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Everflex WPUV: A Technical Overview
Everflex WPUV is a premium-grade, water-based polyurethane membrane designed for UV-exposed waterproofing applications. Engineered as a self-reinforced, Class 3 elastomeric membrane, it forms a seamless, flexible barrier over substrates such as concrete, screed, FC sheet, and structural plywood. Highly durable and resistant to ponding water, microbial growth, and weathering, it complies with AS-4858 and AS-4654.1. Everflex WPUV is low-VOC, non-flammable, tile adhesive compatible, and suitable for both internal and external waterproofing projects including under-tile installations and rooftops under pedestal systems.
300%+
Elongation (Class III Rated)
Core Features & Specifications
- UV resistant: formulated for fully exposed external applications
- Class III flexibility: exceeds 300% elongation with high recovery
- Low VOC: Green Star compliant with <2 g/L VOC
- Compatible with tile adhesives: proven bond with RLA & Gripset systems
- Does not re-emulsify: provides long-term performance even under immersion
- Water-based: easy cleanup with water before curing
- Reinforced: microfibre-enhanced for strength and crack resistance
- Service temp range: -40°C to +80°C
The Everflex WPUV Advantage
- Forms a seamless, bonded waterproof barrier that withstands water ponding and UV exposure
- Backed by test certifications to AS4858:2004 and AS4654.1:2012
- Available in light grey with optional tinting for aesthetic integration
- Achieves required DFT in just two coats; fast recoat (2–4 hr) and cure time (48 hr before tiling)
- Safe for use in residential, commercial, and multi-storey applications
Best Practices: Do's & Don'ts
Do
- Use primer (Everflex WBP or VBS) on porous or external surfaces
- Apply a minimum of two coats perpendicular to each other
- Reinforce corners and joints using Adheseal Elastoband or Butyl Tape
- Use film thickness gauge to confirm 1.0–1.3mm DFT
Don't
- Don’t apply on wet, damp, or contaminated substrates
- Don’t use when rain is imminent or below 10°C ambient temperature
- Don’t use on surfaces subject to rising damp or negative pressure
Applications in Practice: Trade Scenarios
For Waterproofers (Residential Projects): Rooftop Balcony Over FC Sheet
The Engineering Challenge
Client requires a seamless membrane under tiles for a balcony exposed to full sun, seasonal rain, and occasional foot traffic.
The System-Based Solution with Everflex WPUV
Primed with Everflex VBS, WPUV is applied in two perpendicular coats with Hi-Flex MS sealant used for terminations and joints. Tiled finish is installed over the cured membrane.
Best Practice Note
For balconies, always integrate waterstops and confirm bond with chosen tile adhesive system.
For Builders (Multi-Residential): Planter Box Waterproofing
The Engineering Challenge
Developer needs a low-VOC, UV-resistant membrane for planter boxes with water-retaining soil and exposure to sun.
The System-Based Solution with Everflex WPUV
Applied over primed screed and sealed penetrations, WPUV forms a flexible UV-rated barrier under drainage matting and soil.
Best Practice Note
Always include root barriers or slip coatings over membrane where plant growth is expected.
Performance Benchmark: WPUV vs Standard Acrylic Membranes
| Metric | Everflex WPUV | Standard Acrylic Membrane | Advantage |
|---|---|---|---|
| UV Resistance | Excellent ✔ | Moderate | Longer lasting exposed performance |
| Elongation | >300% ✔ | Approx. 120–180% | More movement capability |
| Dry Film Thickness | 1.0–1.3mm | 0.6–0.9mm | Improved durability |
| Recoat Time | 2–4 hours | 4–8 hours | Faster project turnaround |
Frequently Asked Questions
Is Everflex WPUV suitable for exposed roofs?
Yes — WPUV is UV stable and designed for fully exposed external use on rooftops, balconies, podiums, and other horizontal surfaces subject to sun, rain, and ponding water.
Can it be used under tiles?
Yes. WPUV can be used as a membrane under tiled systems in external areas. It must be fully cured and protected with suitable adhesive or topping layers. Compatible with most water-based tile adhesives.
Does it require a primer?
In most cases, no primer is required on clean, sound concrete, masonry, or FC sheet. For highly porous or dusty surfaces, a diluted first coat (as a primer) or bonding primer may be recommended.
Is it resistant to ponding water?
Yes. Everflex WPUV is designed to resist ponded water on horizontal surfaces once fully cured. Minimum fall is always recommended for drainage, but the membrane will not degrade from standing water.
What is the recoat time and full cure time?
At 23°C and 50% RH, recoat time is approx. 2–4 hours, and full cure occurs after 5–7 days depending on film thickness and weather conditions.
Applications & Benefits
| Application / Use Case | Key Benefit | Primary Trades |
|---|---|---|
| Exposed concrete rooftops and podium slabs | UV-stable, Class 3 flexibility, and ponding water resistance | Waterproofers, Builders, Roofing Contractors |
| Balconies and verandas with trafficable toppings | Tough elastomeric film compatible with screed and tile beds | Tilers, Membrane Applicators |
| Planter boxes and podium garden beds (with drainage) | Resists microbial growth, root moisture, and standing water | Landscapers, Waterproofers |
| Retaining walls (protected) | Low VOC and non-flammable – safe for below-ground installations with board protection | Structural Contractors, Landscapers |
| FC sheet façades and blockwork walls | Forms a paintable barrier against weather and surface moisture ingress | Facade Applicators, Builders |
How to Apply Everflex WPUV
-
1. Prepare the Surface
All surfaces must be clean, dry, and structurally sound. Remove dust, oil, laitance, curing agents, and other contaminants. Light grinding or acid etching may be required on smooth concrete. -
2. Prime (if required)
On porous or absorbent substrates, use a diluted first coat of WPUV (1 part WPUV : 1 part water) as a primer. Allow to dry before applying full-strength membrane. -
3. Apply First Coat
Apply the first full coat using a roller, brush, or airless spray. Aim for an even, continuous film without pinholes. Allow to dry for 2–4 hours (at 23°C) before recoating. -
4. Apply Second Coat
Apply the second coat perpendicular to the first to ensure complete coverage and build-up of membrane thickness. Total dry film thickness should reach 1.0–1.5mm depending on exposure and specification. -
5. Cure and Protect
Allow membrane to cure for 5–7 days before permanent water exposure. Protect from foot traffic, rain, or UV topcoats during initial cure. Always refer to project-specific specifications for protection layers (tiles, screed, etc.).
Limitations & Safety
Product Limitations
- Do not apply to wet or saturated surfaces – substrate must be visibly dry and stable
- Not suitable for negative pressure waterproofing (e.g. rising damp, below-grade hydrostatic pressure)
- Not recommended for direct use over metal or plastic surfaces
- Must be topcoated if exposed to prolonged UV – though UV stable, protective coating enhances longevity
- Not trafficable without additional topping system – not designed as a wear surface
Safe Handling & PPE
- Wear gloves and eye protection during application
- Ensure adequate ventilation in enclosed areas
- Avoid contact with eyes or prolonged skin exposure
- Store sealed containers below 30°C; protect from freezing
- Refer to SDS for full safety, first aid, and disposal instructions
Adhesion & Surface Compatibility
✅ Excellent Adhesion – No Primer Required
- Concrete (cured, clean, and sound)
- Masonry block and render
- Fibre cement sheet (FC sheet)
- Cement screed or topping slabs
- Compressed sheet sheathing
Everflex WPUV adheres directly to most clean, dry porous substrates without priming. Surfaces must be structurally sound, free from laitance, dust, oil, or release agents.
⚠️ Surface Testing Recommended
- FC sheet with pre-sealers or coatings
- Old membranes or coatings (acrylic, bitumen)
- Painted or sealed concrete
- Timber sheathing (only if approved and sealed)
On non-porous or coated surfaces, adhesion should be confirmed by site testing or using a diluted first coat as a primer.
❌ Not Suitable
- Plastic and PVC surfaces
- Metal substrates (zinc, aluminium, steel)
- Wet or ponded substrates
- Bituminous membranes or tar-based systems
WPUV is not formulated for adhesion to metal, plastic, or oily substrates. Do not apply to surfaces with active leaks or standing water.
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