Sikalastic®-641

• Conformity with LEED v4 MRc 4 (Option 2): Building Product Disclosure and Optimization - Material Ingredients

• BRE Environmental Product Declaration (EPD)

• CE Marking and Declaration of Performance to ETA 14/0177

• European Technical Assessment ETA 14/0177 based on ETAG 005 Part 1 and 6 - Liquid-applied roof waterproofing using kits based on polyurethane

• External Fire Exposure to Roofs - 10 Year System BS 476 Part 3: 2004, Sikalastic®-641, Exova, Test report No. 336139

• External Fire Exposure to Roofs - 10 Year System DD CEN/TS 1187:2012 Test 1, Sikalastic®-641, Exova, Test report No. 336143

• External Fire Exposure to Roofs - 25 Year System BS 476 Part 3, Sikalastic®-641, Exova, Test report No. 336140

• External Fire Exposure to Roofs - 25 Year System DD CEN/TS 1187:2012 Test 1, Sikalastic®-641, Exova, Test report No. 336141

• Fire Testing with Burning Brands, Wind and Radiant Heat- 10 Year System DD CEN/TS 1187:2012 Test 4, Sikalastic®-641, Exova, Test report No. 336142

• Fire Testing with Burning Brands, Wind and Radiant Heat- 25 Year System DD CEN/TS 1187:2012 Test 4, Sikalastic®-641, Exova, Test report No. 336141

• Odour comparison Sikalastic®-641, Odournet, Report No. 456-2014-17

• Odour comparison Sikalastic®-641, Odournet, Report No. 456-2014-19

• Reaction to Fire - 25 Year System EN 13501-5: 2007 + A1: 2009, Sikalastic®-641, Exova, Classification report No. WF 336207

• Roof Coverings Exposed to External Fire - 10 Year System EN 13501-1: 2005 + A1: 2009 Test 4, Sikalastic®-641, Exova, Classification report No. WF 336203

• Roof Coverings Exposed to External Fire - 10 Year System EN 13501-1: 2005 + A1: 2009, Sikalastic®-641, Exova, Classification report No. WF 336206

• Roof Coverings Exposed to External Fire - 10 Year System EN 13501-5: 2005 + A1: 2009, Sikalastic®-641, Exova, Classification report No. WF 336204

• Roof Coverings Exposed to External Fire - 25 Year System EN 13501-1: 2005 + A1: 2009 Test 4, Sikalastic®-641, Exova, Classification report No. WF 336202

• Roof Coverings Exposed to External Fire - 25 Year System EN 13501-5: 2005 + A1: 2009, Sikalastic®-641, Exova, Classification report No. WF 336205

Aliphatic polyurethane

9 months from date of production

The product must be stored in original, unopened and undamaged sealed packaging in dry conditions at temperatures between +0 °C and +25 °C. Always refer to packaging.

~1.42 kg/l

Value +23°C

~88.0 %  (+23 °C / 50 % r.h.)

~84.0 % (+23 °C / 50 % r.h.)

Refer to System Data Sheet:

• Sikalastic®-641 Economic System

• Sikalastic®-641 Standard System

• Sikalastic®-641 Enhanced System

• Sikalastic®-641 Premium System

• Sikalastic®-641 Premium Fleece System

• SikaRoof® i-Cure-12

• SikaRoof® i-Cure-15

• SikaRoof® i-Cure-18

• SikaRoof® i-Cure-22

B_Roof (t1) + (t4) over Build up roofing system

≥ 108^*

*  All values refer to the initial (properly cured, non-weathered) status of Sikalastic®-641 white (RAL 9016).

-30 °C to +90 °C

It is recommended the product is stored under warm conditions (+20 °C) prior to application at temperatures below +10 °C.

+5 °C min / +40 °C max

20 % r.h. min / 85 % r.h. max

Beware of condensation. The substrate and uncured applied product must be at least +3 °C above dew point to reduce the risk of condensation or blooming on the surface of the applied product.

+5 °C min. / +60 °C max.

The product can be applied on substrates with a moisture content of ≤ 4 % part by weight. The substrate must be visibly dry with no standing water.

The following test methods can be used to determine the substrate moisture content:

• Sika®-Tramex meter

• CM-measurement

• Oven-dry-method

No rising moisture according to ASTM (Polyethylene-sheet).

~1 hour (+20 °C / 50 % r.h.)

Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.

Material in opened containers must be applied immediately. In opened containers, the material will form a film after ~1 hour.

1  After four days, the surface must be cleaned and primed with Sika® Reactivation Primer before continuing.

Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.

1  Be aware that the impact of heavy rain or rain showers can physically mark or damage the still liquid membrane.

2  Application at higher than recommended film thicknesses may result in a prolonged “soft” feel to the coating. This will eventually cure.  

Note: Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.

General

All dust, loose and friable material must be completely removed from all surfaces before application of the product and associated system products, preferably by vacuum extraction equipment.

To confirm adequate surface preparation and Sikalastic®-641 adhesion, carry out a preliminary trial before full application together with adhesion tests as required.

