Not sure on how much sealant you'll need? Use our calculator to find out.
For sealing construction joints, prefabricated concrete panels, and forming critical bond breakers under waterproofing membranes, Hi-Flex 50 Hybrid MS Polymer Sealant provides primeless adhesion and high movement capacity without the risk of gassing or bubbling, even in high humidity.
Hi-Flex 50 is a neutral-cure, moisture-curing MS Polymer hybrid sealant that combines elastomeric flexibility with high UV and weathering resistance. The formulation cures by reacting with atmospheric humidity to form a permanently elastic joint seal. Because it contains no isocyanates, solvents, or acids, it is non-corrosive to galvanized steel, zinc-coated steel, and concrete. It incorporates biological inhibitors to resist mould and fungal growth in hot, humid environments, and is compatible with Adheseal Everflex membranes including Aqua-Ban, WPM, WPUV, and SMP.
Hi-Flex 50 adheres to most common building materials without staining or bleeding. Suitable substrates and applications include:
Joints should maintain a 2:1 width-to-depth ratio. Internal joints require a minimum width and depth of 5mm, while external joints require a minimum width of 12mm. For joints deeper than 10mm, insert an open-cell backer rod 25% larger than the joint width. If using a closed-cell backer rod, do not damage its outer skin, as punctured closed-cell backing can cause gassing and bubbles in the curing sealant.
For porous substrates such as concrete, aerated concrete, bricks, and mortars, prime with Everflex Supaprime. For non-porous metals and plastics, slightly roughen the surface and pre-treat with Adheseal 50A surface prep. Allow primers to dry for at least 30 minutes but no more than 2 hours before gunning the sealant.
When used as an adhesive, apply a triangular bead by holding the nozzle at 90° to the surface. Compress the adhesive bead to no less than 2mm thickness to ensure adequate wet transfer and bond-area contact.
Yes, it is designed for compatibility. Hi-Flex 50 works as a bond breaker and fillet sealant with Adheseal Everflex Aqua-Ban, WPM, WPUV, and SMP membranes.
Hi-Flex 50 is non-staining as per ASTM C510. However, for all stone applications, a preliminary stain testing program is recommended. For marble and granite, Adheseal S100 is typically recommended after testing.
No, Hi-Flex 50 is not for internal swimming pool applications. It should not be exposed to high levels of chlorine or long-term water immersion.
Hi-Flex 50 provides a movement capability of up to +/- 25%. This rating is confirmed by ASTM C719 testing, making it suitable for dynamic construction joints.
No, it is resistant to gassing. The formulation is designed to eliminate bubbling even in high humidity applications, ensuring a clean finish.
| Application | Key benefit | Primary trades |
|---|---|---|
| Bond breaker for waterproofing membranes | Ensures flexible joints compatible with Everflex membranes, preventing stress points and membrane failure. | Waterproofers, Builders |
| Sealing construction joints in facades and panels | Offers +/- 25% movement capability (ASTM C719) with excellent UV and weathering resistance, maintaining a durable, flexible seal. | Builders, Commercial Facade Contractors |
| Sealing joints in prefabricated buildings or concrete panels | Provides a permanently elastic and dustproof seal with strong adhesion, accommodating differential thermal movement. | Precast Concrete Installers, Builders |
| General perimeter and expansion joint sealing | Resists gassing and bubbling, even in high humidity, and is non-staining (ASTM C510), ensuring a clean, long-lasting finish. | Builders, Tilers, Glaziers |
| Bonding lightweight components and display signs | Achieves strong, primeless adhesion on common building materials including powder coat, fibreglass, and various metals. | Sign Installers, Shop Fitters, Manufacturers |
Ensure substrates are clean, dry, and free from oil, dust, or curing agents. For porous surfaces like concrete, allow a minimum 28-day cure and wipe using a two-cloth method with Xylene. For metal or powder-coated surfaces, lightly abrade and wipe with Adheseal 50A.
Prime using Everflex Supaprime and allow 30–120 minutes drying time before applying sealant.
