For stadiums, car park decks, plant rooms, and balconies requiring certified water protection under heavy traffic, Silcor 580 Membrane provides a seamless, elastomeric barrier. This two-part polyurethane liquid cures chemically to form a monolithic, fully bonded sheet that prevents water tracking between the membrane and structural substrates like concrete, engineered screeds, and compressed fibre cement.
Silcor 580 Membrane cures via a polyurethane resin-hardener reaction to deliver Class III high extensibility, allowing it to bridge non-structural concrete shrinkage cracks and absorb structural movements. Because it cures chemically rather than relying on atmospheric moisture, it achieves a rapid through-cure even in low-humidity environments. The semi self-levelling liquid flows out to a smooth, uniform finish on horizontal substrates set to falls, eliminating the weak points, seams, and laps common in sheet membranes. Formulated without bitumen or tar, the chemistry will not bleed through finishes or stain adjacent substrates.
Silcor 580 Membrane is suitable for application on dry, cured, and primed substrates including concrete (minimum compressive strength ≥20 MPa), cementitious screeds or renders (≥20 MPa), engineered screeds (≥25 MPa), compressed fibre cement sheet (CFC), cement composite sheet (CCS), water-resistant plasterboard, water-resistant plywood, structural timber, and prepared metals, PVC, and ABS plastics.
Common structural configurations include:
All concrete substrates must be structurally sound with a minimum concrete age of 14 to 28 days. Smooth concrete must have a minimum surface pull-off strength of 0.6 MPa for internal wet areas, 1.0 MPa for external foot traffic, and 1.5 MPa for light vehicle traffic. Clean substrates by shot blasting, grinding, or water blasting (4000 psi) to remove all contaminants, laitance, and curing compounds.
Prepare joints and corners by installing a minimum 15mm x 15mm bond breaker fillet of Silcor LM PU Sealant for external applications, or 12mm x 12mm for internal wet areas. Allow the sealant to cure for 12 hours. For active joints and cracks, apply a flexible, single-sided adhesive bond breaker tape (minimum 90mm wide for expansion joints) before membrane application.
Mix the 1:1 by weight polyol and iso components using a high-torque, variable-speed drill (maximum 600 RPM) with a clean paddle for 3 to 5 minutes. Transfer to a second clean container and re-mix for 1 to 2 minutes to prevent uncured pockets. Apply using a notched trowel, notched squeegee, or pin rake. To ensure the correct specified DFT is achieved, verify wet film thickness (WFT) regularly during application using a wet film gauge (typically every 2 square metres).
Yes, SILCOR 580 must be protected by a compatible top coat. For heavy foot and light vehicle traffic areas, apply a SILCOR 580 wear coat with broadcast sand, then overcoat with SILCOR Top Coat 80. For foot traffic only, SILCOR Top Coat 75 is used.
SILCOR 580 requires dry substrates, meaning below 5.0% moisture content for standard primers like SILCOR Primer BS. For substrates with 5.0% to 6.9% moisture, only EPOCOTE F100W Clear can be used, or the substrate must be dried further.
SILCOR 580 is semi self-levelling and formulated for horizontal substrates set to falls. It will run on vertical or ramped surfaces, so it is not suitable for those applications.
No, SILCOR 580 is not recommended for internal lining of water tanks. Its self-levelling properties make it unsuitable for this specific application.
| Application | Key benefit | Primary trades |
|---|---|---|
| Car park decks, stadiums, heavy foot/vehicle traffic areas | Withstands heavy loads and abrasion (80 Shore A hardness, >7MPa tensile strength, >700% elongation) preventing membrane failure under sustained use when properly protected with a wear coat and top coat. | Waterproofers, Civil Contractors, Builders |
| Balconies, roof decks, podiums (exposed to foot traffic) | Provides certified external waterproofing (AS 4654.1-2012 Class III) that bridges non-structural cracks and accommodates structural movement, preventing water ingress and callbacks. Requires a UV stable top coat. | Waterproofers, Builders, Tilers |
| Internal wet areas (under or over screeds) | Achieves internal wet area compliance (AS/NZS 4858-2004 Class III) for floors, offering a fully bonded, seamless barrier against moisture migration in laundries, bathrooms, and plant rooms. | Waterproofers, Tilers, Plumbers |
| Green roofs and landscaped decks | Forms a resilient, seamless waterproof layer that resists root penetration (when combined with root barrier or SILCOR 780 HI-LP) and withstands continuous service temperatures from -40°C to +100°C. | Landscapers, Waterproofers, Builders |
| Plant room floors, laboratories, sports centres (impact resistant flooring) | Creates a tough, chemically resistant (Passes bleach/detergent immersion) and impact-resistant surface when overcoated, protecting concrete from spills and heavy equipment. | Waterproofers, Industrial Flooring Contractors |
Before applying the main membrane, treat all internal corners, penetrations, and joints.
Install a 15mm x 15mm bond breaker fillet using Silcor LM PU Sealant to all internal corners. Allow to cure min 12 hours.
Correct mixing is critical for cure. Do not mix by volume.
Mix the Polyol (grey) first. Then weigh out Polyol and Iso (clear) in a strict 1:1 ratio by weight. Mix combined components for 3-5 minutes with a low-speed mechanical mixer avoiding air entrapment.
