Lumber & Framing Guide
Lumber & Framing Guide
Framing is the skeleton of every structure. Picking the wrong grade, the wrong species, or the wrong moisture content leads to callbacks, sagging floors, and failed inspections. Here is what matters when you order lumber from Western Works.
Understanding Lumber Grades
Stud Grade (#2 & Better)
Standard for wall framing. Knots are tight and small. Suitable for load-bearing and non-load-bearing walls. Most common residential choice.
#2 Douglas Fir-Larch
Higher strength-to-weight ratio than SPF. Ideal for floor joists, rafters, and headers where span and load matter.
Kiln-Dried (KD19)
Dried to 19% moisture or less. Reduces warping, twisting, and shrinkage after install. Always specify KD for interior framing.
Pressure-Treated UC4A
Ground contact rated with MCA preservative. Required for fence posts, deck posts, and any wood touching soil or concrete.
Nominal vs Actual Size
A 2x4 is not actually 2 inches by 4 inches. It is 1-1/2 inches by 3-1/2 inches. A 4x4 post is 3-1/2 by 3-1/2. Always design your layouts around actual dimensions, especially when calculating insulation, sheathing, and finish materials.
Green lumber (non-kiln-dried) will shrink across the width as it dries. A wall framed with green studs can lose up to 1/2 inch in total width over the first heating season. Use KD lumber for all interior work.
Engineered Wood: When to Upgrade
Laminated Veneer Lumber (LVL) beams are stronger, straighter, and more consistent than solid sawn lumber. Use LVL for headers over garage doors, long floor beams, and any span where a solid beam would require a deeper member or mid-span support.
Quick Reference: LVL vs Solid Beam
- LVL: No knots, no splits, consistent strength, lighter weight, longer spans.
- Solid Beam: Lower cost, traditional appearance, acceptable for short spans and decorative use.
Sheathing and Subflooring
CDX plywood holds fasteners better than OSB and resists edge swelling during rain exposure. OSB Sturd-I-Floor with tongue and groove edges is the standard for subflooring and eliminates squeaks when installed with construction adhesive. For roof sheathing in high-wind zones, use plywood or ring-shank nails with OSB.