Product Data Sheet Show all documents

Sika® Unitherm® Steel S Exterior

Solvent based fire protection coating for steel, fast dry, interior* / exterior use

Sika® Unitherm® Steel S Exterior is a fast drying, thin film fire protection coating system for interior* and exterior structural steel work. Sika® Unitherm® Steel S Exterior is forming a heat insulating layer under the influence of fire and improves the fire resistance of steel parts like columns, girders and framework.

  • Fast drying intumescent coating
  • Applicable on steel constructions exposed to weathering, the system meets Type X classification
    (i.e. exterior conditions)
  • VOC < 350 g/l
  • Preserves the appearance of a steel construction
  • Applicable to filigree and complex steel building elements
  • Simple application, does not increase static load
  • Individual coloration possible with corresponding topcoat, various colour shades in RAL, others available
Product Data Sheet Show all documents

Usage

For exterior use on structural steel members like columns, girders and framework which are subjected to weathering, high humidity, maritime environment etc. with a highly effective protection to delay the steel from reaching critical temperatures. * For interior use on structural steel members like columns, girders and framework as long as there is no demand for national emission schemes, i.e. German AgBB, etc. Note: With critical situation i.e. frequent formation of condensation and/or heating up of surfaces above + 45°C adequate arrangements should be taken. No topcoat required for dry environments except for a coloured decorative finish.  

Advantages

  • Fast drying intumescent coating
  • Applicable on steel constructions exposed to weathering, the system meets Type X classification
    (i.e. exterior conditions)
  • VOC < 350 g/l
  • Preserves the appearance of a steel construction
  • Applicable to filigree and complex steel building elements
  • Simple application, does not increase static load
  • Individual coloration possible with corresponding topcoat, various colour shades in RAL, others available

Packaging

Sika® Unitherm® Steel S Exterior

25 kg and 5 kg net.

Sika® Unitherm® Thinner

25 l and 5 l

Colour

White

Product Details

Sustainability / Certifications / Approvals

APPROVALS / STANDARDS

Independently fire tested and approved to major European and national standards including:

  • EN 13381-8 (ref: ETA 11/0324)
  • BS 476-20 to 22 (ref: CF 216)
  • DIN 4102-2 (ref: Z-19.11-1319)
  • Solvent based coating for steel protection according to EN 13501-2 and ETAG 018-2, DoP, with CE-mark
  • Certified Green Label product under Singapore Green Building Council (SGBC) Paints & Coatings - Coating, Certificate No. SGBP 2018-1687
 
Product Information

Shelf Life

18 months

Storage Conditions

In originally sealed containers in a cool and dry environment.

Density

~1.31 g/cm3

Flash Point

+ 32°C

Solid Content

~71 ± 3% by volume (according BCF Guidance Methode)

Application

Application Information

Relative Air Humidity

Max. 80 %, application temperature shall be at least ≥ 3 K above dew point.

During application and drying of total Sika® Unitherm® coating system including Sika® Unitherm® Top S topcoat as well as transportation special protection measures must be taken against weathering.

Surface Temperature

Object temperature not below + 5°C, to max. + 40°C*

* If higher temperatures occur, please consult the Technical department for further assistance.

Waiting Time / Overcoating

Sika® Unitherm® Steel S Exterior requires a minimum of 24 hours drying prior to application of topcoat Sika® Unitherm® Top S / Sika® Unitherm® Top S EG.

A complete drying of the fire protection coating prior topcoat application is highly recommended.

Through-drying of Sika® Unitherm® Steel S Exterior can be checked by ‘fingernail-test’.

Prior to further applications possible contaminations must be removed.

Drying Time

Drying / Curing

Average drying time at + 23°C:

Touch-dry< 1 h
Overcoatable~4 h
Dry-to-handle

Depends on the total thickness of Sika® Unitherm® Steel S Exterior

to be applied

Different temperature, different relative humidity's and different fire protection coating thicknesses have an influence on drying time.
Consumption

Consumption

Example:

1000 μm dry ≈ 1350 μm to 1400 μm wet ≈ 1845 g/m2 ≈ 1.408 l/m2


The fire rate of Sika® Unitherm® Steel S Exterior depends on national standard. See corresponding separate consumption table/diagram.

Note: Ratio dry film thickness - wet film thickness varies depending on application method.

Furthermore, proper ventilation is recommended.
Application steps

SURFACE PREPARATION

Blast cleaned steel:
Blast-cleaning to Sa 2 ½ according to ISO 8501-1.
Free from dirt, oil and grease.


Steel with manual de-rusting:
Manual de-rusting (wire brushing or power tool cleaning) according to ISO 8501-1, St. 3.

Galvanized steel:
Free from dirt, oil, grease and zinc salts.
In case of permanent exposure to submersion and condensation surfaces should be sweep blasted according to ISO 12944-4.

Other surfaces:
Tests should be carried out on the specific surfaces.

Please seek further information on info data sheet no. 02 ‘Primers for Sika® fire protection coatings’.

For contaminated and weathered surfaces e.g. galvanized or primed areas we recommend to clean with SikaCor® Wash.

Application to multi coating systems e.g. to accommodate requirements according to ISO 12944-5 (e.g. DFT > 250 μm) are applicable to Sika® Unitherm® Steel S Exterior.

For further information, please consult the Technical Department.

MIXING

Stir thoroughly with slowly turning mechanical stirrer, free of lumps. Addition of thinner is not necessary.

 

APPLICATION

The method of application has a major effect on achieving uniform thickness and appearance. Spray application will give the best results. The indicated dry film thickness is easily achieved by airless spray. In case of application by roller or brush, additional layers may become necessary to achieve the required coating thickness, depending on type of construction, site conditions, colour shade etc. Prior to application a trial on site may be useful to ensure the selected application method will provide the requested results.

Airless spraying:

  • Material shall be applied undiluted
  • Airless machine with pressure ratio ≥ 45 : 1
  • Screens and filters should be removed
  • Hose diameter not below ⅜“
  • Nozzle size 0.46 - 0.66 mm (0.019 - 0.027 inch)
  • Solvent resistant hoses must be used!


By brush and roller:

  • Material shall be applied undiluted
  • Solvent resistant brush or roller must be used


Note: The Sika® Unitherm® Steel S Exterior shall be applied in several coats up to the final dry film thickness required. Wet film thickness max. 400 μm for first application coat on primer. Wet film thickness approx. 750 μm for each subsequent application coat is recommended.

CLEANING OF TOOLS

Immediately after use with Sika® Unitherm® Thinner.

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