G4 Pond Sealer Clear – Waterproof Concrete Pond Sealant

G4 Pond Sealer Clear – Waterproof Concrete Pond Sealant (1kg, 2.5kg & 5kg)

G4 Pond Sealer Clear is a professional-grade, cold-curing polyurethane resin specifically developed for sealing and waterproofing concrete, rendered, brick, and porous stone ponds. Widely regarded as an industry standard, G4 pond sealer creates a tough, durable, and fully watertight finish, making it ideal for koi ponds, garden ponds, water features, and formal concrete pond constructions.

Once cured, G4 forms a hard, impermeable coating that permanently seals porous surfaces, preventing water loss while remaining safe for fish and aquatic life. Its low-viscosity formulation allows it to penetrate deep into concrete and masonry, significantly strengthening the substrate while providing long-term waterproof protection.

G4 Pond Sealer is commonly used as part of a multi-coat system. Standard practice is to apply two coats of clear G4, followed by an optional black G4 top coat for enhanced UV resistance and a uniform dark pond finish. Clear G4 is often chosen for the base coats due to its excellent penetration and cost-effectiveness.

Coverage is excellent, with 5kg sufficient for approximately 10m² when applied in three coats, depending on surface porosity. G4 cures at low temperatures, making it suitable for use in a wide range of installation conditions.

Available sizes:

• 1kg – ideal for small repairs or detailing

• 2.5kg – suitable for medium pond projects

• 5kg – perfect for full pond builds and larger installations

G4 Pond Sealer Clear is trusted by pond builders and landscapers for its proven performance, ease of application, and long service life.

Browse compatible products and complete your installation with confidence by exploring our
Pond Sealants & Adhesives Collection.

Key Features & Benefits

• Cold-curing polyurethane pond sealer

• Creates a tough, watertight finish on concrete and masonry

• Suitable for rendered ponds, brick ponds, and porous stone

• Fish-safe once cured

• Excellent penetration and long-term durability

• Ideal base coat for black G4 pond paint

• Available in 1kg, 2.5kg, and 5kg sizes