Register Login Logout Account
Choose Region: North America

The Incredible Shrinking… Firestop Sealant?

Do firestop sealants shrink? This is a question that has been bandied about at various industry meetings. The simple answer is yes. Sealants may exhibit various degrees of shrinkage dependent upon the environment in which they are installed. The majority of the firestop sealants on the market are latex based or silicone based, so we will constrain our discussion to those two types of sealant technology. For the most part, silicone sealants exhibit a negligible amount of shrinkage (generally <5%). Latex sealants, on the other hand, may shrink much more. Historically speaking, latex sealants have been on the market for more than 30 years, and while nothing has changed significantly, it is more of an issue today because of increased inspection, and specifically, destructive sampling where the dried sealant is cut and measured.

Latex based sealants dry rather than cure. The curing mechanism is quite simple and is somewhat analogous to a mud puddle drying. In a more humid environment, the sealant will draw moisture in and this can prolong the drying. Conversely, in an arid environment, the sealant will dry very quickly and the sealant may actually achieve its ultimate profile faster. Adding to the complexity of the appearance of the sealant, the geometry of the opening may induce more apparent shrinkage such as sealant applied across a larger span. In some cases, this is actually designed into the sealant. How can this be? The most optimal sealant profile to accommodate movement is an hourglass profile. In the past, installers might use a tooling knife to induce this concavity. However, some sealants will actually dry to be thicker towards the adhesion points (e.g. penetrant interface and barrier interface) and thinner towards the center.

So if a concave profile is ideal, why does it become an issue with some inspectors? The trouble with destructive testing is that often times a dry sealant application is being dissected and compared to a UL Certified System that reports a wet depth! When UL Systems are developed, the test lab measures the wet depth of the applied sealant and the resultant listings report the wet depth. It does not consider the shrinkage and the dried sealant profile. However, UL does reference the percentage of anticipated shrinkage according to ASTM C1241 and reports it (optionally) for the various latex based sealants. They also make a note in both the XHEZ and XHBN Guide Information that sealants may be prone to some degree of shrinkage and the systems report a wet depth unless otherwise indicated. According to ASTM C1241 testing, some sealants may shrink 20 to 25%. What does this mean? Well, if the installed depth was 1”, then it is possible to measure a dry sealant membrane that is almost a ¼” thinner. The listings cannot list a wet and dry depth because variations in annular space, opening shape, and penetrant size may produce a variety of different dry sealant profiles. One of the problems is variations in how inspectors perform cut tests on applied sealants. There is not always consistency. The IFC published a recommendation on how to perform cut tests. The IFC recommends measuring sealants at the adhesion points rather than towards the middle of the sealant to provide a better indicator of the original applied sealant thickness.

What can you do if you are flagged during an inspection and suspect that the sealant has shrunk? First, point the inspector to the UL Guide Information statements on sealant shrinkage. Next, provide the sealant listing card with the ASTM C1241 test results. Finally, verify if the inspector is following the IFC Recommendations when performing destructive testing. Please do not hesitate to contact STI Technical Services to enlist our help.

 Literature

userguide1

User Guide: North America

The perfect brochure to use as a reference tool for any STI Product on the market.

+ View Brochure PDF

userguide international

User Guide: International

Our complete product brochure designed for international markets.

+ View Brochure PDF

EZ-Path® Fire Rated Pathway

Our complete EZ-Path® product line in one convenient location.

+ View Brochure PDF

EZ-Path® Retrofit Device

Our complete brochure for the EZ-Path® Retrofit Device.

+ View Brochure PDF

EZ-Path® The Logical Choice

EZ-Path® saves time, money, and resources by removing ongoing downstream costs.

+ View Brochure PDF

Perimeter Fire Barrier Systems

STI is dedicated to providing our clients and partners with the industry’s most advanced cost-effective solutions for perimeter fire barrier systems.

