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Everflex HVUV: A Technical Overview
Everflex HVUV is a premium elastomeric waterproofing membrane engineered for exposed environments requiring maximum durability and flexibility. Formulated as a single-component, microfibre-reinforced Class III membrane, it forms a fully bonded, seamless barrier that is UV-stable, mould-resistant, and tile-ready. Its high build, rapid recoat time, and compliance to AS4858 & AS4654.1 make it ideal for balconies, roof decks, terraces, and tiled wet areas. The light grey, solar-reflective finish supports energy efficiency and longevity in harsh Australian conditions.
Class III
High Flexibility Rating (AS4858)
Core Features & Specifications
- UV-resistant, Class III membrane with proven long-term exposure stability
- Microfibre reinforced for dimensional stability and crack-bridging capability
- Fast recoat window – 2–4 hours at 25°C and 50% RH
- Fully compatible with popular tile adhesives including RLA C-Mastic & Gripset Unigrip
- Low VOC <2g/L – meets Green Star criteria for indoor air quality
- Single pack – no mixing, ready to roll or brush apply
- Forms a seamless, re-emulsification-resistant membrane
The Everflex HVUV Advantage
- Ideal for exposed balconies, roof decks, and external wet zones
- Supports pedestal systems and tile finishes – easy integration into layered builds
- Quick turnaround on site – minimises delays between coats and before tiling
- Doesn’t re-soften or delaminate – long-term peace of mind in immersion-prone zones
- Fully water-based – safer handling and cleanup on site
Best Practices: Do's & Don'ts
Do
- Use Everflex VBS or WBP primers based on substrate and environment
- Apply in two coats with 0.75mm wet film each, at opposing angles
- Allow 48 hours curing at 25°C before tiling
- Use polyester reinforcing fabric at internal corners and joints
Don't
- Apply under 10°C or over 35°C, or when rain is imminent
- Install over damp, contaminated or uncured substrates
- Use in negative pressure or rising damp conditions
- Expose to heavy foot traffic without protection or slip coat
Applications in Practice: Trade Scenarios
For Waterproofers (On-Site Applicator): External Balconies
The Engineering Challenge
Balconies exposed to full sun and rainfall require a membrane that won’t crack, delaminate, or re-emulsify under tile adhesive. Fast drying between coats is essential for workflow efficiency.
The System-Based Solution with Everflex HVUV
Prepare with Everflex VBS primer. Apply two 0.75mm coats of HVUV with a roller at perpendicular angles. Use reinforcing fabric on joints and corners. Compatible with tile adhesives post 48-hour cure.
Best Practice Note
Use a film gauge to ensure consistent wet thickness, and plan work to avoid coating during rain forecasts. Recoat within 24 hours to maintain adhesion.
For Builders (Business Owner): Rooftop Podium Decks
The Engineering Challenge
Podium decks demand a membrane that meets NCC requirements, resists UV degradation, and bonds permanently to the substrate beneath architectural finishes or pedestal pavers.
The System-Based Solution with Everflex HVUV
Install HVUV over cured concrete (28 days), with VBS primer. Ensure 1.3mm dry film thickness. Finish with LS UV slip coat for added mechanical protection under pavers or podium system.
Best Practice Note
Seal all penetrations and puddle flanges with Hi-Flex MS before membrane application to ensure watertight integration.
Performance Benchmark: Everflex HVUV vs. Standard Alternatives
| Metric | Everflex HVUV | Standard Alternative | Advantage |
|---|---|---|---|
| UV Resistance | Excellent Long-term stability | Moderate | Resists UV degradation, ideal for exposed decks |
| Dry Film Thickness | 1.3mm | 1.0mm | Thicker film improves durability and bridging |
| VOC Content | <2g/L Low VOC | 10–30g/L | Meets Green Star indoor environmental criteria |
Frequently Asked Questions
Can Everflex HVUV be used directly under tiles on balconies?
Yes, Everflex HVUV is suitable for direct under-tile installation in external areas such as balconies and terraces. It provides a Class III flexible waterproofing layer and is compatible with solvent-free adhesives including RLA C-Lite, Gripset Unigrip, and others. Allow a minimum 48 hours cure before tiling.