Concrete and Cementitious substrates

Substrate must be structurally sound, clean, dry and free of all contaminants such as dirt, oil, grease, coatings, laitance, surface treatments and loose friable material.

New concrete should be cured for at least 28 days.

Substrates must be prepared mechanically using suitable substrate preparation equipment to remove cement laitance and achieve an open textured gripping surface profile suitable for the product thickness.

High spots can be removed by grinding.

Weak cementitious substrates must be removed and surface defects such as blow holes and voids must be fully exposed.

Repairs to the substrate, filling of joints, blowholes/voids and surface levelling must be carried out using appropriate products from the Sikafloor®, Sikadur® and Sikagard® range of materials. Products must be cured before applying Sikalastic®-641.

Brick and stone

Thoroughly clean by power wash and allow to dry. Where there is a risk of algal re-growth on absorbent surfaces use Sika Biowash. Refer to the individual Product Data Sheet. Repair any spalling, flaking or other damage and replace any missing jointing.

Ceramic tiles

Tiles must be sound and bonded securely to the substrate, remove as required if damaged or unbonded. Power wash and use Sika® Biowash as required.

Asphalt

Thoroughly clean by power wash and allow to dry. All major cracks should be sealed to allow continuity of the Sikalastic®-641 system. Asphalt must be carefully assessed for moisture and/ or air entrapment, grade and surface finish prior to any coating works being carried out. Any priming requirement must also be considered.

Bituminous felt

Felt must be firmly adhered or mechanically fixed. Thoroughly clean by power wash and allow to dry. Treat blisters by star cutting and removing any underlying water. Allow to dry and re-adhere using Decostik® SP. Badly degraded areas should be replaced with Carrier Membrane bonded with Decostik® SP.

Single ply

Various types of single ply sheeting can be coated. Contact Sika Technical Services for additional information.

Bituminous coatings

Bituminous, volatile mastic or old coal tar coatings must be rigid and without a sticky surface. Remove loose, degraded and tacky coatings.

Metals

Ferrous metals must be in a sound surface condition. Surfaces must be clean, free from rust, oil, grease, existing loose or degraded coatings etc. Prepare surfaces to a bright metal finish using suitable preparation techniques taking into account environmental conditions.

Non-ferrous metals must be in a sound surface condition. Remove any deposits of dust and oxidation and abrade to a bright metal finish. Wire brushing can be used for soft metals such as lead. Surfaces must be clean, free from oil and grease, which, if present, must be removed with a proprietary de-greasing solution. Then wash with detergent, rinse and dry.

Wood

Wood and wood based panel roof decks must be in good structural condition, firmly adhered or mechanically fixed.

Wood based decks require a complete layer of Carrier Membrane SA before the application of the chosen Sikalastic®-641 system. The substrate must then be treated as a felt roof. Small timber protrusions must be flattened by locally planing or sanding to provide a smooth surface.

Paints/Coatings

Remove loose or degraded coatings by suitable preparation techniques to provide a feathered firm adhering edge. Remaining coatings can be overcoated if soundly adhered. Ensure the surface is clean and free from oil, grease etc.

Existing Sikalastic®-641 system

Clean the membrane surface using a power wash at ~14 N/mm² (2000 psi) including detergent then rinse thoroughly and allow to dry.

Sikalastic®-641 is supplied ready for use. Before application, mix for a minimum of 1 minute using mixing paddle and drill or other suitable equipment to mix the liquid and all the coloured pigment until a uniform colour has been achieved. Over mixing must be avoided to minimise air entrainment.

Reference must be made to further documentation where applicable, such as relevant method statement, application manual and installation or working instructions.

General

Always begin application with detailing before installation of the main horizontal surfaces.

Primer

Pour the appropriate mixed primer onto the prepared substrate and apply by brush or appropriate roller. Ensure a continuous, pore free coat covers the substrate. Confirm primer waiting /overcoating time has been achieved before applying successive products. Refer to individual primer Product Data Sheet.

Base coat

Pour mixed Sikalastic®-641 onto prepared substrate the same width as the Sika® Reemat Premium and apply evenly by brush (soft nylon or bristle brush) or roller (short pile mohair roller) at the required consumption rate in 2 directions at right angles to each other.

Reinforcement

Roll in the Sika® Reemat Premium reinforcement whilst Sikalastic®-641 is still wet ensuring there are no bubbles or creases in the reinforcement. Reinforcement overlaps must be a minimum of 50 mm. Recommendation is to work 1.0 m at a time lengthways applying 1st coat and embedding reinforcement.

Top coat

Pour mixed Sikalastic®-641 onto the applied reinforcement layer and apply evenly by brush or short piled roller at the required consumption rate in 2 directions at right angles to each other. Confirm overcoating times before application.

Ensure each application / coat is clean and dry before applying next coat.

Note: Material will dry on the surface in around 30 minutes depending on temperature and humidity conditions. Always maintain a wet edge and finish surface as work proceeds. Returning to re-work areas that are partially dried may damage the surface.

Clean all tools and application equipment with Thinner C immediately after use. Hardened material can only be removed mechanically.