Dr. Fixit Pidifin 2K
Two-part acrylic-modified cementitious coating that cures into a tough, flexible, seamless waterproof membrane — CFTRI certified for potable water tanks and tested against a 10 m hydrostatic head.
What is it?
A two-component polymer-modified cementitious waterproofing membrane from Pidilite — a liquid acrylic emulsion and a cement-based powder supplied as a pre-batched kit, mixed on site into a brushable slurry.
Where is it used?
Water tanks, bathrooms and toilets, kitchen wet areas, swimming pools, basement walls, lift pits, chhajjas, planters and internal damp walls across residential and commercial projects.
Why use it?
It bonds to damp concrete without a primer, stretches about 60% to ride over hairline cracks, resists water pressure up to a 10 m head, and is CFTRI certified for drinking-water contact.
How is it applied?
Blend the full liquid and powder parts mechanically, then brush-apply two coats at roughly 2 kg/m² total onto a saturated-surface-dry substrate. No water, sand or cement is added.
About Dr. Fixit Pidifin 2K
Dr. Fixit Pidifin 2K answers a problem every contractor in India knows well: site-mixed cement slurries that crack the moment the structure moves. Pidilite solves it by factory-batching an acrylic polymer liquid and a cementitious powder in a fixed 1:2 ratio, so the applicator simply combines the two parts and gets a consistent, flexible waterproofing slurry every time. Once cured, the coating behaves as a seamless membrane rather than a rigid mortar — it accommodates the minor shrinkage and thermal movement typical of Indian rooftops, sunken slabs and RCC tanks without opening up leak paths.
For Delhi NCR builders, its biggest practical advantage is tolerance of damp substrates. New concrete only needs to reach a saturated-surface-dry condition before coating, which keeps waterproofing off the critical path during monsoon-season construction. Space Arc Engineering stocks the full kit range from the 3 kg bathroom pack to the 90 kg project pack, and our applicator teams handle everything from a single overhead tank to basement-wide treatments Pan-India.
The technical insight
The performance comes from co-curing two binder systems. As the cement in the powder component hydrates, the acrylic polymer (over 18% content in the mix) coalesces around the forming crystal matrix, threading elastic polymer film through what would otherwise be a brittle cementitious layer. The result is a membrane with 2.5 N/mm² tensile strength and 60% elongation — enough to bridge cracks up to 1 mm wide (ASTM C 836) at just 0.7–1 mm total film thickness. Because the binder is cement-compatible, adhesion develops chemically as well as mechanically, reaching 1.75 N/mm² on concrete at 7 days (ASTM D 4541) with no primer, and holding 1.0 N/mm² even after water immersion. Water absorption stays below 6%, which is why the cured film shows no leakage under a 10 m hydrostatic column.
Where it is used
- Overhead and underground water storage tanks, including CFTRI-certified potable water tanks
- Bathrooms, toilets and kitchen sink surrounds before tile fixing
- Swimming pools, spas and water reservoirs
- Basement walls, concrete foundations and lift pits
- Chhajjas, concealed roofs, balconies and planter boxes
- Podium and parking decks where the coating is protected by a screed
- Internal damp walls and moisture-affected masonry surfaces
Key advantages
- Pre-batched 1:2 kit removes site dosing errors — nothing to weigh, no water to add
- Applies directly on damp (saturated-surface-dry) concrete, saving programme time
- 60% elongation with 1 mm crack-bridging absorbs normal structural movement
- No leakage up to 10 m hydrostatic pressure — dependable for tanks and sumps
- CFTRI certified safe for drinking-water tank interiors
- Primerless adhesion of 1.75 N/mm² to concrete at 7 days, retained under immersion
- VOC-free and low odour, suitable for occupied buildings and interior wet areas
- Accepts tiling over the cured film with polymer-modified adhesives in bathrooms
Limitations & considerations
- Not suitable for direct foot or vehicular traffic — protect with a screed where decks are used