Apply to primed surface within the primer recoat window.
Use a 5mm notched squeegee or pin rake to spread the mix. This typically yields a 1.5mm cured thickness. Allow to self-level.
Apply in two cross-directional coats using a 10-14mm nap non-shedding roller.
Danger: SILCOR 580 (Isocyanate component) is classified as hazardous. It is fatal if inhaled, causes skin irritation, serious eye irritation, and may cause allergy or asthma symptoms or breathing difficulties if inhaled. It may also cause an allergic skin reaction and respiratory irritation.
Wear approved respiratory protective equipment if exposure limits may be exceeded. Use protective gloves (rubber gloves recommended), safety glasses with side shield protection, and appropriate body protection. Do not allow contaminated work clothing out of the workplace.
Ensure adequate ventilation during use. Use only outdoors or in a well-ventilated area to minimise inhalation exposure.
Store in original, unopened packaging between 15-25°C, under cover and protected from heat, ignition, moisture, frost, and direct sunlight. Shelf life is 12 months. Store locked up in a well-ventilated place with containers tightly closed. Dispose of contents and containers according to local regulations; do not allow product to reach sewage systems.
Proper substrate preparation and priming are critical for the long-term performance of SILCOR 580, preventing common adhesion failures.
Surface prep: Remove all contaminants, laitance, curing compounds, and weak material by water blasting (4000 psi) or grinding. Repair defects with a low shrinkage PMC mortar. Ensure a minimum concrete age of 14-28 days and a pull-off strength of 1.0 MPa (foot traffic) or 1.5 MPa (vehicle traffic).
Primer: Required. Use SILCOR Primer BS or EPOCOTE F100W Clear for moisture content below 5.0%. For moisture between 5.0% and 6.9%, use EPOCOTE F100W Clear only. Prime when substrate temperature is stable or falling to minimise outgassing and pin-holing.
Surface prep: Ensure sheets are installed according to manufacturer directions, clean, dry, and free from surface sealers, coatings, or acrylic primers.
Primer: Required. For CCS, SILCOR Primer BS is recommended for maximum penetration and adhesion. For CFC, SILCOR Primer BS or EPOCOTE F100W Clear is suitable.
Surface prep: Remove all corrosion, oxides, dirt, and grease. Roughen the surface by abrasion or garnet blasting to SA 2.5. Solvent wipe with xylene or MEK and prime within 30 minutes.
Primer: Required. Use EPOCOTE F100W Clear or SILCOR Primer BS. For difficult metals like stainless steel or copper, a DOWSIL 1200 OS Primer may be required before direct membrane application.
Surface prep: Install and finish according to manufacturer directions. Ensure surfaces are clean, dry, and free of sealers or primers.
Primer: Required. Use SILCOR Primer BS or EPOCOTE F100W Clear.
| Property | Value |
|---|---|
| Membrane Chemistry | High solids, 2-part reaction curing polyurethane |
| Appearance | Grey flowing liquid |
| Mix Ratio By Weight | 100 : 100 w/w |
| Specific Gravity (Mixed Membrane) | 1.23 g/ml |
| Brookfield Viscosity (Mixed Membrane) | 6,500 mPa.s |
| Solids Content | 97 %w/w |
| VOC | <35 g/L |
| Working Time (23°C / 60% RH) | 25 minutes |
| Pot Life (23°C / 60% RH) | 30 minutes |
| Tack Free Time (23°C / 60% RH) | 4 hours |
| Gel Time (23°C / 60% RH) | 3 hours |
| Min Recoat Time (23°C / 60% RH) | 15 hours |
| Max Recoat Time (23°C / 60% RH) | 36 hours |
| Min Through Cure Time (23°C / 60% RH) | 15 hours |
| Rain Resistant Min Cure Time (23°C / 60% RH) | 15 hours |
| Ready For Flood Testing / Topping / Backfilling (23°C / 60% RH) | 15 hours |
| Shore A Hardness | 80 °A |
| Tensile Strength | >7.0 MPa (AS 4858) / >8.0 MPa (AS 4654.1) |
| Elongation | >500 % (AS 4858) / >700 % (AS 4654.1) |
| Classification | Class III High Extensibility – AS 4858-2004 / AS 4654.1-2012 |
| Resistance To Cyclic Movement | Pass – No fatigue cracking exhibited |
| Bond Strength To Primed Concrete | >7.7 N (AS 4654.1) |
| Water Vapour Transmission Rate | 7.99 g/m²/24h |
| Resistance To Water Immersion | Pass |
| Resistance To Bleach Immersion | Pass |
| Resistance To Detergent Immersion | Pass |
| Resistance To Heat Ageing | Pass |
| Service Temperature (Continuous) | -40°C to +100°C |
| Substrate Temperature Range | +5°C to +35°C |
| Ambient Temperature Range | +5°C to +35°C |
| Relative Humidity Range | 35% to 85% |
| Dew Point | Minimum 3°C below substrate temperature |
| Minimum DFT (Non-Traffic / Foot Traffic) | 1.5 mm |
| Minimum DFT (Heavy Foot Traffic / Light Vehicle Traffic) | 3.0 mm |
Here are some common examples on where Silcor 580 Membrane used by our customers.
