For internal wet areas and external above-ground structures requiring a compliant barrier under screeds, tiles, or pavers, Silcor 560 HB Charcoal Membrane provides a high-build, fully bonded waterproofing layer. This one-part polyurethane cures via atmospheric humidity to form a seamless, elastomeric barrier that prevents water tracking beneath the surface of concrete, screeds, and structural timber sheets.
Silcor 560 HB Charcoal Membrane is formulated to build high film thickness on both vertical and horizontal surfaces without sagging. The liquid-applied polyurethane cures into a monolithic membrane, eliminating the vulnerable joins and laps common to sheet systems. Because it bonds directly to primed substrates, it prevents water from tracking horizontally beneath the membrane in the event of a localized puncture. It contains no bitumen or tar, ensuring it will not bleed or stain overlying finishes.
This membrane is designed for use in non-exposed, fully covered applications over prepared and primed substrates including concrete (minimum 20 MPa), cementitious screeds, Compressed Fibre Cement (CFC) sheets, water-resistant plasterboard, and water-resistant structural timber. Typical locations include:
Successful installation requires systematic substrate preparation, priming, and specific detailing at joints:
No, SILCOR 560 HB is specifically for non-exposed applications. For areas under pods and pavers, it must be protected with SILCOR Top Coat 75 or another UV-blocking layer.
Concrete must be structurally sound, with a minimum compressive strength of 20 MPa and a pull-off strength of 0.6 MPa (internal) or 1.0 MPa (external). It requires thorough cleaning and priming before application.
This Class III membrane offers high extensibility, certified at over 700% elongation, and passes cyclic movement resistance tests, accommodating typical structural movements in construction. For expansion joints with over 15mm movement, consult a GCP representative.
No, SILCOR 560 HB is not recommended for the internal lining of water tanks. Its formulation is designed for waterproofing under screeds, tiles, or other protective coverings.
Applying below 35% relative humidity will extend the cure time significantly, delaying subsequent trades. Ensure humidity is within the 35% to 85% range during application and cure.
| Application | Key benefit | Primary trades |
|---|---|---|
| External balconies, rooftops, and decks (under screed, pavers, or ballast) | Certified Class III compliance to AS 4654.1 ensures robust, non-exposed waterproofing. Seamless application eliminates vulnerable joins, reducing leak risks. | Waterproofers, Builders, Architects |
| Internal wet area floors (bathrooms, laundries, kitchens) | Meets AS/NZS 4858-2004 and AS 3740-2021 standards for internal waterproofing. High elongation (>1400% AS 4858) handles structural movement without cracking. | Waterproofers, Tilers, Builders |
| Planter boxes, green roofs, and landscaped decks | Forms a monolithic barrier under root protection or drainage layers. Fully bonded application prevents water tracking under the membrane. | Landscapers, Waterproofers, Builders |
| Retaining walls and lift pit walls | High build properties allow for efficient application on vertical surfaces, creating a continuous, flexible seal against moisture ingress. | Waterproofers, Civil Contractors |
| Under bonded screeds or direct-stick tiles (with required tie coat) | Provides a durable, flexible waterproofing layer that accepts subsequent bonded finishes when a SILCOR 575 HB tie coat and aggregate is applied. | Waterproofers, Tilers, Builders |
Professionals using Silcor 560 HB must prioritise safety and adhere to Australian Workplace Health and Safety (WHS) standards.
Danger
SILCOR 560 HB is a combustible liquid. It is harmful if inhaled and causes serious eye damage and skin irritation. May cause allergy or asthma symptoms or breathing difficulties if inhaled.
Wear protective gloves (rubber or nitrile rubber), safety glasses with side shield protection, and protective clothing. If exposure limits may be exceeded or in inadequate ventilation, use approved respiratory protective equipment appropriate for organic vapours.
Use only outdoors or in a well-ventilated area. Ensure good interior ventilation, especially at floor level, as fumes are heavier than air. Avoid breathing dust/fume/gas/mist/vapours/spray.
