One-part silicone rubber.

DOWSIL™ FIRESTOP 700 Sealant is a low modulus, one-part, neutral curing, fire-rated silicone sealant. It has excellent unprimed adhesion to a range of common construction substrates including stone, steel, masonry, brick, wood, etc. It is ideal for weather-sealing of curtain walling, building facades and expansion joints where a fire rating is required. It is also suitable for use in penetration sealing systems where pipes and cables pass through fire rated structures.

  • Meets BS 476 Part 22
  • Excellent unprimed adhesion to most porous and non-porous construction substrates
  • Non-slump
  • Joint movement capability ±50%
  • Neutral cure
  • Halogen-free
  • Conforms to ISO 11600-F&G-25LM
  • A fire rating of up to 4 hours can be achieved
  • Widely tested to many European specifications
  • Tack-free in 1.5 hours
  • Excellent weathering characteristics, including resistance to ozone, UV radiation and temperature extremes
  • Long service life
  • CE marked as a fire resistant according to ETAG 026
  • The sealing of expansion joints and pipe and cable penetrations in fire rated structures.
  • The provision of fire rated systems where expansion joints or penetration seals are required in curtain walling, building facades or partition walls.
Typical Properties

Specification writers: These values are not intended for use in preparing specifications. Please contact your local Dow Corning sales representative prior to writing specifications on this product.

Property Unit Result
As Supplied
Slump mm Max. 1
Working Time minutes 15
Application Temperature °C C
+5 to +40
°F +41 to +104
Tack-free time (23°C, 50% R.H.) hours 1.5
Cure rate (23°C, 50% R.H.) 1 day mm after 1 day: 2
Joint movement capability % ±50


Technical Specifications & Standards

DOWSIL FIRESTOP 700 Sealant has been tested to BS 476 Part 22/1987 in expansion joint configurations, Fulmer Yarsley Test Report No. J82973/1 and SGS Test Report No. J86464/1.

It also has been tested to BS.476 Part22/1987 (ISO 834) in pipe and cable penetration systems, Fulmer Yarsley Test Report No. J82973/2.

It meets ISO 11600-F&G-25LM.

In compliance with the fire resistance requirement according to ETAG 026

• Euroclass B according to EN 13501-1 (Reaction to fire)
• 2 to 4 hours fire resistance according to EN 1366-4 (Resistance to fire)

It meets the requirements of SNJF category 1 sealants.

It meets the requirements of DIN 18545, T2 and Class E of DIN 18540, T2, ISO 11600-F&G-25LM.

Fire Ratings

Fire test data is available illustrating that DOWSIL FIRESTOP 700 Sealant can achieve up to a 4 hour fire rating at specified joint and penetration configurations.

The test data provides a good indication of the expected performance of the sealant in fire situations. Users should satisfy themselves that specific applications for which DOWSIL FIRESTOP 700 Sealant is proposed are suitable and testing of a particular system may be required.

To achieve any specific fire rating, all substrates being used in the system must have at least an equivalent fire rating.

Substrate Preparation

Ensure that all surfaces are clean, dry, sound and free from frost. Clean all joints of release agents, water repellents, laitance, dust, dirt, old sealants and other contaminants which could impair adhesion. Metal surfaces should be cleaned and degreased by wiping with a suitable solvent using an oil- and lint-free cloth. For further advice on cleaning specific substrates please contact technical services department.

Note: When using any solvent, always provide adequate ventilation. Avoid heat, sparks and open flames. Observe and follow all precautions listed on solvent container label or Product Safety Data Sheet.

DOWSIL FIRESTOP 700 Sealant should not be applied to surfaces that are below 5°C (41°F) as it is impossible to guarantee a dry, frost-free surface at these temperatures.

DOWSIL FIRESTOP 700 Sealant has excellent adhesion to most common construction substrates. If in doubt, or if unusual substrates are involved, please contact the technical services department. Cement or concrete should be primed with DOWSIL™ P Primer for optimum adhesion.
Dow will carry out specific adhesion and compatibility testing on individual substrates to ensure that correct recommendations can be made. If there is any doubt concerning any aspect of the use of DOWSIL FIRESTOP 700 Sealant, users are strongly advised to contact technical services department.