+ View Brochure PDF

Wood Frame Brochure

STI’s Wood Frame fire & smoke products

+ View Brochure PDF

Available Literature:

+ User Guide: US & Canada
+ User Guide: Europe & Middle East
+ Electrical & DataCom User Guide
+ EZ-Path® Fire Rated Pathway

Your Name (required)

Email (required)

Phone Number (required)

Company (required)

Street (required)

City (required)

State (required)

Zipcode (required)

Country (required)

Literature Request (Name and Quantity)

Additional Message

 Warranty Information

Limited Warranty

STI warrants that its products will be free of defects for one year from the date of purchase. In the event a product does not conform to this warranty, the sole and exclusive remedy is, at STI’s option, replacement of the product or refund of the purchase price. The warranty provided herein shall be void and of no effect in the event that the product is not installed in accordance with STI’s published instructions, listed systems and applicable building and safety codes. THIS WARRANTY IS IN LIEU OF ALL OTHER REPRESENTATIONS AND EXPRESSED OR IMPLIED WARRANTIES (including the implied warranties of merchantability or fitness for a particular use) AND UNDER NO CIRCUMSTANCES SHALL STI BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING, WITHOUT LIMITATION, ANY LOSS OF REVENUE, PROFIT OR USE. Prior to use, the user shall determine the suitability of the product for its intended use, and the user assumes all risks and liability for subsequent use. No person other than an officer of STI is authorized to bind STI to any other warranty for any product for which this warranty is issued.

 CAD Detail Sheets

Detail sheets are documents grouped together with the most commonly used systems in five categories. These files can be downloaded as either a PDF or DWG file.

Click here to generate a custom Detail Sheet.

caddetails1

Construction Joints
View PDF | View DWG

Curtain Wall
View PDF | View DWG

Electrical-DataCom
View PDF | View DWG

EZ-Path®
View PDF | View DWG

Plumbing – HVAC
View PDF | View DWG

 STI Guide Specifications

 Data Sheets

Penetrations

  1. Caulks, Sealants & Putties
    Product
    Product Data Sheet
    Safety Data Sheet
    SSS Intumescent Sealant
    pdf_icon_small
    pdf_icon_small
    LCI Intumescent Sealant
    pdf_icon_small
    pdf_icon_small
    SIL Silicone Sealant (Non-Sag)
    pdf_icon_small
    pdf_icon_small
    SIL Silicone Sealant (Self-Leveling)
    pdf_icon_small
    pdf_icon_small
    PEN200 Silicone Foam
    pdf_icon_small
    pdf_icon_small
    WF Caulk
    pdf_icon_small
    pdf_icon_small
    LC Endothermic Sealant
    pdf_icon_small
    pdf_icon_small
    SSP Putty
    pdf_icon_small
    pdf_icon_small
    SSP Putty Pads
    pdf_icon_small
    pdf_icon_small


  1. Collars, Wrap Strip & Cast-In
    Product
    Product Data Sheet
    Safety Data Sheet
    CID Cast-In Firestop Device
    pdf_icon_small
    pdf_icon_small
    SSC Intumescent Firestop Collars
    pdf_icon_small
    pdf_icon_small
    LCC Intumescent Firestop Collars
    pdf_icon_small
    pdf_icon_small
    RTC Intumescent Firestop Collars
    pdf_icon_small
    pdf_icon_small
    BLU Wrap Strip
    pdf_icon_small
    pdf_icon_small
    BLU2 Wrap Strip
    pdf_icon_small
    pdf_icon_small
    BLU220, BLU230, BLU240 Wrap Strip
    pdf_icon_small
    pdf_icon_small
    RED Wrap Strip
    pdf_icon_small
    pdf_icon_small
    RED2 Wrap Strip
    pdf_icon_small
    pdf_icon_small
    SSW125, SSW250, SSW375 Wrap Strip
    pdf_icon_small
    pdf_icon_small


  1. EZ-Path Fire-Rated Pathways
    Product
    Product Data Sheet
    Safety Data Sheet
    EZ-Path 44+
    pdf_icon_small
    pdf_icon_small
    EZ-Path 33
    pdf_icon_small
    pdf_icon_small
    EZ-Path 22
    pdf_icon_small
    pdf_icon_small
    EZ-Path Retrofit Device
    pdf_icon_small
    pdf_icon_small
    EZ Firestop Grommet
    pdf_icon_small
    pdf_icon_small


  1. Electrical & DataCom Cabling
    Product
    Product Data Sheet
    Safety Data Sheet
    EZ-Path 44+
    pdf_icon_small
    pdf_icon_small
    EZ-Path 33
    pdf_icon_small
    pdf_icon_small
    EZ-Path 22
    pdf_icon_small
    pdf_icon_small
    EZ-Path Retrofit Device
    pdf_icon_small
    pdf_icon_small
    EZ Firestop Grommet
    pdf_icon_small
    pdf_icon_small
    SSS Intumescent Firestop Sealant
    pdf_icon_small
    pdf_icon_small
    LCI Intumescent Firestop Sealant
    pdf_icon_small
    pdf_icon_small
    SSB Intumescent Firestop Pillows
    pdf_icon_small
    pdf_icon_small
    Composite Sheet
    pdf_icon_small
    pdf_icon_small
    SSM Firestop Mortar
    pdf_icon_small
    pdf_icon_small
    Electrical Box Insert
    pdf_icon_small
    pdf_icon_small
    SSP Putty
    pdf_icon_small
    pdf_icon_small
    SSP Putty Pads
    pdf_icon_small
    pdf_icon_small
    FP Intumescent Firestop Plug
    pdf_icon_small
    pdf_icon_small
    Ready® Sleeve
    pdf_icon_small
    pdf_icon_small
    Ready® Split Sleeve
    pdf_icon_small
    pdf_icon_small
    EZ-Path® Series 33NEZ Smoke and Acoustical Device (Wall – Blue)
    pdf_icon_small
    pdf_icon_small
    EZ-Path® Series 33NEZ Smoke and Acoustical Device (Wall – White)
    pdf_icon_small
    EZ-Path® Series 33NEZ Smoke and Acoustical Device (Ceiling)
    pdf_icon_small
    pdf_icon_small
    EZ-Path® Series 44NEZ Smoke and Acoustical Device
    pdf_icon_small
    pdf_icon_small


  1. Electrical Circuit Protection
    Product
    Product Data Sheet
    Safety Data Sheet
    Cable Spray
    pdf_icon_small
    pdf_icon_small
    Thermal Barrier Wrap
    pdf_icon_small
    pdf_icon_small


  1. Outlet & Panel Box Protection
    Product
    Product Data Sheet
    Safety Data Sheet
    Electrical Box Insert
    pdf_icon_small
    pdf_icon_small
    SSP Putty
    pdf_icon_small
    pdf_icon_small
    SSP Putty Pads
    pdf_icon_small
    pdf_icon_small
    Thermal Barrier Wrap
    pdf_icon_small
    pdf_icon_small


  1. Large Opening
    Product
    Product Data Sheet
    Safety Data Sheet
    SSB Intumescent Firestop Pillows
    pdf_icon_small
    pdf_icon_small
    Composite Sheet
    pdf_icon_small
    pdf_icon_small
    SSM Firestop Mortar
    pdf_icon_small
    pdf_icon_small


  1. Packing/Forming Materials
    Product
    Product Data Sheet
    Safety Data Sheet
    STI-SSAMW
    pdf_icon_small
    pdf_icon_small
    IIG (JM)-Type CW8
    pdf_icon_small
    pdf_icon_small
    IIG (JM)-Minwool 1200 Safing
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Firespan 40 & 90
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Impasse System Complete
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Impasse System Hangers
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Impasse System Spiral Anchors
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Safing
    pdf_icon_small
    pdf_icon_small
    Roxul-CurtainRock 40
    pdf_icon_small
    pdf_icon_small
    Roxul-CurtainRock 80
    pdf_icon_small
    pdf_icon_small
    Roxul-Safe
    pdf_icon_small
    pdf_icon_small


  1. Other
    Product
    Product Data Sheet
    Safety Data Sheet
    FyreFlange HVAC Firestop Angle
    pdf_icon_small
    pdf_icon_small
    Closet Flange Firestop Gasket
    pdf_icon_small
    pdf_icon_small

Construction Joints

  1. Joint Sprays
    Product
    Product Data Sheet
    Safety Data Sheet
    AS200 Elastomeric Spray
    pdf_icon_small
    pdf_icon_small
    Fast Tack® Firestop Spray
    pdf_icon_small
    pdf_icon_small


