Thermafiber® FireSpan® FF 40 & FF 90


Thermafiber® FireSpan® mineral wool insulation products are designed to maximize fire safety within commercial buildings by providing fire protection in curtain wall and perimeter fire containment systems.

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Thermafiber®  introduces the first formaldehyde free, GreenGuard®  Gold certified perimeter fire containment mineral wool insulation in North America. FireSpan®  is designed to provide enhanced fire protection in curtain wall and perimeter fire containment systems and meet green building standards by using products that exclude red list materials like formaldehyde. These products are non-combustible, moisture-resistant, non-corrosive, non-deteriorating, mildew resistant, and vermin-resistant.1 Its natural dark color provides shadowing in glass spandrels. FireSpan® FF 40 & 90 insulations provide thermal insulation, fire containment, enhanced acoustical performance, and vapor control in many different UL and Intertek (formerly OPL) listed fire containment assemblies of 1, 2, and 3-hr ratings. The new formaldehyde free FireSpan products are especially appropriate for applications in education, healthcare, and other institutions committed to indoor air quality.


Standards, Codes Compliance

ASTM C 665 Type I, III (Class A, Category 1)
ASTM C 612 FireSpan® 40 Type IA, IB, II, III, IVA
ASTM C 612 FireSpan® 90 Type IA, IB, II, III, IVA
ASTM E 136 Non-combustible as defined per NFPA Standard 220
CAN/ULC S114 Complies
ASTM C 1104 Sorption less than 1% by volume
ASTM C 356 Linear Shrinkage <2% @ 1200º F (650º C)
ASTM E 84/CAN/ULC S102 Flame Spread 0, Smoke Developed 0
UL Formaldehyde-Free Validated
GreenGuard Gold certified

Curtain wall products are approved by: New York City Board of Standards & Appeals – (under BSA 214-73-SM & accepted by MEA-209-82, Vol. II). Also, MEA-189-93-M and MEA-190-93-M

Product Options

FireSpan®  40, 2″ or greater thickness, is available with a vapor retarding foil facing.
FireSpan®  90, 1″ or greater thickness, is available with a vapor retarding foil facing.
Recycled Content Options1,2:

  • EPA Choice Fiber
    • (US Government Buildings) ………………………………… Minimum 75%
    • Standard Fiber ……………………………………………………………………… 70%

Technical Data

Tested to ASTM E 84
Tested to ASTM C 518 Unfaced Foil Faced
Nominal Density “k” @ 75° [24°C] .sq. ft. °F
“R” value
per inch of
FireSpan® 40 4.0 pcf 0.23 4.3 0 0 25 0
FireSpan® 90 8.0 pcf 0.23 4.3 0 0 25 0

***R = thickness divided by ‘k’

Perimeter Fire Containment Tests Per ASTM E 2307

FireSpan®  insulation is the insulation for perimeter fire containment. Thermafiber, Inc. has performed decades of testing in all of the containment systems listed below.

  • Aluminum Spandrel Curtain Wall Fire Containment
  • Steel Stud-Framed/Gypsum Sheathing Curtain Wall Fire Containment
  • Glass Spandrel Curtain Wall Fire Containment
  • Granite Spandrel Curtain Wall Fire Containment
  • Precast Concrete Spandrel
  • Steel Back Pan Curtain Wall Fire Containment

For additional job specific details and accessory materials necessary to complete the Perimeter Fire Containment System, please refer to UL®  design listing. Underwriters Laboratories (UL) Designs, Fire Resistance Directory, UL. 333 Pfingsten Road, Northbrook, IL 60062.

See Owens Corning publication “Enclosure Solutions Perimeter Fire Containment System E2307 Curtain Wall Technical Bulletin” (Pub. No. 10020920) for more information.



FireSpan®  products should be mechanically attached to horizontal and vertical mullions with architect approved insulation fasteners. Reinforce FireSpan®  insulation on the outer insulation surface at the safing line. Typical reinforcement members include hat channels, “L” angles, and “T” bars. Thermafiber Inc.’s patented Impasse® system is designed to quickly and easily mechanically attach FireSpan®  insulation to curtain wall systems



Thickness* Widths** Lengths**
FireSpan®  40 2″ – 7″ 24″, 36″, 72″ 48″, 60″, 72″
FireSpan®  90 1″ – 7″ 24″, 36″, 72″ 48″, 60″, 72″
Tolerances +¼” , – ⅛” ± ⅛” +¾”, – ¼”

* Thicknesses are available in 1/2” increments. ** Custom sizes are available upon request.


Thermafiber Insolutions®

Thermafiber Insolutions®  offers industry leading technical and engineering assistance to architects, specifiers, and contractors. These services include CAD drawings, engineering judgments, LEED®  Credit Information, and product recommendations. Contact our technical services department at 02-863-3200 or Email



  • Exceptional performance in Perimeter Fire Containment Systems
  • Provides fire containment in rated assemblies
  • Fire resistant to temperatures above 2,000°F (1,093°C)
  • Helps conserve energy, reduce greenhouse gas emissions
  • Mold-resistant
  • Enhances acoustical performance
  • Natural dark color provides shadowing in glass spandrels
  • Minimum 70% recycled content2
  • Contributes to credits in several green building programs such as LEED® and Green Globes®
  • Formaldehyde Free


Environmental and Sustainability

Owens Corning is a worldwide leader in building material systems, insulation and composite solutions, delivering a broad range of high quality products and services. Owens Corning is committed to driving sustainability by delivering solutions, transforming markets and enhancing lives. More information can be found at