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For internal wet area flooring and tiling installations on challenging or cracked substrates, Gripset XpressLay PVC Membrane provides a high-strength, self-adhesive water and vapour barrier that acts as an anti-fracture underlay. It allows direct fixing of cement-based tile adhesives, membranes, and screeds without the need for torching, heat welding, or solvent-based primers.
How it works
XpressLay is a 1mm thick, reinforced PVC sheet backed with a high-tack adhesive. The sheet bonds directly to the floor substrate, isolating the finished tile bed from subfloor stress. Its high tensile strength (exceeding 2MPa) and Class II elongation allow it to absorb vibration, movement, and flexing in timber sheeting, structural plywood, and cracked concrete before these forces reach the tile layer. The self-adhesive backing makes it suitable for application in cold and humid environments where liquid membranes struggle to dry, establishing a reliable moisture barrier with a water vapour transmission rate of just 0.1g/24h/m².
Numbers that matter
- >2MPa tensile strength (AS 4654.1 Appendix A): High mechanical resistance to physical rupture, tearing, and subfloor movement.
- >60% elongation (AS1145.3): Class II elasticity to bridge non-structural subfloor cracks and resist vibration without tearing.
- 0.1g/24h/m² water vapour transmission (ASTM E96): Restricts vapour transmission, protecting timber underlays and sensitive floor finishes from rising moisture.
- 1.5% water absorption (AS 3558.1): Low water absorption performance to maintain structural integrity under persistent wet area conditions.
- -30°C to 80°C service temperature: Maintains structural stability and performance across extreme temperature shifts.
Where to use it
XpressLay is suitable for commercial, industrial, and residential applications on the following substrates:
- Concrete and screeds.
- Compressed fibre cement sheeting.
- Timber sheeting and structural plywood (functioning as a tile underlay alternative).
- Glazed surfaces, marble, granite, and ceramics (for tiling over existing tiles).
- Soft and rigid plastics, PVC, and DPC films.
- Over existing epoxy coatings, vinyl, or aged industrial floor coatings.
Limitations
- Suitable for floor and horizontal surfaces only. Do not use on vertical surfaces to support tiles or other finishes.
- Suitable for internal applications only. Do not use externally.
- Do not apply when surface or ambient temperatures are below 5°C or above 30°C.
- Not to be used as an exposed membrane finish; it must be finished over.
- Not to be used as a trafficable surface.
- Do not apply directly over expansion joints.
- Not compatible with solvent-based finishes applied over the membrane.
- Concrete substrates must be cured for at least 28 days; cement render and sand-cement screeds must cure for at least 7 days.
Installation and priming
All substrates must be clean, sound, smooth, dry, and free from contaminants. Gripset XpressLay must be applied onto primed surfaces. Priming is generally not required for non-porous, non-mineral surfaces like plastics and glazed surfaces when they are prepared, sound, and clean.
- Porous substrates: Prime with RLA Universal Primer diluted 1 part primer to 2 parts water. Apply one coat at a coverage rate of 1 litre per 5–10m².
- Non-porous substrates (mineral-based): Prime with undiluted RLA Universal Primer. Apply one coat at 1 litre per 5–10m².
- Green or damp surfaces: Apply 1 to 2 coats of Gripset E60 by brush or roller at a minimum coverage of 1 litre per 3m² per coat.
Detailing, joins, and tiling
To establish a continuous waterproofing or anti-fracture layer, follow these application requirements:
- Overlaps: All horizontal and vertical sheet joins must have a minimum 50mm overlap, pressed firmly with a hand-held vinyl roller. For waterproofing applications, coat all overlaps with a 100mm wide coat of a suitable Gripset liquid under-tile membrane applied centrally across the joint. No liquid coating is required on overlaps when used solely as an anti-fracture system in dry areas.
- Wall/floor junctions: Detail critical corner intersections after sheet installation using either Elastoproof B50 Joint Band embedded in a suitable Gripset liquid under-tile membrane, or self-adhesive BRW PF Tape sealed with a liberal coat of the liquid membrane.
