Type X drywall is a special fire‑resistant gypsum board designed to slow the spread of fire and help wall or ceiling assemblies achieve a rated fire- resistance period (often 1 hour or more, depending on the assembly).

Quick Scoop

What is Type X drywall?

  • Type X is a gypsum drywall panel formulated specifically for fire‑resistive construction.
  • It has a special core with noncombustible glass fibers and other additives that help it stay intact longer when exposed to high heat and flames.
  • In typical wall assemblies, 5/8‑inch Type X drywall on each side of wood studs can provide a 1‑hour fire rating when installed to tested standards.
  • It is commonly required by building codes in areas like attached garages, stairwells, corridors, shafts, and separation walls between dwelling units.

Key features

  • Fire‑resistant core (gypsum + glass fibers + special additives).
  • Usually thicker than standard interior drywall (commonly 5/8 inch).
  • Designed and tested to meet standards such as ASTM C1396 and used in assemblies rated for up to 4 hours, depending on configuration and product.
  • Installs similarly to regular drywall (cut, hang, tape, finish), but the complete assembly must follow tested details to actually achieve a code‑recognized fire rating.

Where you’d use it

  • Walls and ceilings that must be “fire‑rated” by code (for example, between a house and an attached garage, in multifamily unit separation walls, or in corridors of commercial buildings).
  • Spaces where you want more time for occupants to escape and for firefighters to respond, compared to walls finished with standard drywall.

In simple terms: Type X drywall looks and installs a lot like regular drywall, but because of its specially engineered core, it helps a wall or ceiling resist fire for a longer, tested period, which is why inspectors and codes call for it in specific locations.

Information gathered from public forums or data available on the internet and portrayed here.