What primer should I use with Everflex HVUV on concrete?
For cured concrete substrates (minimum 28 days), apply Everflex VBS primer before HVUV. This ensures better penetration and long-term adhesion. On internal areas or less porous surfaces, Everflex WBP primer may be sufficient. Always allow the primer to become touch-dry before applying HVUV.
Is Everflex HVUV suitable for use on timber or plywood?
Yes, Everflex HVUV can be applied to timber flooring including structural Type A PAA JAS-ANZ plywood. Ensure the timber is dry, stable, and securely fixed. Use appropriate primers and seal joints with Hi-Flex MS before membrane application.
How long do I wait between coats of Everflex HVUV?
Recoat time for Everflex HVUV is approximately 2–4 hours at 25°C and 50% relative humidity. Environmental conditions may affect this timing. Always ensure the previous coat is touch-dry before recoating. Do not exceed 24 hours between coats to maintain adhesion.
What is the best way to reinforce corners and joints when using Everflex HVUV?
Apply a fillet bead of Hi-Flex MS in internal corners and over joints. You can also embed a polyester reinforcing fabric into the first wet coat of HVUV for extra strength. Use Elastoband or butyl tape for movement joints and dynamic cracks.
Applications & Benefits
| Application / Use Case | Key Benefit | Primary Trades |
|---|---|---|
| Balconies and Rooftop Decks | UV-stable membrane that won’t re-emulsify, with Class III flexibility for structural movement | Waterproofers, Builders |
| Under Tile Waterproofing | Forms a fully bonded, durable base for solvent-free tile adhesives | Tilers, Builders |
| Wet Area Waterproofing (Showers, Toilets, Laundries) | AS4858 compliant internal waterproofing membrane for residential and commercial jobs | Waterproofers, Plumbers |
| Pedestal Systems / Podiums | Durable waterproof layer compatible with load-bearing tile or paver systems | Commercial Builders, Remedial Contractors |
| External Terraces & Patios | Rapid-drying, low-VOC solution ideal for exposed residential living zones | Builders, Waterproofers |
Applying Everflex HVUV: Enhanced Protocols & Best Practices
-
1. Surface Preparation
Ensure all surfaces are structurally sound, dry, clean, and free from oils, form release agents, laitance, and any contaminants. Fill holes and non-structural cracks with Hi-Flex MS or suitable filler.
Concrete & Screed
Allow concrete to cure for 28 days minimum. Screeds must cure for at least 4 days. Surface must be dust-free and level.
Timber & Sheeting
Timber and sheeting must be securely fixed with no movement. Joints should be sealed and internal corners filleted with Hi-Flex MS.
Timing: Ensure surfaces are completely dry before priming or coating.Pro Tip: Use a moisture meter on concrete and screeds if unsure — HVUV is not designed for damp substrates. -
2. Priming
Select the correct primer based on the substrate type and environmental exposure. Apply using brush or roller.
Everflex WBP
Recommended for internal applications and timber surfaces. Allow to dry until touch-dry before applying membrane.
Everflex VBS
Required for external areas like balconies, roof decks, and pedestal systems. Provides superior bond and vapour barrier.
Timing: Apply membrane within 2–24 hours of primer drying, depending on conditions.Pro Tip: On hot surfaces or porous substrates, priming reduces pinholes and improves film uniformity. -
3. Membrane Application
Mix Everflex HVUV thoroughly before use. Apply with brush or roller in two coats — each perpendicular to the last — to achieve the correct film build.
Coat 1
Apply at 0.75mm wet film thickness. Use a wet film gauge to verify. Allow to dry before recoating.
Coat 2
Apply at right angles to first coat, also at 0.75mm wet film. Ensure minimum dry film thickness of 1.3mm is achieved for external use.
Timing: Recoat within 24 hours. Allow 48 hours full cure before tiling.Pro Tip: Embed polyester reinforcing fabric into wet first coat over joints, penetrations, and corners for added durability. -
4. Detailing & Final Protection
Seal penetrations, puddle flanges, and terminations with Hi-Flex MS. For enhanced protection, especially in exposed areas, apply an optional UV slip-resistant topcoat (e.g., LS UV Coat).
Penetration & Drainage Detailing
Use Hi-Flex MS sealant and install fillet beads where required. Ensure all outlets are recessed and membrane-lapped correctly.
UV Topcoat (optional)
Apply LS UV Slip Coat for long-term durability and added resistance to wear from maintenance traffic or harsh weather.
Timing: Final detailing should be completed after membrane has fully cured (48 hours).Pro Tip: Plan layout to avoid foot traffic over fresh membrane. Use protection boards during follow-up works.
Limitations & Safety
Product Limitations
Do not apply when ambient or substrate temperature is below 10°C or above 35°C.
Not suitable for substrates that are damp, wet, or contaminated with oil, grease, or curing agents.
Not recommended for areas subject to negative hydrostatic pressure or rising damp.
Not designed for heavy foot traffic without additional mechanical protection (e.g. LS slip coat or tiled surface).
Do not expose to rain during curing. Avoid application when rain is imminent.
Safety & Handling Requirements
Personal Protective Equipment
Wear protective gloves, safety glasses, and suitable clothing during application. For extended use, wear coveralls and impervious footwear. Always wash hands thoroughly after use.
Ventilation Requirements
Use in well-ventilated areas. Ensure adequate airflow when working indoors. Avoid inhalation of vapour or mist. Mechanical ventilation may be required for enclosed sites.
Fire & Handling Precautions
Everflex HVUV is water-based and non-flammable. Keep away from open flames and ignition sources when using any adjacent flammable compounds (e.g., sealants or adhesives).
Emergency First Aid
Eyes:
Rinse cautiously with clean water for at least 15 minutes. Remove contact lenses if present and continue rinsing. Seek medical advice.
Skin:
Wash affected area with soap and water. Remove contaminated clothing. If irritation persists, consult a doctor.
Inhaled:
Move the person to fresh air and keep comfortable. If symptoms persist, seek medical attention.
Swallowed:
Do NOT induce vomiting. Rinse mouth thoroughly and seek medical assistance. May cause aspiration if vomited.
Seek medical attention immediately in all cases of serious exposure.
Everflex HVUV Application Guide
Cured Concrete (28 days minimum)
Surface Preparation
Ensure concrete is structurally sound, dry, clean, and free from laitance, oils, or curing compounds. Remove any surface contaminants via mechanical abrasion or pressure wash if necessary.
Primer Requirements
Primer required for external installations
Use Everflex VBS primer on all exposed or porous concrete to promote membrane adhesion and moisture barrier.
Everflex VBSSand-Cement Screed (3:1)
Surface Preparation
Allow screed to cure for a minimum of 4 days. Ensure dry, dust-free surface. Fill imperfections and voids before applying membrane.
Primer required before membrane application
Prime with Everflex VBS or WBP depending on exposure and porosity. For external or wet zones, use VBS.
Everflex VBS or WBPMasonry / Render (minimum 4 days cured)
Surface Preparation
Clean and dry surface thoroughly. Remove efflorescence, loose debris, and ensure flatness. Fill any cracks or holes with appropriate patching compound or Hi-Flex MS sealant.
Primer required
Use Everflex WBP for internal or low-exposure areas. For exterior exposure, apply Everflex VBS.
Everflex VBS / WBPFibre Cement Sheet / Villaboard
Surface Preparation
Ensure sheets are securely fastened and joins are sealed. All dust and debris must be removed. Use Hi-Flex MS or bond breaker tape at sheet joins and internal corners.
Primer optional on dry, clean surfaces
If surface is slightly porous or exposed to sunlight, prime with Everflex WBP for added adhesion.
Everflex WBPTimber / Structural Plywood (Type A, PAA JAS-ANZ)
Surface Preparation
Ensure plywood is Type A bonded and well supported. Surface must be clean, dry, and free of oils or wax. All joints must be sealed using Hi-Flex MS or reinforced with banding tape.
Primer required for reliable adhesion
Use Everflex WBP for all timber substrates before membrane application.
Everflex WBP
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