Seamless integration with your waterproofing system is critical. Hi-Flex 50 ensures your flexible seals and bond breakers perform without compromise. This MS Polymer sealant delivers the high movement capability and robust adhesion needed to prevent system failure. It maintains waterproofing integrity across crucial joints and transitions. Expect durable, flexible seals that last.

Why this product exists

Hi-Flex 50 was engineered as a high-performance, flexible MS Polymer sealant specifically for the Adheseal Everflex waterproofing membrane range. It creates an ideal bond breaker and sealant that prevents system incompatibilities. This formulation ensures long-term waterproofing integrity, offering superior flexibility, UV and weathering resistance, and outstanding primeless adhesion across a range of substrates. It resists gassing and bubbling, even in humid conditions.

The numbers that matter

  • Movement Capability: +/- 25% (ASTM C719). This ensures movement joints can expand and contract without compromising the seal. A 10mm joint can handle 2.5mm of movement in either direction, maintaining integrity.
  • Cure Rate: 3.0mm per 24 hours. This allows for efficient project timelines, letting you proceed with subsequent trades sooner while still providing sufficient tooling time immediately after application.
  • Non-Staining (ASTM C510) and Non-Gassing. Prevent unsightly discolouration or bubbling on finished surfaces, a common call-back issue for lesser sealants, especially in humid conditions.
  • Hardness Shore A: 35 (ASTM D2240). This moderate hardness provides a balance of flexibility and durability, allowing the sealant to absorb movement while resisting damage from incidental contact.

What it's like to use

Hi-Flex 50 is easy to gun, non-slump, and tools smoothly. Apply it within temperatures of 5°C to 40°C. Tool immediately after application, within 10 minutes, using a moistened spatula for a smooth finish. For cleanup, wet sealant and tools respond to Xylene. Remove cured sealant mechanically or by softening with solvent and scraping. For skin cleaning, use Adheseal Hand Wipes.

Surface preparation is key. Ensure all surfaces are sound, dry, and clean. For non-porous substrates like aluminium or waterproof membranes, roughen lightly then clean and pre-treat with Adheseal 50A Surface Prep. For porous substrates like concrete or brick, prime with Everflex Supaprime Sealant Primer. Always control joint depth with a compatible backer rod to prevent three-sided adhesion.

Where this product excels

  • Balconies, podiums, door/window reveals, and flashings. Use Hi-Flex 50 as a critical bond breaker or sealant for cracks and joints, integrating seamlessly with Everflex waterproofing membranes or used with latex bonding agents.
  • Concrete and membrane-covered tiled roofing. This sealant acts as a bond breaker and crack filler, often specified after an epoxy primer and beneath a UV stable roof membrane, ensuring flexible, weather-resistant protection.
  • Wet areas including bathrooms, showers, and laundries. Use Hi-Flex 50 as a bond breaker or fillet sealant to support Everflex waterproofing membranes. Finish with a compatible silicone sealant like Adheseal S100 Sanitary Silicone Sealant where aesthetic considerations are primary.
  • General construction sealing and lightweight component adhesion. Its versatile adhesion and non-corrosive properties make it suitable for a wide range of tasks, from sealing joints in prefabricated panels to bonding fibreglass or display signs.

How it fits in a real system

Hi-Flex 50 commonly functions as the final flexible seal within multi-stage waterproofing systems. For example, in parapet and hood assemblies, it follows the application of Everflex VBS Bitumen Primer and Everflex WPUV UV-Stable Waterproofing Membrane membranes, creating a durable and flexible finish layer before any topcoat. This ensures all critical movement joints and transitions are sealed, preventing water ingress at vulnerable points in the build-up. Its proven compatibility with the Everflex range makes it a reliable choice for system integrity.

Choose this when

  • When you require a high-performance bond breaker or flexible sealant within Adheseal Everflex waterproofing membrane systems.
  • When the application demands high movement capability (up to +/- 25%) and excellent UV/weathering resistance.
  • When you need a non-staining, non-gassing sealant for critical aesthetic and performance areas like balconies, facades, or roof perimeters.
  • When you need primeless adhesion to a broad range of construction substrates, including powder-coated metals and waterproof membranes.

Don't use this when

  • Not for: Long-term continuous water immersion or internal swimming pool applications due to exposure to high chlorine levels.
  • Not for: Totally confined spaces; it requires atmospheric humidity to cure.
  • Not for: Structural glazing. For this, consider a dedicated glazing silicone like N-80 or N-60.
  • Not for: All stone applications without prior stain testing. For marble or granite, Adheseal S100 Sanitary Silicone Sealant may be suitable after testing.
  • Not for: Use on bituminous, natural rubber, EPDM rubber surfaces, or with compounds that leach oils, plasticisers, or solvents.
  • Not for: Heavy-duty concrete expansion joints; for this, consider Adheseal PU25 Fast-Cure Polyurethane Sealant.

Hi-Flex 50 is formulated to be non-toxic and low VOC (1.5% USEPA), meeting Green Star environmental criteria. This supports healthier indoor air quality and sustainable building practices.

Choosing your flexible Adheseal sealant

When selecting a flexible sealant from the Adheseal Hi-Flex family, consider the specific demands of your project. Choose Hi-Flex 50 for its superior flexibility (+/- 25% movement), excellent UV and weathering resistance, and critical compatibility as a bond breaker with Adheseal Everflex waterproofing membranes. Its non-staining and non-gassing properties are ideal for applications where appearance and long-term integrity matter, particularly in humid or exposed conditions. If your project does not require these specific waterproofing system compatibilities or high-performance attributes, other Hi-Flex products may offer a different balance of properties.