  1. Joint Sealants
    Product
    Product Data Sheet
    Safety Data Sheet
    SSS Intumescent Firestop Sealant
    pdf_icon_small
    pdf_icon_small
    LCI Intumescent Firestop Sealant
    pdf_icon_small
    pdf_icon_small
    SIL Silicone Sealant (Non-Sag)
    pdf_icon_small
    pdf_icon_small
    SIL Silicone Sealant (Self-Leveling)
    pdf_icon_small
    pdf_icon_small
    ES Elastomeric Firestop Sealant
    pdf_icon_small
    pdf_icon_small
    LC Endothermic Firestop Sealant
    pdf_icon_small
    pdf_icon_small


  1. SpeedFlex Joint Protection
    Product
    Product Data Sheet
    Safety Data Sheet
    SpeedFlex® TTG Track Top Gasket
    pdf_icon_small
    pdf_icon_small
    SpeedFlex® Joint Profile System
    pdf_icon_small
    pdf_icon_small

Curtain Wall

  1. Perimeter Fire Barrier Sprays
    Product
    Product Data Sheet
    Safety Data Sheet
    AS200 Elastomeric Spray
    pdf_icon_small
    pdf_icon_small
    Fast Tack® Firestop Spray
    pdf_icon_small
    pdf_icon_small
    Safing Spray
    pdf_icon_small
    pdf_icon_small


  1. All Weather Firestop Sprays
    Product
    Product Data Sheet
    Safety Data Sheet
    Fast Tack® Firestop Spray
    pdf_icon_small
    pdf_icon_small


  1. Anchor Protection
    Product
    Product Data Sheet
    Safety Data Sheet
    Connection Protection
    pdf_icon_small
    pdf_icon_small


  1. Curtain Wall Insulation Materials
    Product
    Product Data Sheet
    Safety Data Sheet
    STI-SSAMW
    pdf_icon_small
    pdf_icon_small
    IIG (JM)-Type CW8
    pdf_icon_small
    pdf_icon_small
    IIG (JM)-Minwool 1200 Safing
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Firespan 40 & 90
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Impasse System Complete
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Impasse System Hangers
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Impasse System Spiral Anchors
    pdf_icon_small
    pdf_icon_small
    Owens Corning Thermafiber-Safing
    pdf_icon_small
    pdf_icon_small
    Roxul-CurtainRock 40
    pdf_icon_small
    pdf_icon_small
    Roxul-CurtainRock 80
    pdf_icon_small
    pdf_icon_small
    Roxul-Safe
    pdf_icon_small
    pdf_icon_small

Smoke & Acoustical

  1. EZ-Path Smoke & Acoustical Pathway
    Product
    Product Data Sheet
    Safety Data Sheet
    EZ-Path® Series 33NEZ Smoke and Acoustical Device
    pdf_icon_small
    pdf_icon_small
    EZ-Path® Series 33NEZ Smoke and Acoustical Device (Ceiling)
    pdf_icon_small
    pdf_icon_small
    EZ-Path® Series 44NEZ Smoke and Acoustical Device
    pdf_icon_small
    pdf_icon_small


  1. Sealants & Sprays
    Product
    Product Data Sheet
    Safety Data Sheet
    Application Data Sheet
    Smoke N Sound Acoustical Spray
    pdf_icon_small
    pdf_icon_small
    pdf_icon_small
    Smoke N Sound Acoustical Sealant
    pdf_icon_small
    pdf_icon_small
    pdf_icon_small

Fireblocking/Draftstopping

  1. SmokeBlock
    Product
    Product Data Sheet
    Safety Data Sheet
    SmokeBlock® 136
    pdf_icon_small
    pdf_icon_small
    SmokeBlock® 200
    pdf_icon_small
    pdf_icon_small

 Approval Information

 New & Improved Systems

 Specification Review Services

Did you know that many specifications for firestopping reference older fire test standards or obsolete products?

Let our firestop experts assist by reviewing your firestop specifications and making appropriate recommendations. STI provides this service free of charge.

 Technology Updates

 The Burn Newsletter