Our Products

STI CS Composite Sheet

Availability: In stock

SpecSeal Composite Sheet is the ideal solution for large openings where a permanent seal is required. Composite sheet consists of a thin sheet steel with intumescent embedded onto a single side. Composite sheet partners with other SpecSeal firestop products such as Firestop Collars and EZ Path Devices to size down oversized openings.

Share this to:

Product Description


  • Profession Fit and Finish
  • Partners with other SpecSeal Firestop Products
  • Easily cut with hand sheers
  • Tested for up to 4 Hours of fire resistance when tested to ASTM E814/UL147
Application Properties
Blank Opening  Finished Product
Busway Intumescent
Cables Light Weight
Cable Tray Low VOC
Duct No Expiration
Metal Pipe Paintable
Multiple Penetrations Re-Enterable
  Smoke Barrier
  STC Rating



Property Value
Nominal Thickness 0.1 in (2.5 mm)
Mominal Weight 1.4 lb/sqft (6.9 kg/sqm) Intumescent
Expansion Begins 350ºF (177ºC)
Volume Expansion 15x (typical free expansion)
In Service Temperature -10ºF (-23ºC) to 130ºF (54ºC)
Storage Temperature Less than 130ºF (54ºC)
Radiation Exposure Unaffected
STC Rating 55 (Relates to specific construction) (ASTM E 90-04)
VOC Content N/A
Shelf Life No Limit


Ordering Information

Catalogue Number Description (UOM) Qty. Case Qty. Weight (Each)
STI_CS1628 16" x 28" (41 cm x 71 cm) 1 1 5.80 lbs (2.63 kg)
STI_CS2436 24" x 36" (61 cm x 92 cm) 1 1 10.65 lbs (4.83 kg)
STI_CS3636 36" x 36" (92 cm x 92 cm) 1 1 15.65 lbs (7.10 kg)
STI_CS3641 36" x 41" (92 cm x 104 cm) 1 1 16.60 lbs (7.53 kg)
STI_CS2852 28" x 52" (71 cm x 132 cm) 1 1 12.95 lbs (5.87 kg)