5/8 Inch Drywall Cost in 2026:
$18 to $24 Per Sheet (Type X Fire-Rated)
The thicker, fire-rated board required by code in specific locations. Per-sheet pricing, where it is mandatory, what Type X actually means in fire-resistance terms, and what the upgrade costs on a typical garage or party-wall project.
What 5/8 Inch Type X Drywall Is
5/8 inch Type X is the fire-rated variant of standard drywall. The "5/8 inch" refers to the panel thickness (versus the standard 1/2 inch). The "Type X" designation refers to a specific gypsum core formulation that includes glass fibers and other additives designed to resist heat and slow fire spread when the panel is exposed to flame.
A standard 5/8 inch Type X drywall assembly (a single layer of 5/8 inch Type X on each side of a wood-framed wall) provides one hour of fire resistance under ASTM E119 testing. That one-hour rating is the basis for the building-code requirements that drive Type X usage. Without the rating, a fire that starts on one side of the wall would burn through to the other side in 15 to 30 minutes. With Type X, the wall resists burn-through for at least 60 minutes, giving occupants time to escape and giving fire departments time to respond.
Type C is a related designation, enhanced with additional fire-resistive additives, that provides longer fire ratings (typically two hours in a similar single-layer assembly). Type C costs about $5 to $10 more per sheet than Type X but is rarely required in residential construction.
Where IRC R302 Requires 5/8 Inch Type X
The International Residential Code (IRC) section R302.6 is the primary source of 5/8 inch Type X requirements in residential construction. The relevant provisions:
- Garage walls adjacent to dwelling. 1/2 inch gypsum board minimum, with 1/2 inch Type X required on walls between a private garage and any habitable room above the garage. Most builders default to 5/8 inch Type X on these walls to standardise procurement and simplify framing inspections.
- Garage ceiling beneath habitable space. 5/8 inch Type X gypsum board minimum on the ceiling of an attached garage when there is habitable space above (a bonus room over the garage, for example). No exceptions.
- Structural supporting habitable space above garage. Walls supporting the floor or ceiling assembly above the garage require 1/2 inch gypsum board minimum on the garage side.
- Penetrations. The HVAC ducts, vents, or other penetrations through the garage-to-living-space wall must be fire-stopped per code, regardless of the wall drywall.
Beyond IRC R302.6, additional 5/8 inch Type X requirements come from local codes and other sections of the IRC and IBC. Party walls between townhouses (R302.2) typically require two-hour fire resistance, which means 5/8 inch Type X on each side plus other assembly details. Apartment corridors and unit-to-unit walls require similar ratings under IBC. Detailed code interpretation is on the IRC 2021 Chapter 3 code reference.
5/8 Inch Installed Cost on Typical Projects
The fire-rated upgrade adds about $0.25 per square foot to the installed cost over standard 1/2 inch. On the project sizes where 5/8 inch is most commonly required, the dollar impact is modest.
| Project | Drywall area | 1/2" installed | 5/8" Type X installed | Upgrade cost |
|---|---|---|---|---|
| Single garage wall (8x16 ft) | 128 sqft | $192 to $448 | $224 to $480 | +$32 |
| 2-car garage ceiling (20x22 ft) | 440 sqft | $660 to $1,540 | $770 to $1,650 | +$110 |
| Townhouse party wall (8x40 ft each side) | 640 sqft | $960 to $2,240 | $1,120 to $2,400 | +$160 |
| Apartment unit (full 5/8 throughout, 1,200 sqft floor) | 3,600 sqft | $5,400 to $12,600 | $6,300 to $13,500 | +$900 |
The upgrade cost is modest in absolute terms. The reason contractors quote 5/8 inch when 1/2 inch would suffice is not margin but standardisation: it is faster to order one type of board for a job than to mix specs across rooms.
Installation Differences: Heavier Board, Tighter Screw Pattern
5/8 inch Type X drywall is significantly heavier than standard 1/2 inch. A 4x8 sheet of 5/8 inch Type X weighs 71 pounds, versus 54 pounds for regular 1/2 inch. On a 35-sheet job (typical garage with ceiling), the total weight of the boards is 2,485 pounds versus 1,890 pounds for 1/2 inch. Stocking labour increases proportionally, and DIY installers should be aware that solo hanging is much more difficult with 5/8 inch.
Ceiling hanging in particular requires either two people or a drywall lift (jack). A single person can hang 1/2 inch on a ceiling with a t-brace and luck. 5/8 inch on a ceiling is a two-person job or a lift-rental job, no shortcuts.
Screw pattern is the same as 1/2 inch (every 16 inches on walls, every 12 inches on ceilings, screws sunk just below paper surface without breaking the paper). Use 1-5/8 inch or 2 inch coarse-thread drywall screws to ensure adequate penetration into the framing. Standard 1-1/4 inch screws used for 1/2 inch will not penetrate framing deeply enough with 5/8 inch board, and will pull out under load.
5/8 Inch for Non-Fire Applications (Ceiling Sag Resistance, Acoustic)
Beyond code-mandated fire-rated applications, 5/8 inch drywall has two voluntary use cases worth considering. First, sag resistance on ceilings. A 1/2 inch drywall ceiling spanning 24-inch joists will sag over time, particularly in humid conditions. 5/8 inch drywall (or specialty "sag-resistant" 1/2 inch board marketed as ceiling board) prevents the sag. If you have engineered floor joists at 19.2 or 24 inch spacing, upgrade to 5/8 inch on ceilings.
Second, sound transmission reduction. 5/8 inch drywall blocks more sound than 1/2 inch, particularly in the lower frequencies. The Sound Transmission Class (STC) of a single-layer 1/2 inch drywall partition is around 33; the same partition with 5/8 inch reaches STC 35 to 37. The difference is modest but noticeable, particularly between bedrooms and shared walls. For dedicated home theatres or music rooms, specialty soundproof drywall is a better choice, see soundproof drywall cost.
Third (rare in residential, common in commercial), wall durability. 5/8 inch drywall resists impact damage and screw pull-out better than 1/2 inch. Hospitals, schools, and high-traffic commercial spaces sometimes specify 5/8 inch throughout for this reason. For a typical residence, the durability gain over 1/2 inch is real but small.
Frequently Asked Questions
Is 5/8 inch Type X required in all garages?
Required on the ceiling of garages with habitable space above. Required on walls between garage and habitable rooms (1/2 inch Type X minimum, with 5/8 inch Type X commonly used for standardisation). Not required in detached garages or storage-only garages.
Can I use regular 5/8 inch instead of Type X?
Regular 5/8 inch is not commonly produced. Most 5/8 inch drywall sold at home centres is Type X by default because the fire-rated applications drive the market. If you see 5/8 inch board, assume Type X unless explicitly labeled otherwise.
How much does the upgrade cost on a typical garage?
About $100 to $150 for a 2-car garage upgrade from 1/2 inch to 5/8 inch Type X. Material cost difference is $5 to $9 per sheet, labour cost difference is minimal. The total is small relative to overall garage drywall budget.
Does 5/8 inch drywall need a thicker screw?
Yes. Use 1-5/8 inch or 2 inch drywall screws instead of the 1-1/4 inch screws used for 1/2 inch. The extra screw length ensures adequate framing penetration through the thicker board.
Can I mix 5/8 inch and 1/2 inch on the same job?
Yes, and contractors commonly do this. Garage walls and ceilings get 5/8 inch Type X where required. Adjacent interior walls and unrelated rooms get 1/2 inch standard. The procurement complexity is minimal because both products are stocked at every lumberyard.