Underneath screeds or pavers, a waterproofing membrane incapable of accommodating structural movement is a critical failure point. SILCOR 560 HB is engineered with Class III high-extensibility to handle typical building movements. This prevents costly failures in concealed waterproofing for external decks, planter boxes, or internal wet areas.

Why this product exists

SILCOR 560 HB was developed as an economical, high-solids, liquid-applied polyurethane membrane. It provides certified Class III high-extensibility waterproofing, compliant with AS 4654.1-2012 for external and AS/NZS 4858-2004 for internal non-exposed applications. It is the workhorse for concealed waterproofing jobs where compliant movement accommodation and cost-effectiveness are key. Unlike products designed for exposed or trafficable areas, SILCOR 560 HB focuses on delivering robust, certified performance for areas that will be covered, ensuring long-term integrity without unnecessary features or cost.

The numbers that matter

• Class III High Extensibility (>700% elongation / >3MPa tensile strength): This exceeds the minimum requirements for both AS 4858 (internal) and AS 4654.1 (external). It means the membrane can stretch and recover significantly, accommodating the typical structural movements and minor substrate cracking found in buildings. This robust flexibility prevents membrane failure due to building settlement or thermal expansion and contraction.
• <110 g/L VOC (Volatile Organic Compounds): This low VOC content supports healthier indoor air quality during application, especially relevant for internal wet area waterproofing, without compromising performance.
• 91% w/w solids content: A high solids content ensures that a greater proportion of the applied product remains as cured membrane. This contributes to achieving specified dry film thicknesses with fewer coats and provides a durable, high-build finish.
• 12-hour minimum recoat time at 23°C: This specific recoat window allows for efficient scheduling on site. Applicators can apply multiple coats within a standard working day or across consecutive days, maintaining membrane integrity and adhesion between layers.

What it's like to use

SILCOR 560 HB is a one-part, charcoal grey liquid, making application straightforward without the need for mixing multiple components. It is typically applied by roller or brush in two or more cross-directional coats, creating a seamless, monolithic membrane. The product is not self-levelling, allowing it to be used on both horizontal and vertical surfaces. Always prime the substrate with an appropriate GCP primer such as Silcor Primer BS for dry substrates or Epocote F100W for damp or green concrete to ensure optimal adhesion and performance. Clean equipment immediately after use with xylene solvent, as cured product requires mechanical removal.

Where this product excels

• External above-ground areas under screeds and pavers: For waterproofing balconies, rooftops, and decks that will be covered by screeds, tiles, drainage cells, or ballast, SILCOR 560 HB provides a robust, fully bonded Class III membrane that handles structural movement.
• Planter boxes and retaining walls: This membrane offers reliable waterproofing for landscaped areas and structures where the membrane will be permanently protected from UV exposure by soil or other backfill.
• Internal wet area floors: In bathrooms, laundries, and kitchens, SILCOR 560 HB delivers certified Class III performance under or over screeds, accommodating typical building movement to prevent water ingress.

How it fits in a real system

SILCOR 560 HB functions as the primary waterproofing layer in a multi-component system. Before application, the substrate must be clean, dry, and primed with a GCP product. For dry substrates, Silcor Primer BS ensures adhesion and penetration. For damp or green concrete, Epocote F100W provides a suitable base. Detailing, including internal corners, penetrations, and non-moving cracks, requires bond breaker fillets using SILCOR LM PU Sealant before membrane application. Once cured, the membrane must be protected. For unbonded screeds, PROTECTOBOARD or builder’s plastic acts as a slip sheet. If a bonded screed or direct-stick tiles are to be applied, a tie coat must be installed using Silcor 575 HB membrane wet-broadcast with aggregate. For exposed turn-ups, a protective top coat like Silcor Top Coat 75 is required to prevent UV degradation. For backfilled areas like planter boxes, PROTECTOBOARD or RAPID-DRAIN protects the membrane during installation.

Choose this when

• You need certified Class III waterproofing: This membrane meets the high extensibility requirements of AS 4654.1 (external) and AS/NZS 4858 (internal), crucial for compliance in Australian construction.
• The application is non-exposed: For areas that will be covered by screeds, tiles, pavers, ballast, or backfill, this product provides optimal performance without the added cost of UV stability.
• Structural movement is a factor: With over 700% elongation, the membrane effectively bridges typical substrate cracks and accommodates building movement.
• You require a one-part, liquid-applied solution: Its simple roller or brush application makes for efficient and seamless installation across various surfaces.

Don't use this when

• Not for: Applications exposed to UV radiation or regular foot traffic. For exposed, non-trafficable areas, consider silcor-575 with Silcor Top Coat 75. For trafficable applications, silcor-580 is a better fit.
• Not for: Damp, wet, or contaminated substrates. All substrates must be dry and adequately prepared; an appropriate GCP primer is always required.
• Not for: Negative pressure waterproofing or internal water tank lining.
• Not for: Very low VOC requirements beyond <110 g/L. For stricter VOC regulations, consider silcor-560-hb-low-voc.

Related products

• Silcor 560 HB Low VOC