STI Firestop Equivalents & Alternatives
Switching from STI (Specified Technologies) firestop? Every STI firestop product has a UL-tested Metacaulk® (RectorSeal) equivalent — same performance class, distributor pricing, same-day shipping from New Jersey. 19 product categories cross-referenced below, with free submittal support when your job specs STI.
| STI Product | Metacaulk® Equivalent | Why contractors switch |
|---|---|---|
SpecSeal Series – SSS Intumescent Caulk | Metacaulk 1000General-purpose intumescent, UL up to 4hr, STC 62 | MC 1000 offers the best balance of price and performance for general intumescent needs. |
LC, LCI, WF300 SpecSeal ES Multi-Purpose Caulk | Metacaulk 150+All-purpose, STC 65, Buy America compliant | MC 150+ covers the most UL systems of any single sealant. Best value for general contractors. |
LC & SpecSeal ES Elastomeric | MC 1200Ultra-flexible, CG/SL/Spray, red/white/gray | MC 1200 uniquely offers caulk grade, self-leveling, AND spray formulations. |
SIL 300 Silicone Caulk | Metacaulk 835+Silicone-based, Class 25 movement, ASTM C920 | 835+ offers true silicone performance with Class 25 movement capability. |
SIL300 SL Silicone Self-Leveling | Metacaulk 835+ SLSelf-leveling silicone for floor penetrations | Self-leveling silicone for horizontal joints. Apply and walk away. |
SmokeBlock 200 Foam Firestop | RS136 SmokeBlockEconomical foam firestop | RS136 is the budget-friendly option for basic through-penetrations. |
SmokeBlock 200 Foam / Draft / FireBlock | Draft Block OrangeOrange foam for draft stopping | Draft Block Orange targets residential/light commercial draft stopping. |
Fast Tack Silicone Spray | Metacaulk 835+ SprayFast-cure spray silicone | 835+ Spray offers fast-cure spray application for large area coverage. |
AS200 Elastomeric Spray Spray Mastic | Metacaulk 1200 SprayElastomeric spray mastic | MC 1200 Spray covers large areas fast. Available in red and white. |
SSP Putty Putty Sticks | MC FRS Putty StickMoldable intumescent putty | FRS Putty Sticks are moldable — perfect for irregular openings. |
SSP Putty Pads Putty Pads | MC FRP Putty PadsSelf-adhesive pads for electrical boxes | Fastest way to firestop electrical boxes. Available in 6x7, 7x7, 9x9. |
SpecSeal Collar Pipe Collars | Intumescent CollarsSteel collars, 1.5-6 inches | Available in 5 sizes for PVC, CPVC, ABS, PP, PE pipes. |
EZ Path Cast-In Devices | CIDFactory-assembled, cast into concrete | CIDs save significant field labor — cast them in and the firestop is done. |
SpecSeal Pillow Firestop Pillows | Firestop PillowsRe-enterable, 2 and 3 inch | Re-enterable — pull out, add cables, put back. No re-caulking. |
SpecSeal Strip Joint Strip | Joint StripIntumescent strip, 1-4 inch widths, 82ft rolls | 82-foot rolls for head-of-wall and perimeter joints. |
SpecSeal Wrap Wrap Strip | Wrap StripIntumescent wrap for plastic pipes | Wrap around plastic pipes before sealing. Expands in fire to seal. |
SpecSeal Board Composite Sheet | Composite Sheet36x36 inch firestop board, up to 3hr | Cut with standard tools. Use with sealants for large openings. |
SpecSeal Mortar Fire-Rated Mortar | FRM Mortar45lb bag, just add water, up to 3hr | Go-to for large floor openings. 1 bag = 1 cubic foot. |
Cable Coating Cable Coating | C70 Cable CoatingIndustrial spray/brush, gray and white | Designed for industrial cable tray protection. Spray or brush. |
Note: Cross-reference is general guidance — always verify the specific UL system for your assembly. Job specs STI? We provide UL system documentation and submittal support free — call (732) 757-4552 or email sales@firestop-usa.com.
STI equivalents — frequently asked
What is the Metacaulk equivalent to STI SpecSeal Series – SSS?
Metacaulk 1000 — General-purpose intumescent, UL up to 4hr, STC 62. MC 1000 offers the best balance of price and performance for general intumescent needs.
What is the Metacaulk equivalent to STI LC, LCI, WF300 / SpecSeal ES?
Metacaulk 150+ — All-purpose, STC 65, Buy America compliant. MC 150+ covers the most UL systems of any single sealant. Best value for general contractors.
What is the Metacaulk equivalent to STI LC & SpecSeal ES?
MC 1200 — Ultra-flexible, CG/SL/Spray, red/white/gray. MC 1200 uniquely offers caulk grade, self-leveling, AND spray formulations.
What is the Metacaulk equivalent to STI SIL 300?
Metacaulk 835+ — Silicone-based, Class 25 movement, ASTM C920. 835+ offers true silicone performance with Class 25 movement capability.
What is the Metacaulk equivalent to STI SIL300 SL?
Metacaulk 835+ SL — Self-leveling silicone for floor penetrations. Self-leveling silicone for horizontal joints. Apply and walk away.
What is the Metacaulk equivalent to STI SmokeBlock 200?
RS136 SmokeBlock — Economical foam firestop. RS136 is the budget-friendly option for basic through-penetrations.
What is the Metacaulk equivalent to STI SmokeBlock 200?
Draft Block Orange — Orange foam for draft stopping. Draft Block Orange targets residential/light commercial draft stopping.
What is the Metacaulk equivalent to STI Fast Tack?
Metacaulk 835+ Spray — Fast-cure spray silicone. 835+ Spray offers fast-cure spray application for large area coverage.
What is the Metacaulk equivalent to STI AS200 Elastomeric Spray?
Metacaulk 1200 Spray — Elastomeric spray mastic. MC 1200 Spray covers large areas fast. Available in red and white.
What is the Metacaulk equivalent to STI SSP Putty?
MC FRS Putty Stick — Moldable intumescent putty. FRS Putty Sticks are moldable — perfect for irregular openings.
What is the Metacaulk equivalent to STI SSP Putty Pads?
MC FRP Putty Pads — Self-adhesive pads for electrical boxes. Fastest way to firestop electrical boxes. Available in 6x7, 7x7, 9x9.
What is the Metacaulk equivalent to STI SpecSeal Collar?
Intumescent Collars — Steel collars, 1.5-6 inches. Available in 5 sizes for PVC, CPVC, ABS, PP, PE pipes.
Is Metacaulk a good alternative to STI firestop?
Yes. Metacaulk (manufactured by RectorSeal) offers UL Classified equivalents for STI (Specified Technologies) firestop products across sealants, sprays, collars, wraps, putty, devices and mortar — typically at meaningfully lower cost. Always verify the specific UL system for your assembly; our team can help match systems.
Can I substitute Metacaulk on a job that specs STI?
In most cases, yes — when the substitution is approved through a submittal showing an equivalent UL Classified system. Firestop-USA provides product data, UL system documentation and submittal support at no charge. Call (732) 757-4552 and we'll match the system.
Do you offer distributor pricing and fast shipping?
Yes — Firestop-USA is an authorized Metacaulk master distributor: distributor pricing, volume discounts, same-day shipping on in-stock items ordered before 11 AM, and free freight over $2,500, shipping nationwide from New Jersey.
Ready to switch from STI?
Distributor pricing, same-day shipping before 11 AM, free freight over $2,500, and free submittal support — from an authorized Metacaulk master distributor.
Also switching from Hilti firestop or 3M firestop? See the complete cross-reference chart.