- Penetrations and floor wastes: Slide the cut sheet over pipes and seal with Gripset liquid membrane, or use Elastoproof Collars or BRW PF Tape. For floor wastes, seal the interface between the sheet and the waste flange using BRW PF Squares before making the final centre cut.
- Tiling: Direct tiling over XpressLay requires polymer-modified cement-based adhesives, such as Gripset C-LITE, C-MASTIC, or C-RUBBER. For other adhesives, contact RLA Polymers to verify compatibility.
- Screeds and toppings: If applying a screed, render, or concrete topping over XpressLay, incorporate Gripset 11Y as a proprietary bonding agent and water-resistant additive in the mix, or use Gripset C-BED engineered screed.
Frequently asked questions
Can I tile directly over Gripset XpressLay?
Yes, Gripset XpressLay is compatible with polymer-modified cement adhesives such as C-LITE, C-MASTIC, and C-RUBBER. Ensure the sheet has full adhesion and the surface is clean before tiling.
Is XpressLay suitable for external or vertical surfaces?
No, Gripset XpressLay is designed strictly for internal horizontal surfaces. Do not use it outdoors or on vertical substrates, as its performance is not rated for these conditions.
Do I need to prime the surface before installation?
Yes, priming is required for most substrates to ensure proper adhesion. Use RLA Universal Primer for porous or non-porous surfaces, or Gripset E60 for damp concrete with high relative humidity or moisture content.
How should sheet overlaps be treated in wet areas?
All overlaps must be a minimum of 50mm and sealed with a 100mm wide coat of Gripset liquid membrane. This ensures watertightness and long-term durability in waterproofing applications.
Can XpressLay be applied over existing floor finishes?
Yes, XpressLay adheres well to properly prepared glazed, ceramic, vinyl, and epoxy floor finishes. Ensure these surfaces are clean, sound, and dry before application for optimal bond.
Applications and benefits
| Application | Key benefit | Primary trades |
|---|---|---|
| Internal wet area floors | Provides AS 4858 compliant waterproofing without cure time. | Tilers, Waterproofers |
| Anti-fracture underlay | Bridges minor substrate cracks, reducing tile damage from movement due to Class II elongation. | Tilers, Builders |
| Mixed substrate transitions | Offers uniform bond and waterproofing over differing subfloor materials. | Waterproofers, Specifiers |
| Overlaying existing floor finishes | Achieves high tack adhesion over glazed, ceramic, vinyl, or epoxy floors, speeding up renovation. | Remedial Contractors, Tilers |
| Fast renovation projects | Eliminates membrane cure times, allowing same-day tiling or screeding. | Waterproofers, Renovation Builders |
| Hybrid waterproofing systems | Forms a compatible base layer for detailing with Gripset liquid membranes. | Waterproofers |
Applying Gripset XpressLay: Step-by-Step
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1. Surface Preparation
Ensure the substrate is structurally sound, clean, dry (unless using E60), and free from contaminants. Vacuum dust, remove laitance, and prime appropriately.
- Porous Substrates: Prime with diluted RLA Universal Primer (2:1 water)
- Dense / Non-Porous: Use undiluted RLA Universal Primer
- Damp/Green Concrete: Prime with Gripset E60
Pro Tip: Avoid priming on hot days or direct sunlight—this can cause flash-drying and reduce adhesion. -
2. Sheet Positioning
Pre-cut sheets to fit the layout. Always ensure a 50mm overlap at sheet joints. Align rolls prior to removing the release film.
Pro Tip: Mark layout lines on the substrate using chalk or laser for precise alignment before peeling the film. -
3. Membrane Application
Peel back the release liner and gradually press the membrane onto the surface. Use a rubber roller or weighted vinyl roller to eliminate bubbles and enhance bond.
Pro Tip: Start from the centre and roll outwards. Apply consistent downward pressure across the entire sheet. -
4. Overlap Detailing
All sheet overlaps must be a minimum of 50mm. In waterproofing applications, apply Gripset liquid membrane over the joints at 100mm width for watertight protection.
