DESCRIPTION

Sikalastic® M 645 is a unique, single component, liquid applied polyurethane membrane used for waterproof­ ing and protection of concrete, metal and fiber-based cement substrates.The product can be easily applied in thick layers without bubbles and forms a hydro­ phobic, elastic, seamless membrane without joints that protect old and new structures efficiently.It can be applied by trowelsqueegee or airless spray gun in two coats

USES

Sikalastic® M 645 is used as a waterproofing or damp­ proofing membrane for concrete protection with ex­ cellent crack bridging property. It is suitable for both new and refurbishment projects and recommended for use in the folfowing areas:

  • Waterproofing for exposed roofs with topcoat
  • Balconies, Terraces, Podium, Roofing, Pedestrian Traffic area
  • Light roofing made of metal or fibrous cement
  • Refurbishment on existing bitumen sheet membrane
  • Protection of PU foam

CHARACTERISTICS/ ADVANTAGES

  • One-component ready to use
  • Simple application by trowel, squeegee or airless spray system
  • High thickness build-up per one layer- Less applica­tion layers required and reduces application time and cost
  • Seamless membrane without joints
  • Highly elastic and crack-bridging
  • Excellent mechanical properties – No reinforcement required except for detailing
  • Cold Weather resistance – The film remains elastic down to -35°C.
  • High temperature resistance – The film will not soften with service temperature up to 80°C.
  • Special primers available for almost all substrates
  • Easy repair and maintenance in case of physical dam­ age to membrane

PRODUCT INFORMATION

Packaging: Sikalastic® M 645 is available in 22.5 kg and 25kg pails

Shelf life: 9 months from date of production

Storage conditions: Store in original unopened packaging in a dry and shaded area

Appearance / Colour: Liquid

Density: 1.28 – 1.34 g/ml or 1280-1340 kg/L

Solid content by weight: 2>:85%

Viscosity: 5000-9000 cps (Brookefield Vitescomerj)

TECHNICAL INFORMATION

Shore A hardness: 70-80,7 days (ASTM D2240)
Tensile strength: 6 MPa (7 days) Tensile Strength retention after heat ageing,80 °C/168hrs (ASTM D4587)
Elongation at break: 450 % (Elongation at break), 7 days (ASTM D412)

Crack bridging ability: AS (2.5mm), Static, 7 days at – 20111 (EN 1062-7)

Tensile adhesion strength:1.0 Mpa (7 days), Pull Out (ASTM D 7234)
Tear strength: 30 N/mm,7 days (ASTM D624)
Flexibility at low temperature: No cracks at – 2s·c, 7 days (ASTM D 1970)
Heat resistance: Extensibility after heat ageing – No cracking (ASTM C1522)
Water absorption: 5%,7 days immersion (ASTM D570)
Water penetration under pressure: No cracks, 7 days (up to 7 Bar, 71.4meter) (ASTM D 5385)
Water vapour transmission: 21.6 g/m2/24h, 7 days (ASTM E96)

APPLICATION INFORMATION

Consumption: The consumption depends on the application and design thickness. For 1.5 mm dry film thickness approximately 2.4kg/m2 is required.The consump­ tion is theoretical and can vary according to the absorption and roughness of the support. It is essential to carry out representative trials on site to evaluate the exact consumption

Ambient air temperature: +10 °C min. / + 35 °C max.

Relative air humidity: Upto 80%

Dew point: Beware of condensation. The substrate and uncured applied membrane must be at least +3 °C above dew point

Substrate temperature: +10 °C min./+ 35 °C max.

Substrate moisture content: 4 % parts by weight.

Tack free time: 12 hrs (at 23°C / 50%), touch dry 

Waiting time/ Overcoating: 12 hrs min./ 48 hrs max (at 23°C / 50%) 

Applied product ready for use: 7 days (Full cure)

BASIS OF PRODUCT DATA

All technical data stated in this Product Data Sheet are based on laboratory tests. Actual measured data may vary due to circumstances beyond our control.

ECOLOGY, HEALTH AND SAFETY

User must read the most recent corresponding Safety Data Sheets (SDS) before using any products. The SDS provides information and advice on the safe handling, storage and disposal of chemical products and con­ tains physical, ecological, toxicological and other safety-related  data.

