Flame Spread Rated Fiberglass Batts

Product Description

Lightweight flame-resistant thermal and acoustical fiber glass insulation made of long, resilient glass fibers bonded with an acrylic thermosetting binder. The batts are laminated with an FSK (foil-scrim-Kraft) facing, which enables the insulation to carry a fire hazard classification rating of 25/50 or less per ASTM E 84 and also serves as an excellent vapor retarder. FSK-25 may be left exposed where codes permit.




New Construction

  • Wood frame construction – residential homes and light commercial buildings
  • Metal frame construction – commercial buildings


  • Masonry walls
  • Under roof decks

Performance Advantages

  • Formaldehyde-free – will not off-gas formaldehyde in the indoor environment.
  • Fire-resistant and Noncombustible – (see Specification Compliance). FSK-25 faced insulation can be left exposed where codes permit.
  • Moisture Control – the FSK-25 facing resists water vapor transmission.
  • Light-reflective – when exposed, the FSK-25 reflective surface helps maximize lighting efficiency and may reduce lighting requirements.
  • Thermal Efficiency – provides effective resistance to heat transfer with R-values up to R-30 (RSI-5.3).
  • Sound Control – reduces transmission of sound through exterior walls and floor/ceiling assemblies.
  • Noncorrosive – does not accelerate corrosion of pipes, wiring or metal studs.
  • Durable – unaffected by moisture, oil, grease and most acids. It will not rot, mildew or otherwise deteriorate.
  • Resilient – bonded glass fibers will not pull apart during normal applications and resist settling, breakdown and sagging from vibration.
  • Flexible – forms readily around corners and curved surfaces.