Dr. Fixit Powder Waterproof (IWC)
Chloride-free integral powder waterproofing compound that densifies concrete and plaster from within — a single 500 g dose per 50 kg bag of cement, tested to IS 2645:2003.
What is it?
An integral powder waterproofing admixture from Pidilite — waterproofing additives dispersed in an inert fine filler — gauged into concrete and cement plaster at the mixing stage to cut water permeability.
Where is it used?
Basements, roof slabs and screeds, water-retaining structures, bathrooms and balconies — anywhere a mortar or concrete mix must resist dampness at source.
Why use it?
Brings water permeability down to under 50 percent of the control mix at a nominal dosage, without penalising setting time or compressive strength, and with zero chloride to endanger reinforcement.
How is it applied?
Blend 500 g into the dry cement-sand mix for every 50 kg bag of cement before gauging water goes in, then place, compact and water-cure exactly as you would a normal mix.
About Dr. Fixit Powder Waterproof (IWC)
Dr. Fixit Powder Waterproof — listed on our site as Dr. Fixit IWC — is Pidilite’s integral powder waterproofing compound for plaster and concrete. Rather than sitting on the surface the way a coating does, it goes into the mix itself: a measured 500 g charge per 50 kg bag of cement, folded into the dry cement-sand blend before water is added. Once the mix hydrates, the treated matrix is noticeably more cohesive and dense, and laboratory testing to IS 2645 shows water permeability falling below half that of an untreated control mix.
For site teams, the powder format is the practical advantage. There is no liquid to decant, no dispenser to calibrate, and no risk of dosage drift when labour changes between shifts — one pouch per bag is an instruction a mason can follow without supervision. It is compatible with every type and grade of cement used in Indian construction, and because the formulation is chloride-free it can be specified in reinforced work without any corrosion concern. Space Arc Engineering supplies genuine Pidilite stock across Delhi NCR and pan-India, with application guidance for contractors and consultants.
The technical insight
Water travels through concrete and plaster along capillary pores and micro-voids left behind as excess mixing water evaporates. An integral waterproofer attacks that pathway from inside the mix. The active additives in Dr. Fixit Powder Waterproof are carried on an inert fine filler that distributes them uniformly through the cement paste during dry blending. As hydration proceeds, the treated paste packs tighter — the mix becomes more cohesive, bleed channels are reduced, and the capillary network that would otherwise wick moisture is refined and interrupted. The result registers directly in the IS 2645 permeability test, where treated specimens pass less than 50 percent of the water an identical control mix does, while setting behaviour and 28-day compressive strength remain in line with the untreated mix. In other words, you gain water-tightness without trading away structural performance.
Where it is used
- Basement retaining walls, rafts and associated mortar work
- Roof slabs and waterproof screeds on terraces
- Water-retaining structures such as overhead and underground tanks and sumps
- Bathroom and toilet plaster, bedding and sunken-portion filling
- Balconies, chajjas and other rain-exposed projections
- External cement plaster on facades and parapets
- General concrete and masonry mortar where a dense, low-permeability mix is specified
Key advantages
- Water permeability reduced to below 50 percent of the control mix when tested per IS 2645
- Chloride-free formulation — no risk of reinforcement corrosion, safe for all RCC work
- Compressive strength matches the control mix, so no structural derating is needed
- Setting time stays within IS 2645:1983 test limits at 30 degrees C
- Compatible with all types and grades of cement, including OPC and blended cements
- Among the most economical waterproofing measures per bag of cement — one 500 g dose treats a full 50 kg bag
- Free-flowing powder is simple to batch on site: no liquid dispensing, spillage or dosing-pump calibration
Limitations & considerations
- Must be blended into the dry cement-sand mix only — it cannot be added to gauging water or to already-wet concrete or mortar
- It is an integral admixture, not a membrane: it will not bridge structural cracks, cold joints or moving substrates
- Performance depends on overall mix discipline — a high water-cement ratio, poor compaction or skipped curing will undermine the benefit
- Dosage must be measured per 50 kg bag; casual over- or under-dosing defeats the tested performance basis
- Shelf life is 12 months in unopened packs stored cool and dry, away from sun, heat and fire
Selection & best practice
Batch it dry, always. For hand mixing, spread the cement and sand, add 500 g of powder per 50 kg bag of cement, and turn the heap with a spade until the colour is uniform before any water is introduced. For machine mixing, charge cement and sand into the mixer, run it for one minute, add the measured powder, mix a further minute, then add potable water strictly to the designed water-cement ratio and mix two to three minutes to a lump-free, homogeneous mass. Place into shuttering or apply as plaster promptly, compact well, and water-cure as per normal practice — curing is what lets the densified matrix develop. Never tip the powder into water or into a wet mix; it must coat the dry ingredients first. Wear rubber gloves and safety goggles while handling, and rinse skin with plenty of water on contact.
Specifications
| Appearance | Free-flowing powder |
| Colour | Off white |
| Bulk density (tapped) | 0.5 to 0.8 g/ml |
| Dosage | 500 g per 50 kg bag of cement |
| Standard compliance | Meets requirements of IS 2645:2003 |
| Setting time at 30 deg C (IS 2645:1983) | Passes |
| Compressive strength (IS 2645:1983) | Matches control mix |
| Water permeability (IS 2645:1983) | Less than 50% of control mix |
| Shelf life | 12 months in unopened packs, stored cool and dry |
Industry use cases
Residential construction
Builders and individual home-owners dose bathroom plaster, terrace screeds and external rendering to stop dampness and paint failure before they start — one pouch per cement bag keeps site batching foolproof.
Commercial and institutional buildings
Basement walls, sunken slabs in toilets and balcony projections in office, hospital and school projects gain a dense, low-permeability mix that backs up the primary membrane system.
Water infrastructure
Overhead tanks, underground sumps and other water-retaining structures use the admixture through walls and base mortar to limit seepage through the concrete body itself.
Repair and renovation contractors
Replastering of damp-affected walls and re-screeding of leaking terraces perform far better when the fresh mortar itself is waterproofed rather than relying on the old substrate.
Mass housing and boundary works
Compound walls, parapets and plinth masonry across large housing sites get economical, repeatable protection without specialised applicator crews.
Frequently asked questions
What is the correct dosage of Dr. Fixit Powder Waterproof?
Can I add it to concrete or mortar that is already mixed with water?
Will it reduce the strength of my concrete or delay setting?
Is it safe for reinforced concrete?
How is it different from Dr. Fixit Pidiproof LW+?
Can it replace a terrace waterproofing membrane?
How we position Dr. Fixit Powder Waterproof (IWC)
Within the Dr. Fixit family, choose Powder Waterproof when you want dry-batch dosing, and Dr. Fixit Pidiproof LW+ when a liquid admixture in the gauging water suits your site better. For positive-side protection over the finished surface, pair the treated mix with Dr. Fixit Newcoat on terraces or Dr. Fixit Pidifin 2K in bathrooms and tanks. Space Arc also stocks equivalent integral systems from our other principals — Fosroc Conplast WP90 and Sika’s Plastocrete-range admixtures — so consultants can specify by brand standard while keeping one supply line. Talk to our technical desk for a mix-specific recommendation.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.