About Fosroc Conplast WP90 Powder

Fosroc Conplast WP90 Powder is an integral waterproofing powder additive for concrete and cement mortar. Supplied as a fine, white, ready-to-use powder, it is added directly into the mix to reduce the permeability of the hardened concrete or mortar. Unlike admixtures in the wider Conplast range that modify workability, WP90 Powder is a non-plasticising, pore-blocking additive — it works physically by filling the natural capillary pores within the cement matrix, lowering porosity and improving water-tightness through the full section rather than only at the surface. It is neither a plasticiser nor a superplasticiser, so it should not be confused with dispersant-type Conplast products. Conplast WP90 Powder conforms to IS:2645-2003, the Indian Standard for integral cement waterproofing compounds, and is BIS certified, with chloride content as per IS:2645-2003. For India’s construction environment — ready-mix concrete (RMC) plants, precast yards, hot-weather casting and infrastructure works where water ingress and reinforcement durability are persistent concerns — an IS-conforming integral compound provides a dependable first line of defence against permeability-related deterioration. Space Arc Engineering, an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India, supplies genuine Conplast WP90 Powder in 1 kg and 25 kg packs together with site guidance on correct dosing and batching.

The technical insight

Conplast WP90 Powder reduces permeability by a physical pore-blocking mechanism: the fine powder fills the natural capillary pores and voids that form within the cement matrix as concrete or mortar hydrates and cures, lowering the interconnected porosity that allows water to migrate through the section. Because it is integrally batched rather than surface-applied, the water-tightness benefit is distributed through the full thickness of the element. The correct dosage is 1 kg of Conplast WP90 Powder for every 50 kg bag of cement in normal concrete and sand/cement mortar mixes — a figure that must be followed precisely, since under-dosing leaves capillary porosity inadequately filled and compromises water-tightness. As a non-plasticising additive, WP90 Powder does not act as a water reducer or workability aid; where both reduced permeability and improved workability are required, it is used alongside an appropriate plasticising admixture rather than in place of one. Conforming to IS:2645-2003 with chloride content within the IS limit, it is suited to reinforced concrete where chloride control matters for long-term durability.

Where it is used

• Basement concrete and below-grade elements requiring reduced permeability
• Roof slabs and screeds where water-tightness is needed
• Water-retaining structures
• External plastering for improved resistance to water penetration
• Bathrooms and wet areas
• Balconies and other exposed wet zones

Key advantages

• Integral pore-filling action reduces permeability through the full section, not just the surface
• Conforms to IS:2645-2003 and is BIS certified for assured quality
• Chloride content as per IS:2645-2003, supporting reinforcement durability in RCC
• Fine white powder, ready for use and easily batched into concrete or cement mortar mixes
• Single, clear dosage of 1 kg per 50 kg cement bag simplifies site batching
• Non-plasticising additive that can be combined with admixtures where workability is also required
• Available in convenient 1 kg and 25 kg packs for both small jobs and bulk site use
• Supplied by an authorised Fosroc distributor and applicator with Pan-India coverage

Limitations & considerations

• Not a plasticiser or superplasticiser — it does not reduce water demand or improve workability
• Performance depends on accurate dosing; under-application at less than 1 kg per 50 kg cement compromises water-tightness
• An integral compound that improves the concrete itself — it is not a membrane and does not replace dedicated waterproofing systems where these are specified
• Effective only when uniformly dispersed through the mix; requires proper batching with the dry materials
• Specific gravity is not published as a fixed value by Fosroc as it varies; refer to the batch Material Test Certificate where a value is required
• Does not substitute for sound mix design, adequate cover and good workmanship in achieving durable, water-tight concrete

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Conplast WP90 Powder

Positioned as Fosroc’s IS:2645-2003-conforming integral waterproofing powder for concrete and mortar, Conplast WP90 Powder competes with integral cement waterproofing compounds such as Dr. Fixit Pidiproof LW+ (a liquid integral compound), Sika WT-200 P / Sika powder waterproofing additives, and BASF MasterLife / MasterPel ranges. Space Arc Engineering leads with genuine Fosroc supply as an authorised distributor and applicator, positioning WP90 Powder as a powder-form, pore-blocking option for buyers who want a non-plasticising integral compound with clear single-rate dosing (1 kg per 50 kg cement) and BIS certification, while naming credible alternative brands where buyers wish to compare integral waterproofing chemistries.

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