Back-up materials
Backer materials have been evaluated in various joint designs, these being closed-cell polcorningyethylene foam backer rod, ceramic fiber and mineral wool. In penetration sealing applications, mineral wool has been evaluated. Depending on the fire rating required and the joint/penetration design, the most suitable system can be selected by referring to the rating tables (see Table 1).

Areas adjacent to the joints should be masked with tape to prevent contamination of the substrates and to ensure a neat sealant line. Masking tape should be removed immediately after tooling.

The joint should be tooled within 5 minutes of application to ensure good contact between the sealant and the substrate. Tooling of the sealant also gives a smooth, professional finish.

Excess sealant should be cleaned off tools and non-porous surfaces whilst in an uncured state using a suitable solvent, such as DOWSIL™ R-40 Universal Cleaner. Sealant adhering to porous surfaces should be left until just cured and then removed by abrasion or other mechanical means.

Joint Design

abe Construction Chemicals - Dow Corning Firestop 400 Test Joint ConfigurationsLegend

  1. DOW CORNING Firestop 700 Sealant
  2. Backing material

When designing joints using Dow Corning Firestop 700 Sealant, the minimum width should be 6mm. For joints between 6–12mm wide, a seal depth of 10mm is recommended.

Attainment of specific fire ratings is dependent on the joint configuration. Detailed information is given in Table 2. (refer to datasheet)

Expansion joint types that have been tested are shown in Figure 1. The type of joint selected will depend on fire requirements for the project and aesthetics of the building.

For additional information or assistance, please contact the technical services department.

Penetration Design

DOWSIL FIRESTOP 700 Sealant has been developed for use in small penetration seal applications where it should be used in conjunction with specified backing material.

DOWSIL FIRESTOP 700 Sealant can also be used in conjunction with other Firestop products such as DOWSIL™ FIRESTOP 800 Self Leveling Silicone. Please consult the relevant data sheets for further information.

For larger penetrations, DOWSIL™ 3-6548 RTV Silicone Foam should be used.

Attainment of specific fire ratings is dependent on the joint configuration. Detailed information is given in the Fire rating Tables 3, 4 and 5.
Figure 2: Typical service penetration. Cable penetration. (refer to technical datasheet)

Handling Precautions

Product Safety Information required for safe use is not included. Before handling, read product and safety data sheets and container labels for safe use, physical and health hazard information. The safety data sheet is available from your local Dow sales representative.

Usable Life & Storage

When stored in cool, dry conditions below 30°C in the original unopened containers DOWSIL FIRESTOP 700 Sealant has a usable life of 12 months from the date of production.


DOWSIL FIRESTOP 700 Sealant is available in 310 ml cartridges packed in boxes of 12 and 20 liter pails.


DOWSIL FIRESTOP 700 Sealant should not be used against substrates that bleed oils, plasticizers or solvent. Consult the technical service department for further advice in specific applications.

DOWSIL FIRESTOP 700 Sealant is not intended for use as the structural seal in any application.

This product is neither tested nor represented as suitable for medical or pharmaceutical uses.

Health & Environmental Information

To support customers in their product safety needs, Dow has an extensive Product Stewardship organization and a team of Health, Environment and Regulatory Affairs specialists available in each area. For further information, please consult your local Dow representative.

Limited Warranty Information – Please read carefully

The information contained herein is offered in good faith and is believed to be accurate. However, because conditions and methods of use of our products are beyond our control, this information should not be used in substitution for customer’s tests to ensure that our products are safe, effective, and fully satisfactory for the intended end use. Suggestions of use shall not be taken as inducements to infringe any patent.
Dow’s sole warranty is that our products will meet the sales specifications in effect at the time of shipment.

Your exclusive remedy for breach of such warranty is limited to refund of purchase price or replacement of any product shown to be other than as warranted.

TABLE 1: Estimating sealant requirements
TABLE 2: Fire rating Test Reports J82973/1 and J86464/1
TABLE 3: Fire rating Test Report J82973/2
TABLE 4: Fire rating Test Report 86K40074B