# Drywall Thickness and Types: Which Panel Goes Where Drywall thicknesses and types compared from manufacturer data: uses, weights, ceiling spacing, Type X, and moisture-resistant board. Guide page: (published 2026-10-06, updated 2026-10-06). This Markdown version has the guide's key points, outline, FAQs and sources; the full article, with its worked examples and diagrams, is on the page. ## Key takeaways - USG makes Sheetrock panels in 1/4, 3/8, 1/2, and 5/8 in. It says 1/4 in should never be hung as a single layer, and rates its 1/2 in UltraLight for walls and ceilings framed up to 24 in on center. - Type X is fire-resistant board for rated walls and ceilings. The rating belongs to the tested assembly, and not every 5/8 in panel is Type X. - IRC Table R302.6, as quoted by Gig Harbor, WA, calls for at least 1/2 in gypsum board on the garage side of the walls to the house and attic, and 5/8 in Type X under habitable rooms above the garage. - Moisture- and mold-resistant (green-faced) board resists moisture and mold, but USG says it is not a tile backer in tubs and showers. - Panel type doesn't change how many sheets you need, but it changes the weight: 1.25 lb/sq ft for 1/2 in UltraLight versus 2.2 for 5/8 in Firecode X. ## In this guide 1. [Drywall thicknesses at a glance](https://www.howmanyyardsdoineed.com/guides/drywall-thickness-and-types/#thickness-at-a-glance) 2. [Lightweight, moisture-resistant, Type X, and flexible panels](https://www.howmanyyardsdoineed.com/guides/drywall-thickness-and-types/#drywall-types) 3. [Ceilings and framing spacing](https://www.howmanyyardsdoineed.com/guides/drywall-thickness-and-types/#ceilings-and-framing) 4. [Garages and fire separation](https://www.howmanyyardsdoineed.com/guides/drywall-thickness-and-types/#garages-and-fire-separation) 5. [Sheet sizes and lengths](https://www.howmanyyardsdoineed.com/guides/drywall-thickness-and-types/#sheet-sizes) 6. [Worked example: sheets and weight by panel type](https://www.howmanyyardsdoineed.com/guides/drywall-thickness-and-types/#worked-example) 7. [Choosing panels: a checklist](https://www.howmanyyardsdoineed.com/guides/drywall-thickness-and-types/#choosing-panels) ## Frequently asked questions ### What thickness of drywall should I use for walls? USG rates its 1/2 in UltraLight and 5/8 in Firecode X panels for walls framed up to 24 in on center, and its 3/8 in panel for walls up to 16 in. It says 1/4 in should never be a single layer. Where a wall must be fire-rated, use the panel its rated design calls for, and follow your plans and local code. ### What thickness of drywall is best for ceilings? On joists 24 in apart, USG rates 1/2 in UltraLight in either direction, and 1/2 in Mold Tough and 5/8 in Firecode X only with the long edges across the joists. Its 3/8 in panel is limited to 16 in, across the joists, and not where the board carries insulation. Textured ceilings have tighter limits. ### Is 5/8 drywall the same as Type X? Not always. Type X is a fire-resistant board defined in ASTM C1396, and USG's Sheetrock Firecode X is a 5/8 in Type X panel. But USG's EcoSmart Firecode 30 is a 5/8 in panel that its submittal says is not a Type X panel, made for places where Type X is not required. Check the UL type printed along the panel's long edge. ### Can I use green board in a shower? Not as the tile backer. USG says its moisture- and mold-resistant UltraLight Mold Tough panels are not suitable as a tile substrate in wet areas such as tubs and showers, and can back tile only in dry areas or areas with limited water exposure. ### How much does a sheet of drywall weigh? Multiply the sheet's area by the maker's nominal weight. With USG's figures, a 4 × 8 ft sheet of 1/2 in UltraLight is about 40 lb, 1/2 in Mold Tough about 43 lb, and 5/8 in Firecode X about 70 lb; a 4 × 12 ft Firecode X sheet is about 106 lb. USG calls these approximate weights. ## Related calculators and guides ### Calculators - [Drywall Calculator](https://www.howmanyyardsdoineed.com/drywall-calculator/) — Drywall sheet count for walls and ceilings from room dimensions or total area, minus openings, by sheet size. - [Square Footage Calculator](https://www.howmanyyardsdoineed.com/square-footage-calculator/) — Total area in square feet, square meters, square yards, and acres from rectangles, triangles, circles, and trapezoids, minus cut-outs. ### Guides - [How to Measure a Room for Paint and Drywall](https://www.howmanyyardsdoineed.com/guides/how-to-measure-a-room-for-paint-and-drywall/) — Measure each wall and ceiling, subtract openings, handle gables, slopes, and