No primer usually required. Use Adheseal 50A surface prep for metals and waterproof membranes.
Design joints with a 2:1 width-to-depth ratio. Use open-cell backer rod to control sealant depth and avoid three-sided adhesion by using bond breaker tape. Mask joint edges for clean lines if needed.
Min. 5mm width/depth, backer rod recommended above 10mm.
Min. 12mm wide. Ensure UV exposure is considered in dimensioning.
Cut nozzle at 45° angle for joint sealing or 90° for adhesive use. Insert 600ml sausage into a sealant gun and apply a continuous bead, pushing the sealant forward to avoid air entrapment.
Use a 45° nozzle and fill joint fully. Tool within 10 minutes using a moistened spatula for a smooth finish.
Use a triangular bead, approximately twice as high as it is wide. Press surfaces together to compress bead to ≥2mm.
Allow Hi-Flex 50 to cure at a rate of approximately 3mm per 24 hours (25°C, 50% RH). Paintable with acrylic and oil-based paints. Ensure the sealant is fully cured before painting.
Test flexibility of coating. Rigid coatings may crack under joint movement.
Use Xylene for tools while wet. Cured sealant must be removed mechanically.
Wear gloves and safety glasses. Nitrile Rubber gloves are suitable for intermittent contact. Always wash hands before eating, drinking, or using the toilet.
Natural ventilation is adequate under normal use conditions. Ensure proper ventilation in enclosed spaces during application.
Store in a cool, dry, well-ventilated place, out of direct sunlight and away from foodstuffs. Keep containers closed when not in use. Dispose of according to state or local regulations.
Proper surface preparation is crucial for adhesion and long-term performance. This guide outlines requirements for common materials.
Includes aluminium, waterproof membranes, anodized aluminium, stainless steel, PVC, galvanised steel, powder coated metals, and glazed tiles.
Surface prep: Slightly roughen the surface with a fine abrasive pad. Clean thoroughly using the two-wipe process with a suitable cleaner/solvent like Xylene.
Primer: Optional, but recommended for optimal adhesion in critical high-performance applications (e.g., multi-story buildings, highly stressed joints, extreme weather, or water exposure). Use Adheseal 50A surface prep. Apply with a clean cloth and allow 30 minutes to 2 hours before sealant application.
Includes concrete (cured 28 days minimum), aerated concrete, cement-based renders, mortars, and bricks.
Surface prep: Ensure surfaces are structurally sound, dry, and free of dust, loose material, oils, grease, and curing compounds. Substrate must be free from surface water and continual dampness.
Primer: Optional, but recommended for optimal adhesion and long-term performance in critical applications. Use Everflex Supaprime applied by brush. Allow 30 minutes to 2 hours before sealant application. Avoid excessive application to prevent puddling.
For metals like copper, brass, titanium-zinc, and plastics like PVC, an adhesion test is advised. Always perform compatibility tests if contact with potentially incompatible materials is expected.
| Property | Value |
|---|---|
| Product Type | MS Polymer |
| Curing System | Neutral, Moisture Curing |
| Tack-Free Time | 30 minutes @ 25°C, 50% RH |
| Density Specific Gravity | 1.64 +/- 0.05 ASTM D1475 |
| Flammability | Non Flammable |
| Cure Rate | 3.0mm per 24hrs |
| Consistency | Non-Sagging, Smooth Thixotropic |
| Elongation At Break | 200% approx. ASTM D412 |
| Suitable Joint Width | 5 – 50mm |
| Application Temperature | 5°C to 40°C |
| Service Temperature | -40°C to 100°C |
| Movement Capability | +/- 25% ASTM C719 |
| Hardness Shore A | 35 approx. ASTM D2240 |
| VOC | 1.5% (USEPA) |
| Shelf Life | 12 months |
| Staining | Non-staining as per ASTM C510 |
| Colour | Grey (RAL 7047) |
| Packaging | 600ml Sausage |
Here are some common examples on where Adheseal Hi-Flex 50 Hybrid MS Polymer Sealant used by our customers.
