Sikasil Pool Silicone Sealant

For joints in and around swimming pools, areas under permanent water immersion, and frequently wet areas between tiles, concrete, glass, and metals, Sikasil Pool is the neutral-curing silicone sealant that resists chlorinated water and fungal growth while maintaining its bond under permanent immersion.

Water and chlorine resistance

Sikasil Pool is formulated for constant water exposure. Unlike standard sanitary silicones, its chemical structure is designed to withstand the continuous presence of pool chemicals and high chlorine concentrations without degrading. The neutral-cure chemistry is non-corrosive, making it safe for use on sensitive metals such as stainless steel, galvanised steel, and anodised aluminium. It incorporates biocides to resist fungal attack in warm, damp environments, provided the pool chemistry is correctly maintained.

Numbers that matter

• ±25% movement capability (ISO 9047): Accommodates the expansion and contraction of concrete pool shells, tiles, and metal fittings under thermal shifts.
• 7-day minimum cure: The required curing window before filling the pool with water, varying based on temperature, humidity, and the thickness of the applied sealant.
• ~2.0 mm per 24 hours cure rate: Standard curing speed at 23 °C and 50% relative humidity, with a fast 5-minute skinning time for efficient finishing.
• 10 mm to 15 mm joint width: Sourced joint design parameters. Joint depth must be at least 6 mm, with a maximum joint width limit of 15 mm.
• ~1.5 N/mm² tensile strength (ISO 8339): High physical strength to withstand hydrostatic pressure and mechanical cleaning equipment under water.

Where to use it

Sikasil Pool forms a flexible joint between a wide range of pool and wet-area substrates, including glazed tiles, concrete, glass, aluminium, anodised aluminium, stainless steel, and galvanised steel. It is also suitable for copper, brass, titanium-zinc, PVC, aerated concrete, cement-based renders, mortars, and bricks when prepared with the recommended primers.

Limitations

• No paintability: Sikasil Pool cannot be overpainted.
• Joint dimensions: Do not use on joints with widths greater than 15 mm or depths/thicknesses less than 6 mm.
• Substrate exclusions: Do not use on bituminous substrates, natural rubber, EPDM rubber, or any building materials that may bleed oils, plasticisers, or solvents.
• Application limits: Do not use for structural glazing, insulated glazing, food contact applications, or medical and pharmaceutical uses.
• Natural stone: Contact Sika Technical Service for advice before using on natural stone.
• Colour changes: White silicone may yellow over time when exposed to pool chemicals, high temperatures, or UV radiation. This change is purely aesthetic and does not affect the technical performance or durability of the sealant.
• Chlorine and pH limits: Pool water must maintain a pH value between 6.5 and 7.6, and free chlorine must remain below 5 mg/l (5 ppm). To prevent fungal growth, free available chlorine must not drop below 0.3 mg/l in swimming pools or 0.7 mg/l in warm water whirlpools.
• Detergent warning: Do not use acid-based detergents, as they increase the risk of fungal attack.

Substrate preparation and priming

Substrates must be clean, dry, sound, and free of oils, grease, dust, and loose particles. For joints subject to permanent water immersion or high physical stress, use the following pre-treatment procedures:

• Aluminium, anodised aluminium, stainless steel, glass, galvanised steel, powder-coated metals, or glazed tiles: Clean and pre-treat with Sika Aktivator-205 using a clean towel. Allow a flash-off time of 15 minutes to 6 hours before sealing.
• Copper, brass, and titanium-zinc: Pre-treat with Sika Aktivator-205, allow flash-off, then apply Sika Primer-3 N with a brush. Allow a further 30 minutes to 8 hours flash-off time.
• PVC: Clean and pre-treat with Sika Primer-215 applied with a brush. Allow 30 minutes to 8 hours flash-off time.
• Concrete, aerated concrete, cement-based renders, mortars, and bricks: Prime with Sika Primer-3 N applied with a brush. Allow 30 minutes to 8 hours flash-off time.

Application instructions

Insert a closed-cell, polyethylene foam backing rod to the required depth. Extrude the sealant into the joint, ensuring full contact with the joint sides to avoid air entrapment. Firmly tool the sealant against the joint sides to establish adequate adhesion. If masking tape is used for neat joint lines, remove the tape within the 5-minute skinning time. Smooth the surface using Sika Tooling Agent N or another compatible, solvent-free tooling agent.

Clean tools and application equipment immediately after use with Sika Remover-208. Cured material can only be removed mechanically.