About Sika Noleek

Sika Noleek is Sika’s dry-powder integral waterproofing admixture for concrete and mortar. Unlike a coating that sits on the surface, it works inside the mix: the fine mineral powder fills the capillary pores and voids that would otherwise let water track through hardened concrete. The result is a denser, better-compacted matrix that resists seepage as a permanent property of the concrete itself. It is supplied as a white fine powder with a bulk density of around 0.6 g/cc, carries no added chloride, and conforms to IS 2645, the Indian standard for integral waterproofing compounds.

For engineers and contractors, the appeal is simple: waterproofing that is designed in at the batching plant or on the mixer, not applied as an afterthought. Because the protection is distributed through the full thickness of the pour, it cannot be punctured, abraded or peeled the way a membrane or surface coat can. Sika Noleek is compatible with all varieties of Portland cement, including slag cement, and works across structural concrete and plaster alike. It is packed in 1 kg and 25 kg units, letting a site draw the right quantity for anything from a small plaster batch to a full structural pour.

The technical insight

Water moves through hardened concrete mainly along its capillary pore network, the interconnected micro-channels left behind as the mix hydrates and bleed water migrates out. Sika Noleek attacks that pathway directly. The fine mineral powder disperses through the paste and physically occupies and blocks these pores, breaking the continuity of the capillary channels so water has no easy route to travel. At the same time it improves compaction, producing a denser matrix with fewer voids and lower overall permeability, which also helps reduce drying shrinkage and gives a better surface finish. Crucially, it contains no added chloride, so it densifies the concrete without introducing the ions that drive reinforcement corrosion, a real concern with some older waterproofing salts. Because the mechanism is physical pore-filling rather than a surface film, the waterproofing property belongs to the concrete for its service life rather than to a layer that can fail independently.

Where it is used

• Structural slabs where a watertight, dense pour is specified
• Beams and columns forming part of the water-retaining or below-grade structure
• Internal cement plaster on walls prone to dampness and seepage
• External plaster and rendering exposed to rain and driving water
• Repair and renovation mortar where the patch must match the water resistance of sound concrete
• Roof and terrace screeds laid to falls for drainage
• Basement walls and rafts needing integral protection against ground water
• Water tanks and sumps where the concrete itself must resist permeation

Key advantages

• Waterproofs the concrete body from within, so protection cannot be scratched, worn or peeled off
• Chloride-free formulation that densifies concrete without threatening embedded reinforcement
• Effective pore filler that measurably cuts water seepage through the hardened matrix
• Improves compaction, giving denser concrete with fewer voids
• Reduces drying shrinkage and delivers a better surface finish
• Compatible with all varieties of Portland cement, including slag cement
• Low rebound loss and easy handling as a dry powder added at the mixer
• Supplied in 1 kg and 25 kg packs, so batches from plaster to structural pours are covered

Limitations & considerations

• It is an integral admixture, not a membrane; structures under continuous hydrostatic head, movement joints and construction joints still need a dedicated membrane or joint-sealing system
• Being a very fine powder, it must be thoroughly and evenly dispersed during mixing or pockets of untreated concrete can remain
• Waterproofing depends on correct dosage, a sound water-cement ratio and good compaction and curing; it cannot rescue an over-watered or poorly placed mix
• It does not bridge cracks that form after casting, so crack control by design and reinforcement remains essential
• Shelf life is 12 months from production and only in undamaged, unopened, sealed packaging kept dry between +10 C and +40 C

Selection & best practice

Specifications

Industry use cases

How we position Sika Noleek

Sika Noleek is the powder route to integral waterproofing. Where a project prefers a liquid dosed at the mixer, Sika’s own SikaCim or Sika-1 waterproofing admixtures cover the same integral-densifying job in liquid form, and Sika Antisol is the matching curing compound recommended for pours treated with Noleek. For crack-bridging surface protection on the same structure, pair it with a Sika cementitious or acrylic waterproof coating rather than relying on the admixture alone. Across our other brands, comparable integral admixtures include Dr. Fixit Pidiproof LW+ and MC-Bauchemie’s integral waterproofing range, while for below-grade and terrace work the admixture is best specified together with a membrane system rather than in place of one.

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