Product Data Sheet Safety Data Sheet Show all documents

Sika® Unitherm® Concrete W

Water based fire protection coating system for concrete structures, interior use*

Sika® Unitherm® Concrete W is a water based fire protection coating system for concrete, masonry and brickwork located in interior situations, i.e. not exposed to weathering.
Sika® Unitherm® Concrete W forms an insulating carbon char foam under the effect of heat or fire and protects the concrete substrate against heat and fire.

Protection of concrete, masonry and brickwork against fire or heat
Delays heat transfer through walls in case of fire
Ecological and efficient water based coating, lowest material consumption
Free of halogens and aromatic solvents, VOC < 1 g/l
Meets CO₂ S_D (Class C1) > 50m without any additional coating
Direct application on concrete. No need of primer or scrim
Simple and easy application
Third party approved repair mortars of the Sika MonoTop® range
Individual coloration possible by use of topcoat

Product Data Sheet Safety Data Sheet Show all documents

Usage

Sika® Unitherm® Concrete W is mainly designed for refurbishing/ change of use of building structures like concrete, masonry and brickwork. Sika® Unitherm® Concrete W prohibits the spalling of concrete structures and significantly delays the head build up of steel reinforcements. * In case of semi-exposed or exposed areas (Type Y and X) please contact the technical department for further consulation.

Advantages

Protection of concrete, masonry and brickwork against fire or heat
Delays heat transfer through walls in case of fire
Ecological and efficient water based coating, lowest material consumption
Free of halogens and aromatic solvents, VOC < 1 g/l
Meets CO₂ S_D (Class C1) > 50m without any additional coating
Direct application on concrete. No need of primer or scrim
Simple and easy application
Third party approved repair mortars of the Sika MonoTop® range
Individual coloration possible by use of topcoat

Packaging

25 kg net.

Colour

White

Product Details

Sustainability / Certifications / Approvals

SUSTAINABILITY

VOC complient according to German AgBB and to French Decrete No. 2011-321 (A+)

APPROVALS / CERTIFICATES

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

ETA-18/1152
EN 13381-3:2015 including Annex A, smouldering fire
EN 1062-1, table 7

Product Information

Shelf life

18 months

Storage conditions

In originally sealed containers in a cool and dry environment.

Protect against frost!

Density

~1.4 g/cm³

Flash point

Not applicable

Solid content

~76 % ± 3 by volume (according to BCF Guidance Method)

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® topcoats special protection measures must be taken against weathering.

Furthermore, proper ventilation is recommended.

Surface temperature

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

* If higher temperatures occur, please consult the technical department forfurther assistance.

Waiting time to overcoating

Prior to further applications possible contaminations must be removed.

Sika® Unitherm® Concrete W requires a minimum of 12h drying prior to application with itself.

Sika® Unitherm® Concrete W requires a minimum of 24h drying prior to application of topcoats Sika® Unitherm® Top W, Sika® Unitherm® Top S / Sika® Unitherm® Top S EG and Sikagard-675 W.

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

Through-drying of Sika® Unitherm® Concrete W can be checked by ‘fingernail-test’.

Drying time

Drying/Curing

Approx. 24 h after application of last coat at + 20°C object temperature and 60 % relative humidity.

Different temperatures, different relative humidity and different coating thicknesses have an influence on drying time.

Drying stage at + 20°C, 60 % rel. humidty, based on a wet film thickness of 0,500 mm:

Drying stage 1	~10 min
Drying stage 6	~20 min

Consumption

The following table indicates the equivalent concrete (¹) thickness to be substituted by Sika® Unitherm® Concrete W based on different fire resistance periods.

Concrete structure/ concrete type¹	DFT Sika® Unitherm® Concrete W
Coverage range for slabs and walls, one dimensional	0,395 - 0,918 mm
Coverage range for columns and beams, horizontal and vertical orientation	0,395 - 0,917 mm

Exposure period	60 min	90 min	120 min
Equivalent concrete thickness for slabs and walls	20 mm	13mm	17 mm
Equivalent concrete thickness for columns and beams	25 mm	16 mm	12 mm

¹ C30/ 37 concrete type, other concrete types (up to C90/ 105) are available upon request.

The test results are based on EN 13381-3:2015 and the requirements set in EN 1992-1-2 and DIN 4102-4.

Example:

500 μm dry ≈ 650 to 700 μm wet ≈ 910 g/m² ≈ 0.66 l/m²

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

For further information please consult the technical department.

Application steps

SUBSTRATE PREPARATION

Surfaces to be coated must be brushed off and vacuum cleaned afterwards. They have to be solid to support any loads, free of sludge, dirt, oil, grease, wax, water-repellent agents and other contamination. Residual humidity in the concrete must be below 4 % according to CM-humidity measuring instrument.

In case of existing coatings, a compatibility test with the fire protection system is mandatory.

Any damage or imperfection (impact, corrosion, etc.) should be repaired prior the coating with the adequate Sika MonoTop® repair mortar.

MIXING

Stir thoroughly with slowly turning mechanical stirrer, free of lumps.

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: