1. Home

Discuss in my forum

Q: What Is Fire Rated Drywall?

A: It's Thicker and A Few Other Things, Too...

By

Rapid Deco® Type X

Sheets of Fire-Rated Rapid Deco® Type X Drywall

Copyright LaFarge
When you are installing drywall, often building code dictates certain types of drywall that must be used. One type of drywall that shows up in building code is fire rated drywall, also known as Type X drywall.

Fire-Rated Is Not Fireproof

Type X is by no means 100% fireproof; simply it is drywall that will stand up against flame longer than regular drywall. If a conventional 1/2" thick sheet of drywall will stand up to 30 minutes of fire, then the added 1/8" found in the Type X drywall, along with its other properties, will increase your margin of safety another 30 minutes. For this reason, fire-rated drywall is sometimes called one hour fire wallboard.

Places to Install Type X Drywall

In residences, fire rated drywall is typically required by building codes to be installed near furnace and utility rooms; places where a wood stove is used; in garages; and on ceilings that up against the main living structure.

Thickness, Composition

Drywall typically comes in 1/4", 3/8", and 1/2" thicknesses. But Type X drywall is 5/8" thick. In addition to the usual gypsum found in regular drywall, fire rated drywall contains glass fibers to form a super-tough core. Not only that, the gypsum and fiberglass are packed in tighter and denser than in regular drywall.

Cost and Availability

Fire rated drywall costs more than the regular drywall. As a rule of thumb, you can count on it costing about 5% to 7% more than conventional drywall of the same thickness. Type X is not a specialty product; it is available at local home improvement stores or contractors' supply houses.

Two added benefits to Type X drywall: it inhibits sound transmission and it stands up well to impact.

If you want fire rated drywall to be installed all throughout your house, you would need to request this with the contractor, as this is not normally done.

Summary

  • 5/8"
  • Glass fibers added.
  • Denser than normal gypsum-only drywall.
  • Up to 1 hour fire rating.
  • Also called Type X drywall.
  • Absorbs sound well.

©2014 About.com. All rights reserved.