- Crack-bridging is limited to about 1 mm; live or structural cracks need separate treatment before coating
- Brush application of the neat slurry only — never dilute with water or extend with sand or cement
- Tanks and pools must cure at least 7 days before filling, which must be built into the schedule
- Intended for concealed situations; fully exposed, UV-hit terraces are better served by an exposed-grade membrane
- Working time is short once mixed (set-to-touch about 45 minutes), so batch only what the crew can place
Selection & best practice
Preparation decides the outcome. Let new concrete cure fully, remove oil, grease, laitance and loose material, and repair spalled areas until the substrate is sound. Pre-wet to a saturated-surface-dry state — damp, with no standing water. Mix by slowly adding the entire powder part into the entire liquid part under a mechanical stirrer until the slurry is lump-free, then let it stand 5–10 minutes so entrapped air escapes. Brush on the first coat at about 1 kg/m², work it well into corners and around pipe penetrations, and recoat after the first coat has dried — at 25°C plan on several hours; hot Delhi summers shorten this, winters extend it. Target 2 kg/m² total in a minimum of two coats for a 0.7–1 mm dry film. Allow 12–24 hours of curing after the final coat before follow-on trades, and a full 7 days before ponding tests or filling tanks and pools. Wash tools with water immediately; cured material only comes off mechanically.
Specifications
| Mixing ratio (liquid : powder) | 1 : 2 by weight, factory pre-batched |
| Coverage | Approx. 2 kg/m² total in minimum 2 coats (about 7 m² per 15 kg kit) |
| Recommended dry film thickness | 0.7 – 1.0 mm total |
| Tensile strength (ASTM D 412) | 2.5 N/mm² |
| Elongation at break (ASTM D 412) | 60% |
| Adhesion to concrete at 7 days (ASTM D 4541) | 1.75 N/mm² (1.0 N/mm² after water immersion) |
| Crack bridging (ASTM C 836) | Up to 1 mm |
| Pack sizes | 3 kg, 15 kg, 30 kg and 90 kg two-part kits |
| Shelf life | 12 months in sealed containers at room temperature |
Industry use cases
Residential Housing
Waterproofing bathrooms, sunken slabs and overhead tanks in apartments and independent homes, with tiles fixed directly over the cured coating.
Hospitality & Clubs
Swimming pools, spas and water features where a flexible, seamless membrane must hold a permanent water column without leaching.
High-Rise Developers
Basement retaining walls, lift pits and planter boxes on podiums — areas where damp substrates and tight programmes rule out moisture-sensitive systems.
Institutions & Healthcare
CFTRI-certified protection for drinking-water tanks in schools, hospitals and hostels, plus low-odour treatment of interior wet areas in occupied buildings.
Water Infrastructure
Reservoirs, sumps and treatment-plant structures needing verified resistance to sustained hydrostatic pressure up to 10 m head.
Frequently asked questions
Is Pidifin 2K safe for drinking-water tanks?
How much area does a 15 kg kit cover?
Can it be applied on a damp surface?
Can tiles be laid directly over the coating?
Do I add water, cement or sand to the mix?
When can I fill the tank or pool after coating?
How we position Dr. Fixit Pidifin 2K
Pidifin 2K is Dr. Fixit’s workhorse flexible slurry for tanks, wet areas and concealed structures — the right pick when you need certified potable-water safety and damp-surface application at a sensible cost. Where the demands change, we recommend accordingly: Dr. Fixit Newcoat for exposed, UV-hit terraces; Dr. Fixit Fastflex where higher movement capacity is expected; Dr. Fixit Krystalline for negative-side basement pressure; and Dr. Fixit Pidiproof LW+ as an integral admixture at the concreting stage. Space Arc also stocks comparable acrylic-cementitious systems — Fosroc Brushbond and Sika’s SikaTop Seal-107 — so specifiers can match brand standards already written into their projects. Talk to our team for a system recommendation and applicator support across Delhi NCR and Pan-India.
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