✓ The Decision — Which Lumber for Which Job
- Walls, plates, blocking → kiln-dried dimensional SPF. The default for a reason: cheap, predictable, code-mapped. Buy straight, store flat.
- Anything touching concrete, soil, or weather → pressure-treated. Sill plates, deck framing, posts. Non-negotiable, and use the hardware rated for it.
- Long spans, big openings, point loads → LVL or engineered. A garage-door header is LVL territory; don't try to stack enough 2×10s to fake it.
- Roofs → engineered trusses, almost always. ~60% less labour than stick framing, engineering included in the price. Stick-frame only for custom shapes or free labour.
- Floors over 12–14 ft spans → engineered I-joists beat dimensional on straightness, span, and squeak-resistance for modest premium.
Dimensional SPF: The Workhorse
Spruce-pine-fir is what Canadian framing is made of. In 2026 a 2×4×8 stud runs $4–$6 retail, with framing lumber wholesale around $870/MBF and still climbing modestly year over year. Two things matter more than brand:
- Kiln-dried (KD) vs green: KD framing lumber is dried to 19% moisture or less — it stays the size and shape you bought. Green lumber shrinks, twists, and checks as it dries in your wall. Nearly all framing stock at Canadian yards is KD; verify the stamp (S-DRY or KD) on anything from a mill or a deal pile.
- Grade: No.2&Btr is the standard framing grade and what span tables assume. "Stud" grade is fine for studs; don't put it in headers or joists.
- Pick your own: sight down every stick. A bunk of lumber contains its share of propellers, and the yard doesn't mind you sorting — culls cost you more in framing time than they save in price.
Pressure-Treated: Where Wood Meets Water
Modern Canadian PT is mostly copper azole (CA) or MCA-treated SPF. It belongs anywhere wood contacts concrete, soil, or weather — sill plates on your slab, deck structure, fence posts, ground-contact landscape work. Three practical notes: use hot-dip galvanized or stainless fasteners (treatment chemicals corrode ordinary steel — and yes, this is one more reason deck screws aren't structural screws); buy it as dry as you can find and expect some shrinkage anyway (KDAT — kiln-dried after treatment — is common in the U.S. but rare at Canadian yards); and check the treatment level tag: ground-contact rated where it touches soil, above-ground elsewhere.
LVL and Engineered Lumber: Bought Strength
Laminated veneer lumber is veneers glued into a beam that's straighter, stiffer, and far stronger than sawn lumber of the same size. Cost: roughly $3–$6 per linear foot for a 1¾"×9½", scaling up with depth — figure 3–5× a comparable 2×10. Where it earns that:
- Garage door headers and other long openings — our wall framing calculator prices these separately for exactly this reason.
- Beams carrying point loads from posts or girder trusses above.
- Flush beams in floors where a dropped beam won't do.
The catch: LVL sizing is an engineering call, not a guess. Suppliers size them free against your loads; your permit reviewer will want to see the spec. LVL also hates weather — keep it dry until it's enclosed.
Engineered Trusses: Labour in a Package
For roofs (and increasingly floors), trusses are bought engineering: a stamped design, less lumber than stick framing, and assembly measured in hours instead of days. Our roof framing guide covers the attic-space angle; the short version is that the truss plant quote is free and usually wins on total cost once labour is honest.
Quick Comparison
| Product | 2026 cost signal | Use it for | Don't use it for |
|---|---|---|---|
| KD dimensional SPF | $4–6 / 2×4×8 | Walls, plates, general framing | Long spans, wet locations |
| Pressure-treated | ~1.5–2× SPF | Sills, decks, ground contact | Interior framing (unneeded $) |
| LVL | $3–6+/lf | Headers, beams, point loads | Anywhere sawn lumber spans fine |
| I-joists | Modest premium | Long, straight, quiet floors | Exposed/wet applications |
| Engineered trusses | Per-design quote | Roofs, long floors | One-off custom shapes (maybe) |
Wall Framing Calculator
✗ Deal-Breakers — Material Mistakes That Cost Real Money
- Sawn lumber where engineering is required. A garage-door header of stacked 2×10s that the inspector rejects gets rebuilt at your cost — in the worst case, after the roof is on it.
- Untreated wood on concrete or soil. The sill plate rots first and takes the wall's bottom with it. PT or a sill gasket isolation — code says so for good reason.
- Ordinary fasteners in treated lumber. The treatment eats them. Galvanized or stainless, rated for PT contact, every time.
- Green or wet lumber enclosed in a finished wall. It will dry in place — and crack your drywall, bow your studs, and open your trim joints on the way.
The Safest Path Forward
- Frame the default: KD SPF for walls, PT for anything touching concrete or weather, and flag every span over ~10 ft for an engineered answer.
- Take off the package with the wall framing calculator — waste factor included.
- Get LVL and truss quotes from the supplier — sizing is free, stamped, and exactly what your permit reviewer wants to see.
- Sort your lumber at the yard and store it flat, covered, and off the ground on site.
- Match fasteners and hangers to the material — the connection schedule on your permit drawings is the final word.
Frequently Asked Questions
What's the difference between kiln-dried and green lumber?
Kiln-dried framing lumber is dried to 19% moisture or less, so it stays straight and stable in your wall. Green lumber shrinks and distorts as it dries in place. Virtually all framing stock at Canadian retailers is KD — check the grade stamp for S-DRY or KD.
How much does an LVL beam cost in Canada?
Roughly $3–$6 per linear foot for a 1¾"×9½" in 2026, rising with depth — about 3–5× the cost of a comparable 2×10. Supplier sizing is free; installed structural beam projects commonly run $500–$6,000 depending on size and location.
Can I use regular lumber for a garage door header?
Usually not for double-car widths — the spans and roof loads typically demand engineered lumber (LVL or similar). Your truss/beam supplier sizes it free, and your building permit will require the spec.
Do I really need pressure-treated for the sill plate?
Wood in contact with concrete needs protection — pressure-treated lumber or an approved sill gasket isolating it. Concrete wicks moisture, and untreated sills are where garages rot first.