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Application

  • Top coat for SikaRoof® MTC 12, 15, 18, 22 in both new construction and refurbishment projects.
  • For roofs displaying complex detail areas, even when accessibility is limited.
  • For cost efficient life cycle extension of failing roofs.
  • Highly reflective top coat Sikalastic®-621 TC - SR (traffic white RAL 9016) as part of the Sika SolaRoof™ MTC systems for excellent cool roof characteristics and bi-facial photovoltaic panels.
  • For detailing solutions on singly ply membranes.

Description

A single-component, cold-applied, seamless, highly elastic and UV-stable, moisture-triggered polyurethane top coat (TC) designed to provide easy application and a durable solution as part of the SikaRoof® MTC systems, as well as for detailing on single ply membranes. Suitable for use in hot and tropical climatic conditions.

Features and benefits:

  • Proven technology - over 25-year track record.
  • Single component - no mixing, easy and ready to use.
  • UV-resistant - highly reflective (RAL 9016) and resistant to yellowing.
  • Cold applied - requires no heat or flame.
  • Seamless roof waterproofing membrane.
  • Compatible with Sika® Reemat Premium - easy to detail.
  • Fast curing - free from rain damage almost immediately on application.
  • High elastic and crack-bridging - retains flexibility even at low temperatures.
  • High root resistance.
  • Easily recoated when needed - no stripping required.
  • Good adhesion to most substrates.
  • Vapour permeable - allows substrate to breathe.
  • Strong resistance to common atmospheric chemicals.
  • CE marked.

Applications:

  • Top coat for SikaRoof® MTC 12, 15, 18, 22 in both new construction and refurbishment projects.
  • For roofs displaying complex detail areas, even when accessibility is limited.
  • For cost efficient life cycle extension of failing roofs.
  • Highly reflective top coat Sikalastic®-621 TC - SR (traffic white RAL 9016) as part of the Sika SolaRoof™ MTC systems for excellent cool roof characteristics and bi-facial photovoltaic panels.
  • For detailing solutions on singly ply membranes.

General information
Specification data
Product Reference

Sikalastic®-621 TC

Colour

Shale grey (RAL 8500)

Slate grey (RAL 7015)

Traffic white (RAL 9016)

Special order

Insert requirement, consult manufacturer for information.

Standard product features

Chemical base:

Single-component, moisture-triggered aliphatic polyurethane.

Technical properties:

  • Density (to BS EN ISO 2811-1): 1.41 kg/L (approximate, at 23°C).
  • Reaction to fire (to BS EN 13501-1): Euroclass E (as part of SikaRoof® MTC Systems).
  • External fire performance (to BS EN 13501-5): BRoof (t1) to BRoof (t4) (dependent on SikaRoof® MTC System).
  • Solid content by weight: 81.3% (approximate).
  • Solid content by volume: 87.4% (approximate).
  • Service temperature: -30 to +80°C.
  • Minimum waiting/ overcoating Time: 5°C/ 50% r.h.: 18 hours; 10°C/ 50% r.h.: 8 hours; 20°C/ 50% r.h.: 6 hours.
  • Solar reflectance index (to ASTM 1980): ≥109 (White RAL 9016).
  • Chemical resistance: Salt spray (to ASTM B117): 1000 hours (continuous exposure); prohesion testing (to ASTM G85-94: Annex A5): 1000 hours (cyclic exposure); strong resistance to a wide range of reagents including paraffin, petrol, fuel oil, white spirit, acid rain, detergents and moderate solutions of acids and alkalis. Some low molecular weight alcohols can soften the material. Contact manufacturer for specific information.

Application requirements:

  • Ambient air temperature: 5–35°C.
  • Relative air humidity: 5–85%.
  • Substrate temperature: 5–60°C (≥3°C above dew point).
  • Substrate moisture content: ≤4% (by weight). No rising moisture.

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