Firestall® Roof Deck

Firestall® Roof Decking is a nailable Class "A" fire rated structural roof decking, made of multiple plies of Homasote structural board and a face ply of UL-listed N.C.F.R.® Homasote.®

It is designed for use as a structural, load-bearing decking in residential and commercial buildings that require a Class A (25 flame spread) rated decking.



  • Can be applied over either steel or wood framing or structural steel deck
  • Provides a nailbase surface to attach additional insulation, shingles and other finish roofing

Sizes & Weights (nominal), Thermal Resistance

Thickness Size Weight R Value
1.0" 2' x 8' 2.62 lbs./sq.ft. 2.05
1-3/8" 2' x 8' 3.48 lbs./sq.ft. 2.5
1-7/8" 2' x 8' 4.63 lbs./sq.ft. 3.1

NOTE: Finished T&G on long edges and square on ends.

Fire Resistance Ratings

Method of Test Class Flame Spread Smoke Developed
ASTM-E84 A 20 5

Load Table*

Panel Thickness Maximum Rafter Spacing for
live loads of 50 PSF*
1" 24"
1-3/8" 32"
1-7/8" 48"-40" PSF

* Calculations based on 2 or more continuous spans. 10 PSF dead load assumed.

Typical Physical Properties

  440 Surface NCFR Surface
Density: 26-28 lbs./ft. 34-40 lbs./ft.
Tensile Strength: 450-700 psi 400-700 psi
Hardness, Janka Ball (min.): 230 275
Water Absorption by vol. (max.):
  2 hrs. immersion
Expansion from 50%-90%
Relative humidity (maximum)
0.25% 0.30%
Flame Spread (NCFR surface) Class I (or A)  
Noise Reduction Coefficient .20  

Code Compliance

1992 BOCA National Building Code Section 2310.2, Fire retardant-Treated Wood.