stairwells, and keep it all on one sheet. - [How Many Coats of Paint Do You Need?](https://www.howmanyyardsdoineed.com/guides/how-many-coats-of-paint/) — Coats and primer by situation from paint makers' data sheets, recoat times, and how each coat changes the gallons to buy. - [How to Measure an Irregular Area](https://www.howmanyyardsdoineed.com/guides/measuring-irregular-areas/) — Split odd shapes into rectangles, triangles, circles, and trapezoids, then average width and depth. ### Buying guides - [Best Drywall Screw Guns (2026)](https://www.howmanyyardsdoineed.com/best/drywall-screw-guns/) — Cordless and corded drywall screw guns ranked on published specs for hanging drywall, with the screws for a room worked out from USG's fastener table. - [DEWALT vs Milwaukee Drill/Driver Kits Compared (2026)](https://www.howmanyyardsdoineed.com/best/dewalt-vs-milwaukee-drill-driver-kits/) — Seven 20V MAX and M18 drill/driver kits side by side on their makers' published specs, ranked for deck, drywall and fence work, with screw counts per job. ## Sources - [USG Sheetrock Brand Gypsum Panels (1/4 in and 3/8 in) submittal sheet (WB1473)](https://www.usg.com/content/dam/USG/pdpmovedocuments/sheetrock-gypsum-panels-regular-submittal-WB1473.pdf) — USG Corporation. Used for: 4 ft × 8–16 ft; nominal 1.2 lb/sq ft (1/4 in) and 1.4 lb/sq ft (3/8 in); single layer: 1/4 in not recommended, 3/8 in up to 16 in OC (ceilings perpendicular only). Checked 2026-10-06. - [USG Sheetrock Brand Flexible Gypsum Panels submittal sheet (WB2128)](https://www.usg.com/content/dam/USG/pdpmovedocuments/sheetrock-gypsum-panels-quarter-inch-flexible-submittal-WB2128.pdf) — USG Corporation. Used for: 4 ft × 8–12 ft; nominal 1.2 lb/sq ft; not for single-layer walls or ceilings. Checked 2026-10-06. - [USG Sheetrock Brand UltraLight Panels submittal sheet (WB2501): weight, uses, and framing spacing](https://www.usg.com/content/dam/USG/pdpmovedocuments/sheetrock-ultralight-panels-submittal-en-wb2501.pdf) — USG Corporation. Used for: 4 ft or 54 in × 8–16 ft; nominal 1.25 lb/sq ft; walls and ceilings up to 24 in OC in either direction; non-fire-rated. Checked 2026-10-06. - [USG Sheetrock Brand UltraLight Panels Mold Tough submittal sheet (WB2660)](https://www.usg.com/content/dam/USG/pdpmovedocuments/sheetrock-ultralight-mold-tough-panels-submittal-en-WB2660.pdf) — USG Corporation. Used for: 4 ft × 8–12 ft; nominal 1.35 lb/sq ft; ceilings 24 in OC perpendicular, 16 in parallel; water absorption ≤ 5% after 2 h; not a tile substrate in tubs and showers. Checked 2026-10-06. - [USG Sheetrock Brand Firecode X Panels submittal sheet (WB2964)](https://www.usg.com/content/dam/USG/pdpmovedocuments/usg-sheetrock-firecode-x-panels-submittal-en-usa-WB2964.pdf) — USG Corporation. Used for: 4 ft or 54 in × 8–16 ft; nominal 2.2 lb/sq ft; ceilings 24 in OC perpendicular, 16 in parallel; walls 24 in. Checked 2026-10-06. - [Important Fire Safety Information: 5/8" Type X Gypsum Wallboard](https://www.usg.com/content/dam/USG/pdpmovedocuments/type-x-gypsum-wallboard-fire-safety-information-en.pdf) — USG Corporation. Used for: Type X: not less than one-hour fire resistance when tested in specified assemblies. Checked 2026-10-06. - [USG Sheetrock Brand Installation and Finishing Guide (J371, rev. 9-15)](https://www.usg.com/content/dam/USG/pdpmovedocuments/sheetrock-gypsum-panels-installation-guide-en-J371.pdf) — USG Corporation. Used for: Four thicknesses (5/8, 1/2, 3/8, 1/4 in); 1/4 in never as a single layer; 12 ft panels hung horizontally minimize joints. Checked 2026-10-06. - [USG Sheetrock Brand EcoSmart Panels Firecode 30 submittal sheet (WB2858)](https://www.usg.com/content/dam/USG/pdpmovedocuments/usg-sheetrock-ecosmart-panels-firecode-30-submittal-en-usa-WB2858.pdf) — USG Corporation. Used for: 5/8 in; not an ASTM C1396 Type X panel; for applications where 5/8 in Type X is not required. Checked 2026-10-06. - [Client Assistance Memo: Residential Garage Separation (2015 IRC Table R302.6)](https://gigharborwa.gov/DocumentCenter/View/1880/Residential-Garage-Separation---Client-Assist-Memo) — City of Gig Harbor, Washington. Used for: At least 1/2 in gypsum board on the garage side; at least 5/8 in Type X under habitable rooms above the garage. Checked 2026-10-06. **Estimate only.** Results are planning estimates computed from the numbers you enter. They are not engineering, structural, or code advice. Confirm quantities, product yields, and installation requirements with your supplier, the product label, and your local building authority before you order or build.