreviations
| Code | Meaning | What you get |
|---|---|---|
| RGH | Rough | Straight from the sawmill, dried but not planed. Fuzzy, saw-marked faces. |
| S2S | Surfaced two sides | Both faces planed to a consistent thickness. Edges still rough. |
| S3S | Surfaced three sides | Both faces plus one edge planed. |
| S4S | Surfaced four sides | Both faces and both edges planed. Ready to cut to length. |
| SL1E / SLR1E | Straight-line ripped one edge | One edge sawn straight on a gang rip saw, so you have a reference edge. |
| S2S/SL1E | Both | The most common “ready to use” hardwood for shops with a table saw. |
How much thickness you lose
Planing a rough board removes about 1/16”–3/32” per face. Standard surfaced 4/4 is about 13/16”, and 8/4 is about 1¾”. See the full table in what 4/4, 5/4 and 8/4 mean.
You still pay for board feet on the rough thickness, so 4/4 is billed as 1” whether you buy it rough or surfaced.
Rough lumber: pros and cons
Pros
- Usually cheaper per board foot
- You choose the final thickness, which matters when you want a full ⅞” or a thicker resawn piece
- You can flatten cupped or twisted boards properly before thicknessing, instead of inheriting the mill’s warp
Cons
- You need a jointer and planer (or a planer sled) to flatten and thickness it
- More waste: plan on 20–30% for rough stock versus 10–15% for surfaced
- Hard to judge color and figure through the rough surface. Bring a block plane or ask if you can plane a test patch.
Surfaced lumber: pros and cons
Pros
- Ready to cut with a table saw and miter saw
- Easy to see grain, color and defects at the yard
Cons
- Costs more per board foot
- Fixed thickness, usually ¾” from 4/4
- A board surfaced while cupped stays cupped. Surfacing makes boards smooth, not necessarily flat.
Which should you buy?
- No jointer or planer: buy S4S, or S2S/SL1E if you have a table saw to rip the second edge.
- Jointer and planer: buy rough for the best price and control.
- Mixed: S2S lets you skip the planer. Joint one edge and rip the other.
Estimate what to buy
Enter your parts in the board foot calculator, choose a higher waste allowance for rough stock, and print the list for the yard. For grade choices, see hardwood lumber grades explained.