Drywall spec guide: thickness, type and sheet size

Thickness: the common sizes and where they typically go

Gypsum board is sold by thickness. The sizes below are the typical North American conventions — confirm the exact requirement for your assembly and local code rather than treating this list as a design rule.

• 1/4 inch — typically used for curved surfaces and as a skim layer over existing board
• 3/8 inch — light-duty applications and some repair work
• 1/2 inch — the common default for standard residential walls and ceilings
• 5/8 inch — heavier duty: commercial work, ceilings needing more sag resistance, and the usual thickness for fire-resistance-rated assemblies

Regular vs Type X is a fire-performance difference

Regular gypsum board has a standard gypsum core. Type X board has a specially formulated, glass-fiber-reinforced core designed for fire-resistance-rated assemblies — it is the board typically specified where a fire rating is required, commonly in 5/8-inch thickness. Type X is not “thicker regular board”, and regular board is not a substitute in a rated assembly. Related variants you may encounter include moisture- and mold-resistant boards and abuse-resistant boards; each is its own spec, not an upgrade path you can assume.

Sheet sizes

The standard sheet is 4 feet wide; lengths are typically 8, 10 or 12 feet, and some boards come in wider formats. Sheet length changes handling, waste and seam layout — a campaign or order that mixes lengths without saying so is mixing different line items.

Why spec snapshots matter for group aggregation

A group buy aggregates demand only when every buyer wants the identical board: same thickness, same type, same sheet size, same brand where the brand is specified. That identity is what lets a supplier price one ladder for everyone. This is why Buildzz snapshots the full spec onto a campaign — for example, a campaign for 5/8-inch Type X board aggregates only 5/8-inch Type X demand. The moment a buyer’s board differs, it belongs in a different campaign, and blending the quantities would produce a price for a product nobody actually ordered.

• State thickness, type (regular / Type X / other named variant), sheet width and length on every line
• State brand or manufacturer where the spec requires it — and say so explicitly where any brand is acceptable
• Keep edge profile (typically tapered) and any moisture/abuse rating as separate stated fields