How do you pick good lumber at the store?

Use the six-point inspection: (1) sight down the edge for bow and twist, (2) check ends for cupping, (3) look for checks and splits along the grain, (4) evaluate knot tightness, (5) check for wane (bark/missing wood on edges), and (6) verify moisture content if possible. Dig through the stack — the best boards aren't always on top. Buy 10-15% extra to account for defects. What does KD mean on lumber?

What does KD mean on lumber?

KD stands for "kiln dried" — meaning the lumber was dried in a kiln to reduce moisture content to 12-19%. KD-HT means kiln dried and heat treated. Kiln-dried lumber is more stable, less likely to warp, and ready for indoor use. S-GRN (surfaced green) means the wood is still wet (over 19% MC) and will shrink as it dries — fine for framing but avoid for furniture. How much extra lumber should I buy?

How much extra lumber should I buy?

Buy 10-15% more lumber than your project requires. This accounts for defect removal (knots, end checks, wane that need to be cut away), cutting errors, and the waste from cross-cutting and ripping to final dimensions. For complex projects with many small parts, buy 15-20% extra. Unused lumber can usually be returned to the store.

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How to Choose Lumber at the Store: A Buyer's Checklist

Lumberama Editorial Team, Lumber Buying & Selection Specialists Jun 12, 2025 8 min read

Why Board Selection Matters

A home center lumber stack contains boards ranging from near-perfect to barely usable. The difference is often significant — some boards are flat, straight, and clear while others are twisted, cupped, and full of knots. Spending 10 extra minutes inspecting boards saves hours of fighting bad lumber in the shop.

The Six-Point Inspection

1. Sight down the edge (check for bow and twist): Pick up the board and look down its length from one end, like aiming a rifle. A bowed board curves like a banana. A twisted board winds like a propeller. Slight bow can be corrected with jointing; twist is harder to fix and wastes material. Reject boards with visible twist.

2. Check for cup: Look at the end of the board. Cupping is when the board curves across its width (the edges are higher than the center, or vice versa). Slight cupping in wide boards is normal and can be flattened on a jointer or with a planer. Severe cupping (more than 1/8" in a 6" board) wastes too much material.

3. Look for checks and splits: Checks are cracks along the grain that form as wood dries. End checks (at the board ends) are common and can be cut off. Face checks running along the length are more serious — they weaken the board and may continue to spread.

4. Evaluate knots: Tight knots (firmly attached to surrounding wood) are structural and can be attractive in rustic projects. Loose knots (dark rings around the knot, possibly falling out) are weak points that can create holes. For structural or finish work, choose clear boards or boards with only tight, small knots.

5. Check for wane: Wane is bark or missing wood on the edge of the board. It means the board was cut from near the outside of the log. Minor wane on one edge can be ripped off. Full wane on both edges means a narrower usable board than you're paying for.

6. Check moisture content: Kiln-dried lumber (KD stamp) should be at 12-19% moisture content. If you have a moisture meter (and serious woodworkers should), check several boards. Avoid boards significantly wetter than others in the stack — they'll move more as they continue to dry.

Reading Grade Stamps

KD or KD-HT: Kiln dried. KD-HT means kiln dried and heat treated (for pest control in international shipping). What you want for indoor projects.

S-DRY: Surfaced dry (less than 19% MC when surfaced). Standard for construction lumber.

S-GRN: Surfaced green (over 19% MC). Wet — will shrink, check, and warp as it dries. Avoid for furniture; acceptable for framing that will dry in place.

Grade marks: #1, #2, #3, Stud, Utility. #1 has the fewest defects. #2 is standard construction grade (most common at home centers). Premium/Select grades have fewer knots and straighter grain.

Stacking Strategy

Dig through the stack. The best boards are not on top (those get handled, knocked around, and exposed to sunlight). Work from the top of the stack but evaluate every board. Set rejected boards aside neatly (don't leave a mess).

Buy 10-15% extra. Even with careful selection, you'll lose material to end trimming, defect removal, and the occasional cutting mistake. Returning unused boards is easy; making a mid-project trip for one more board is annoying.

Group by quality. Sort your selected boards mentally: clear/straight boards for visible faces, lesser boards for hidden parts, cutoffs for short components.

Home Center vs Lumberyard

Home center pros: Convenient, immediate availability, no minimum purchase, easy returns. Good for construction lumber, pressure treated, and common softwood boards.

Home center cons: Limited species (usually just pine, common boards in oak and poplar). Quality is inconsistent. Boards may have been poorly stored. Staff typically can't help with wood selection.

Lumberyard pros: Dozens of species. Better quality control. Staff who know wood. Rough sawn options for better value. Professional-grade materials. Board-foot pricing (transparent).

Lumberyard cons: May have minimum purchase requirements. Cash/check sometimes required. Less convenient. Intimidating for beginners (but the staff is usually very helpful if you ask).