Common Building Materials Reference
Why this matters
Every service trade encounters framing, drywall, plywood, insulation, exterior cladding. The tech who recognizes materials + understands the structure works around them safely + correctly. This is the field card.
Lumber sizes (nominal vs actual)
Nominal = name; actual = real dimension after milling.
1×2 (3/4 × 1-1/2 furring); 1×3 (3/4 × 2-1/2 lath); 1×4 (3/4 × 3-1/2 sub-trim); 1×6 (3/4 × 5-1/2 boards); 1×8 (3/4 × 7-1/4); 1×12 (3/4 × 11-1/4 shelving); 2×4 (1-1/2 × 3-1/2 studs); 2×6 (1-1/2 × 5-1/2 exterior R-19); 2×8 (1-1/2 × 7-1/4 floor/roof); 2×10 (1-1/2 × 9-1/4 longer spans); 2×12 (1-1/2 × 11-1/4 beams); 4×4 (3-1/2 × 3-1/2 posts). Standard lengths 8, 10, 12, 14, 16 ft; special 20, 24 ft.
Lumber grades
Construction grade: standard framing; SPF (spruce-pine-fir).
Standard + better (Stud grade): studs specifically.
#2 + Better: visible OR finish work.
#1 + Better: appearance grade; few knots.
Select: best appearance.
Pressure-treated (PT): green/brown stain; ACQ OR CCA copper preservative. ACQ-treated since 2004 (CCA banned residential 2003).
Cedar / redwood: natural rot resistance; trim + exterior.
Engineered lumber
LVL (laminated veneer lumber): thin layers of wood + adhesive; beams, headers; stronger + straighter than solid lumber.
Glulam (glued laminated): similar but larger glued layers; structural beams.
PSL (parallel strand): long strands + adhesive; high-strength beams.
I-joist: I-beam shape; deep web + flange; floor joists; stronger + lighter than solid lumber.
LSL (laminated strand): short strands; medium-strength.
Engineered wood I-joist (TJI): trade name; common floor framing.
Plywood
Sheathing (exterior wall, roof): 4 × 8 sheets; 1/4", 3/8", 1/2", 5/8", 3/4".
OSB (oriented strand board): 4 × 8 sheets; replaces plywood in much modern construction; cheaper + similar strength.
Underlayment (1/4" plywood): smooth surface under flooring.
Marine plywood: water-resistant adhesive + face; boats, exterior.
MDF (medium-density fiberboard): smooth + paintable; cabinet + trim; very heavy.
Particleboard: cheap; sub-flooring + cabinet; not for moisture.
Wafer board: similar to OSB; older.
Drywall
1/2" standard: most common interior wall + ceiling.
5/8" Type X (fire-rated): required between garage + house, around furnace OR water heater, garage ceiling under living area.
1/4" flexible: curves; lining.
Moisture-resistant (green board): bath + kitchen wet zones; behind tile.
Cement board (Durock, Hardibacker): tile substrate in wet area (shower, tub).
Mold-resistant (purple board): high-moisture areas; mold inhibitor in paper face.
Sheet sizes: 4 × 8, 4 × 9, 4 × 10, 4 × 12 (industry-standard).
Insulation
Fiberglass batt: pink (Owens Corning) OR yellow (Johns Manville); R-13 to R-30 typical; cheap; itchy + skin irritant.
Mineral wool (Roxul, Rockwool): better fire resistance; some sound dampening; itchy.
Cellulose: recycled paper; blown OR dense-pack; mold-treated.
Spray foam (open + closed cell): blown polyurethane; air seal + insulation in one; expensive.
Rigid foam (XPS pink, polyiso, EPS): foundation + sheathing; R-5 per inch.
Sheep's wool: natural; expensive; specialty.
Vapor barrier / vapor retarder: poly sheeting OR kraft-faced batt; varies by climate.
Roofing materials
Asphalt shingle (3-tab + architectural): most common residential.
Wood shake / shingle: cedar; high-end + traditional.
Tile (clay, concrete): heavy; needs reinforced framing; Southwest + Spanish.
Slate: premium; very long life; very heavy.
Metal (standing seam, corrugated): durable; rising popularity.
Modified bitumen / TPO / EPDM: flat OR low-slope roof.
Underlayment: felt OR synthetic; under shingles.
Ice + water shield: bituminous membrane at eaves OR valley.
Siding
Vinyl: most common residential; low cost.
Fiber cement (Hardie): durable; paint-receptive; rising popularity.
Wood (cedar lap, T1-11 plywood): traditional; high maintenance.
Stucco: 3-coat OR EIFS (synthetic).
Brick veneer: structural OR decorative.
Stone: high-end.
Aluminum: older; some commercial.
Concrete + masonry
Concrete mix: portland cement + aggregate + water; cures in 28 days to full strength.
Mortar: cement + lime + sand; for laying brick OR block.
Grout: thinner mortar; for filling joints (tile + masonry).
Concrete block (CMU - 8x8x16): foundations, retaining walls.
Brick: standard 4 × 8 × 2.25 ", varieties.
Stone: cut OR rubble.
Rebar: reinforcing steel for concrete; #4 (1/2"), #5 (5/8"), #6 (3/4") common residential.
Common service-trade interactions
HVAC: framing 2×6 walls allow R-19 batt + ducted insulation; basement / crawl space conditioned space affects calculations.
Plumbing: 2×4 walls (interior) tight for vent stacks; 2×6 walls (exterior) accommodate larger DWV better.
Electrical: drilling through studs (NEC 300.4 protections); not drilling through joists weakening structure.
Roofing: identifying decking material under shingles (plywood OR OSB; condition affects warranty).
Painting: drywall (latex; primer for new); wood (oil OR latex; primer for stain blockage).
Common building material mistakes
Drilling through structural OR notching beyond NEC / IRC limits (weakens). Mistaking OSB for plywood (both perform similarly for sheathing; differ for outdoor exposure). Mixing PT with regular fasteners (corrosion within 1 yr; HDG OR stainless required). Using regular drywall where Type X required (code violation). Skipping vapor barrier in cold climates. Insulation in wrong orientation (kraft face wrong side).
Truck stock (general repair work)
Drywall screws (1-1/4", 2"), drywall tape + mud (1 qt joint compound), assorted lumber scraps (2×4 scraps), screws + nails assortment, caulk (latex + silicone), insulation roll (1 batt), poly sheeting roll.
Identifying old materials (potential hazards)
Asbestos: insulation around old pipes (white covering), some floor tile (9×9), some siding (transite), older drywall mud + tape. PRE-1980 = test before disturbing.
Lead paint: pre-1978 homes. Test before sanding OR disturbing.
PCBs (polychlorinated biphenyls): old fluorescent ballasts, transformer oil, caulk.
Knob + tube wiring: pre-1940; insurance + code issues.
Code requirements
Fire separation: 5/8" Type X drywall between garage + house (NEC + IRC).
Egress windows: sleeping rooms below 4th floor.
Insulation R-values: per climate zone (IECC).
Stair specifications: tread + riser limits (IRC R311).
Handrail + guardrail: per IRC.
Customer-visible materials education
References
- IRC Chapter 5 + 6 (wood frame construction)
- AWPA U1 (treated wood standards)
- ASTM C36 (drywall standards)
- APA (Engineered Wood Association)
- Manuall internal: Common Codes Overview, PPE Selection