Pro Tip: Use a roller on wet membrane over laps to fully bed the coating into the overlap join. -
5. Tiling or Screeding
Install tiles using polymer-modified cement adhesives (e.g. Gripset C-LITE, C-RUBBER). For screeds, ensure proper adhesion to the sheet and apply suitable bonding agents.
Pro Tip: Tiling can commence immediately after membrane install—no drying time required.
Product limitations
- Not for: Vertical or external surfaces. XpressLay is designed for internal horizontal floor use only.
- Not for: Areas with active negative hydrostatic pressure or rising damp. Ensure moisture is within allowable limits or use Gripset E60 primer as specified.
- Note: All sheet overlaps in wet area applications must be sealed with Gripset liquid membrane to ensure waterproofing compliance.
- Incompatible with: Solvent-based adhesives, primers, or topcoats. Use solvent-free systems only.
Safety and handling
Personal protective equipment
Wear gloves when handling the membrane or primers. Safety goggles and long sleeves are recommended when using associated primers.
Ventilation
Use in well-ventilated areas. While the sheet is inert, some primers may emit mild vapours; ensure good ventilation during primer application in confined spaces.
First aid
Refer to the Safety Data Sheet (SDS) of the specific primer used for complete first aid instructions, as Gripset XpressLay itself is inert.
- Eyes (for primers): Rinse with clean water for at least 15 minutes. Seek medical attention if irritation persists.
- Skin (for primers): Wash off with soap and water. Remove contaminated clothing.
- Inhaled (for primers): Move to fresh air. Consult medical advice if symptoms occur.
- Swallowed (for primers): Rinse mouth. Do not induce vomiting. Seek medical help immediately.
Storage and disposal
Store Gripset XpressLay flat in a dry area, out of direct sunlight. Do not expose to flame or extreme heat. Incorrect storage can deform roll edges. Shelf life is 12 months from the date of manufacture.
Substrate guide
Proper surface preparation and correct priming are critical for Gripset XpressLay to achieve its documented performance in internal wet areas and as an anti-fracture membrane.
Concrete and screed
Surface prep: Concrete must be cured for 28 days, screed for 7 days. Remove dust, laitance, and debris. Fill voids with Gripset 11Y or RLA levelling compounds.
Primer: Required. Use RLA Universal Primer diluted for porous concrete. For damp concrete with >80% RH or 5% MC, apply Gripset E60.
Fibrous cement sheeting
Surface prep: Ensure sheeting is securely fastened and free from contamination. Remove dust and fill joints if required.
Primer: Required. Apply undiluted RLA Universal Primer for bond and vapour resistance.
Timber and plywood
Surface prep: Securely fix sheeting with appropriate joist spacing. Substrate must be dry and clean. Sand away any coatings or wax.
Primer: Required. Use undiluted RLA Universal Primer for non-porous timber or diluted for raw sheeting.
Glazed tiles and epoxy finishes
Surface prep: Mechanically abrade smooth finishes. Clean thoroughly with an alkaline degreaser. Ensure surface is dry and structurally stable.
Primer: Required. Apply undiluted RLA Universal Primer. Gripset OP Primer can enhance bonding if needed.
Gripset XpressLay PVC Membrane Physical Properties
| Property | Value |
|---|---|
| Material Type | Solvent-free modified synthetic adhesive |
| Material Construction | Fleece-backed, non-woven synthetic |
| Elongation | Class II (≥200%) |
| Tiling Ready | Immediate – no curing time needed |
| Service Temperature | -10°C to 60°C |
| UV Resistance | Not UV stable – for internal use only |
| Bed Thickness | 1.0 mm |
| Minimum Overlap | 50 mm |
| Compatible Adhesives | Polymer-modified cement adhesives (e.g. Gripset C-LITE, C-MASTIC, C-RUBBER) |
| Primer Guidance | Priming required for most substrates |
| VOC Content | Zero (sheet is inert) |
| Certifications | AS 4858 (Internal Wet Area Waterproofing) |
| Shelf Life | 12 months from date of manufacture |
| Storage Conditions | Store flat in dry area, out of sunlight |