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Mfr:STI Firestop

SpecSeal Silicone Joint Sealant 10 Ounce Cartridge

Item #: SSPEN300.SC*NA

Mfr. Part #: SIL300


SpecSeal SIL300 Silicone Sealant is a high performance silicone firestop sealant tested to resist the passage of smoke, flame and water through construction joints and through-penetrations. SIL300 Sealant cures to form a flexible seal and carries a Class 1 W Rating for water...

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Available: 2

Case Quantity: 24



San Diego






Salt Lake




San Marcos


(*) Minimum Quantity: 1

About This Product


SpecSeal SIL300 Silicone Sealant is a high performance silicone firestop sealant tested to resist the passage of smoke, flame and water through construction joints and through-penetrations. SIL300 Sealant cures to form a flexible seal and carries a Class 1 W Rating for water resistance (Per ANSI/UL1479).

  • Low modulus allows dynamic movement in joints
  • Non-halogenated
  • Auto bonding allows fresh sealant to adhere to cured sealant
  • Excellent water resistance for water-tight sealing; including class 1 W ratings (UL1479)
  • Ozone and UV resistant for excellent weathering ability and long service life
  • Excellent chemical resistance protects in polluted or corrosive atmospheres
  • Excellent adhesion to most building substrates
  • Excellent smoke seal
  • Neutral cure
  • Safe, no asbestos, no PCB’s, no inorganic fibers
  • Meets LEEDTM v3, v4, & v4.1 requirements. Low emitting materials credit. See general LEED letter for additional applicable credits


  • Blank Opening
  • Bottom of Wall
  • Busway
  • Cable Tray
  • Floor to Floor
  • Floor to Wall
  • Head of Wall
  • Metal Pipe
  • Multi. Pen.
  • Wall to Wall

SpecSeal SIL Silicone Firestop Sealant is used to seal both through-penetration firestop systems and joint systems. Representative systems have been tested involving primarily noncombustible penetrants, electrical, data, or telephone cables, construction gaps, expansion joints, curtain wall safing applications, and top-of-wall joints.


The silicone firestop sealant shall be a one-part, neutral-cure meeting the requirements of ASTM C920. The firestop sealant shall be UL Certified and tested to ASTM E814 (UL1479), ASTM E1966 (UL2079), and CAN/ULC-S115. Class 1 W Ratings per UL1479 shall be available for a variety of different firestop systems.

Test Standards

  • ASTM C920
  • ASTM E814 (UL1479)
  • ASTM E1966 (UL2079)
  • CAN/ULC-S115
  • ASTM E119 (UL 263)

Specified Divisions

  • Division 7 07 84 13 Penetration Firestopping
  • Division 7 07 84 43 Joint Firestopping
  • Division 22 22 00 00 Plumbing
  • Division 23 23 00 00 HVAC
  • Division 26 26 00 00 Electrical

Product Video


SIL Silicone Firestop Sealant Documents


SIL Silicone Firestop Sealant Specifications

Shipping & Returns

Sunshine Supply prides itself on providing only the best waterproofing products to the construction industry. Unfortunately, products we offer may not always meet our customers expectations. If this is the case, we are happy to accept your return and help you find a product that better fits your needs. (see return policy below)

If the reason for your return is a result of a mistake made by Sunshine Supply, we will provide a full product refund along with all tax, shipping, and handling fees applicable to your sale. Return shipping, if necessary, will be processed and scheduled by Sunshine Supply. Please, do not send back your products without consulting a customer service representative first to ensure a quick and easy refund.

Please inform Sunshine Supply immediately if any of your items are missing or damaged upon arrival. Make sure to notate all damages on the shipping receiver from our carriers or Sunshine Supply’s packing slip.

In the event we are unable to accept return of a product due to damage or leaking material. Sunshine Supply will provide a full refund, assuming it meets eligibility of our return policy, but expect the customer to dispose of the materials following all Southern California disposal guidelines.

Returns are fast and easy, but we do have a couple exceptions for products to be eligible for return. The exceptions are as follows:

  • The original purchase date must be 30 days or less. Returns may be subject, but not limited to, a 20% restock fee if the return is made after 30 days. Returns older than 60 days will not be accepted.
  • The product is in original, unopened manufactures packaging.
  • The product is not expired or close to its expiration date.
  • If applicable, product lot/batch number is clearly visible and matching the original sale lot/batch number.
  • Not all returns are the same and it is difficult to outline every instance that meets return eligibility. If your return does not meet the requirements above please give us a call and we will attempt to remedy the situation in some other way. The satisfaction of our customers is Sunshine Supply’s top concern.

Here is some legal jargon from our Terms and Conditions:


Sunshine Supply Co., Inc. is under no obligation to accept return of products purchased by customer whether or not they are special order. Sunshine Supply Co., Inc. may, in its sole discretion, accept a return of products and provide a credit to the customer’s account if (I) the products were purchased from Sunshine Supply Co., Inc., (II) the product is not visibly defective or impaired or have expired expiration dates, (III) the product is returned within thirty (30) days of the date of sale, and (IV) the product is in the original manufacturer’s packaging with Lot/Batch number clearly legible and matching the original sale. If Sunshine Supply Co., Inc. accepts the return of product, a restocking fee of 20% of the purchase price shall be deducted from all credited amounts from all stock, non-stock, or special order product. Additional limitations or costs may be imposed upon their return including those required by the manufacturer of the product.

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