Store in original, tightly sealed packaging between 15°C and 25°C, under cover, protected from heat, ignition, moisture, frost, and direct sunlight. Shelf life is 9 months. 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 560 HB, ensuring full adhesion and preventing common failures.
Surface prep: Substrates must be at least 14-28 days old, depending on thickness and moisture, with a minimum compressive strength of 20 MPa. Clean surfaces of all dirt, dust, laitance, curing compounds, and contaminants using brooming, vacuuming, water blasting (4000 psi), or grinding. Repair defects like bug holes or honeycombing with a low-shrinkage repair mortar of equivalent strength. Chase construction joints minimum 10mm x 10mm. Ensure concrete pull-off strength is at least 0.6 MPa for internal wet areas and 1.0 MPa for external surfaces.
Primer: Required. For moisture content below 5.0%, use SILCOR Primer BS or EPOCOTE™ F100W Clear. For highly porous or old concrete, use EPOCOTE F100W Grey. For 5.0% to 6.9% moisture, use EPOCOTE F100W Clear only, or allow drying below 5.0%. Prime when substrate temperature is stable or falling to minimise outgassing. Apply SILCOR 560 HB within the primer's recoat window.
Surface prep: Ensure screeds are structurally sound, fit for purpose, and have a minimum compressive strength of 20 MPa. They must be cured for at least 3 days, providing a smooth surface free of voids or excessive porosity. Follow concrete preparation guidelines for cleaning and repairs.
Primer: Required. Selection is based on moisture content and porosity, similar to concrete. Use SILCOR Primer BS or EPOCOTE™ F100W Clear for moisture below 5.0%. EPOCOTE F100W Clear is required for 5.0% to 6.9% moisture.
Surface prep: Substrates must be installed to stable, structural framing and finished according to the manufacturer’s directions. Ensure they are free of all surface sealers, coatings, and primers before application.
Primer: Required. SILCOR Primer BS is recommended for maximum penetration and adhesion to CCS flooring substrates. EPOCOTE™ F100W Clear is also suitable.
Surface prep: Clean surfaces thoroughly, ensuring they are free of corrosion, gaps, holes, and defects. For difficult-to-bond metals like stainless steel, copper, or aluminium, prepare, clean, then wipe on Dow Chemical DOWSIL 1200 OS Primer as per manufacturer directions.
Primer: Required. Use EPOCOTE™ F100W Clear or SILCOR Primer BS. For difficult metals pre-treated with DOWSIL 1200 OS Primer, the membrane can be applied directly after primer treatment.
| Property | Value |
|---|---|
| Membrane Chemistry | High solids, moisture curing polyurethane |
| Appearance | Charcoal grey viscous liquid |
| Specific Gravity | 1.48 g/ml |
| Brookfield Viscosity | 60,000 mPa.s |
| Solids Content | 91 %w/w |
| VOC | <110 g/L |
| Min Recoat Time | 12 hours |
| Max Recoat Time | 48 hours |
| Rain Resistant Time | 2 hours |
| Min Through Cure Time | 48 hours |
| Shore A Hardness | > 55 °A |
| Tensile Strength | > 5.0 MPa (AS 4858), > 3.0 MPa (AS 4654.1) |
| Elongation | > 1400 % (AS 4858), > 700 % (AS 4654.1) |
| Classification | Class III High Extensibility (AS 4858 / AS 4654.1) |
| Resistance to Cyclic Movement | Pass – No fatigue cracking exhibited |
| Water Vapour Transmission Rate | 4.36 g/m²/24h |
| Resistance to Water Immersion | Pass |
| Resistance to Bleach Immersion | Pass |
| Resistance to Detergent Immersion | Pass |
| Resistance to Heat Ageing | Pass |
| Flashpoint | >72 °C |
| Density at 20 °C | 1.5 g/cm³ |
Here are some common examples on where Silcor 560 HB Charcoal Membrane used by our customers.
