Construction & Hardware Reference

Construction Reference Lookup Workflow

Construction reference lookups follow a natural sequence: start with structural sizing (lumber dimensions and span tables), then move to fastener selection, and finally to materials specifications (concrete, mortar, pipe). Having the right numbers before you cut saves material and prevents failures.

Lumber Dimensions: Nominal vs Actual

A critical source of confusion in framing is the gap between nominal and actual lumber dimensions. A 2×4 is actually 1.5" × 3.5". A 2×6 is 1.5" × 5.5". A 2×8 is 1.5" × 7.25". A 4×4 post is actually 3.5" × 3.5". These actual dimensions matter for tight fits, calculating quantities, and structural calculations. The Lumber Dimensions Chart shows all standard nominal-to-actual conversions. Use actual dimensions in calculations, nominal dimensions when ordering.

Span Tables: Joists and Rafters

Span tables tell you the maximum span for a given lumber size, species, grade, and load. For a 16" on-center floor with 40 psf live load + 10 psf dead load (standard residential), a 2×8 Southern Yellow Pine No. 2 can span about 13'3". Increasing to a 2×10 extends the span to about 16'6" with the same lumber. The Joist Span Table covers floor joists and the Lumber Span Table covers general structural applications including rafters and headers.

Fastener Sizing: Nails, Screws, Bolts

Nail sizing uses the penny system: 16d nails (3.5" long, 0.162" diameter) are standard for wall framing and joist hangers. 8d nails (2.5") are used for sheathing and toe-nailing. 12d (3.25") for rim joists. Always use galvanized or ACQ-compatible fasteners for treated lumber. The Nail Size Chart maps penny sizes to dimensions and uses. The Screw Size Chart covers wood screws, drywall screws, and structural screws by diameter and thread count. For bolted connections, the Bolt Torque Chart gives torque specs by bolt grade and diameter. The Tap Drill Size Chart and Drill Bit Size Chart ensure correct pilot hole sizing before threading or fastening.

Concrete and Masonry Mix Ratios

Standard concrete mix ratios by volume: general purpose 1:2:3 (cement:sand:gravel), structural 1:1.5:3, high-strength 1:1:2. Water-to-cement ratio is critical — a w/c ratio of 0.45-0.55 gives good workability and strength for most applications. The Concrete Mix Ratios Guide gives proportions for 8 application types. The Concrete Cure Time Chart shows when you can form-strip, load, and traffic fresh concrete at different temperatures. The Mortar Mix Ratio Guide covers masonry mortars by type (M, S, N, O). The Plywood Grades Reference decodes the APA grading stamps for OSB and plywood panels.

Pipe and Conduit Sizing

Pipe sizing differs by material and use. For residential plumbing, ½" PEX serves most branch lines; ¾" serves main trunk lines; 1" for water heaters and high-flow applications. The PEX Tubing Size Chart shows OD, ID, and flow rates. Pipe threads have specific pitch and taper — NPT (National Pipe Taper) is standard in the US. The Pipe Thread Size Chart gives thread dimensions for every pipe size from ⅛" to 6". The Conduit Size Chart covers EMT, IMC, and rigid conduit fill percentages for different wire counts and gauges. The Rebar Size Chart maps bar numbers (#3 through #18) to diameter and weight for structural concrete. The Sheet Metal Gauge Chart shows gauge-to-thickness conversions for steel, aluminum, and stainless steel.

The Header Size Chart

Headers above doors and windows carry loads from above to the surrounding wall structure. For a 3-foot opening in a load-bearing wall, a double 2×8 header (with 1/2" plywood spacer to match wall thickness) handles 2-story loads. The Header Size Chart gives recommended sizes for different span widths and stories of load, so you can size headers correctly without consulting a structural engineer for standard residential applications.