Type X is sometimes referred to as fire-rated drywall, and here are three ways that it differs from regular gypsum drywall:

1) Standard drywall is 1/2” thick, but Type X is 5/8” thick.

2) Type X has glass fiber reinforcement in the gypsum core and other additives to help it resist fire longer.

3) Type X must be third-party certified by an independent testing and listing agency such as UL (Underwriters Laboratories Inc.) and ULC (Underwriters Laboratories of Canada) to meet the fire performance requirements prescribed in the ASTM C1396 (CAN/CSA-A82.27) Standard Specification for Gypsum Board. It’s worth noting that, although Type X drywall is often called “one-hour fire rated,” a wall assembly with Type X on both sides and 2x4 stud framing meets the one-hour rating, but the board by itself does not.

    Type X drywall is required for the ceiling of a garage when there is habitable space above, and also at the common wall between units of a duplex or row to townhouses if not masonry.

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Here’s links to a collection of our other blog posts about STRUCTURE AND ROOMS:

• What are the building code requirements for notching and boring holes in a wall stud? 

• What causes dark or light "ghost" lines on ceilings and walls?

• Can you access or exit a bedroom through another bedroom?

• What is the difference between a carport and a garage? 

• What are simple ways to find the cause of a ceiling stain?

• What is the minimum size of habitable rooms in a house according to the building code? 

• Why is my garage ceiling sagging? 

• How can I identify what kind of wood flooring I am looking at?

• Why does my concrete floor slab sweat and get slippery?

• What are the common problems when a homeowner converts a garage to conditioned living space, such as a family room?

• How can I tell if a wall is load-bearing? Which walls can I take out? 

   Visit our STRUCTURE AND ROOMS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.