APPLICATION INSTRUCTIONS

SUBSTRATE PREPARATION

All substrates (new and old) must be structurally sound, dry, and free of laitance and loose particles. Clean of oil, grease, rubber skid marks, paint stains and other adhesion impairing contaminants. Profile mechanically the surface by shot blasting, high pres­sure water jetting or other suitable mechanical pre­paration method.

After surface preparation the tensile strength of the substrate should exceed 1.5 N/mm2 (check with an ap­ proved pull-off tester). Temperature of the substrate should be minimum +lOQC and maximum +35QC. The residual moisture content of the substrate must not exceed 4% (check with e.g. CM device). The temperat­ ure of the substrate must be at least 3QC above the current dew point temperature.

Do not apply the Sikalastic®M 645in temperature be­ low +10°C, or when dew, rain or frost is imminent within the next 48 hours.

SUBSTRATE QUALITY/ PRE-TREATMENT

Priming

Before applying membrane, the substrate must be sealed by primer.

Use a suitable primer for Sikalastic® M 645 on con­ crete,metal or bituminous surfaces (Consult our Tech­ nical Services team for selecting the most appropri­ ate primer)

Also, possible to use MasterSeal M 645 as self-primer by adding 5% xylene to dilute.

On Concrete

Before the surface application, all detail areas and any singular points like wall-floor connections, chimneys, joints, substrate cracks, penetrations, corners, etc, must be treated. For this , apply one layer of Sikalast­ ic®M 645 then place a correct cut stripe of geotextile mat (80 ~1oog/m2) into the wet material. Press in to fully soak without leaving air pockets.Then fully satur­ ate the geotextile mat by applying additional Sikalast­ ic® M 645. All lap joints in the mat reinforcement should be minimum 50mm.

When the final membrane is applied, the overall thick­ ness over joints and cracks, at coves and around pen­etrations should be approximately 2.0 mm on the standard system.

APPLICATION

Membrane Application Directly On Substrate

Sikalastic® M 645 can be applied easily with trowel, squeegee or spray equipment (like Graco XHD00l spray machine, Max 500 bar, material be heated to ~ 40 degree)

One layer can reach 1.0 mm DFT without bubbles.

Mix homogenously Sikalastic® M 645 by using a slow speed (approx. 300 -500 rpm) hand-held mixing machine fitted with a mixing paddle. Premark the area based on consumption and Dry Film Thickness re­ quired. Pour mixed Sikalastic® M 645 onto the primed substrate and spread with trowel or squeege or spray equipment at a consumption of 1.2 kg/m2 per layer.

Membrane Application Using Reinforcement

Mix homogeneously Sikalastic® M 645 with mechanic­ al stirring before use.

After the mixing, pour the product onto the primed surface to be waterproofed, and spread with trowel or squeegee at a minimum consumption of 1.2 kg/m2 per layer. Lay geotextile mat (80-100g/m2) reinforcement into the wet membrane, press in and flat with trowel or squeegee to fully saturate the geotextile mat. All lap joints in the geotextile mat reinforcement should be minimum 50mm.

lmmediat ly pour Sikalastic®M 645 again on the geo­ textile mat and spread out at consumption of 1.2 kg/m2 per layer, until full saturation. As per thickness design, apply one more layer to achieve final thick­ ness.

Sikalastic® M 645 can also be sprayed by airless spray equipment.

 

UV Resistant Top-Coat

Sikalastic® M 645 doesn’t have sufficient UV and weather resistance to be used in exposed applications without protection for long term. In exposed applica­ tions, apply two coats of a UV Resistant top coat for long term UV stability and protection (Consult our Technical services for recommendation on a suitable top coat)

 

LEGAL NOTES

The information, and, in particular, the recommenda­ tions relating to the application and end-use of Sika products, are given in good faith based on Sika’s cur­ rent knowledge and experience of the products when properly stored, handled and applied under normal conditions in accordance with Sika’s recommenda­ tions. In practice, the differences in materials, sub­ strates and actual site conditions are such that no war­ ranty in respect of merchantability or of fitness for a particular purpose, nor any liability arising out of any legal relationship whatsoever, can be inferred either from this information, or from any written recom­ mendations, or from any other advice offered. The user of the product must test the product’s suitability for the intended application and purpose. Sika re­ serves the right to change the properties of its products. The proprietary rights of third parties must be observed. All orders are accepted subject to our current terms of sale and delivery. Users must always refer to the most recent issue of the local Product Data Sheet for the product concerned, copies of which will be supplied on request.