Dr. Fixit Aquashield PU
Single-component, moisture-curing polyurethane liquid membrane that cures into a seamless elastic rubber with over 500% elongation — made for terraces, podiums and decks that keep moving.
What is it?
A one-pack, cold-applied polyurethane liquid waterproofing membrane that reacts with atmospheric moisture to cure into a fully crosslinked, seamless PU rubber film.
Where is it used?
Flat terraces, roof decks, podiums, balconies, planter bases, water features and bridge decks — particularly slabs with live cracking or thermal movement.
Why use it?
Cured elongation above 500% lets the film bridge active cracks 2–3 mm wide, where acrylics and rigid cementitious coatings tear or debond.
How is it applied?
Applied cold in 2–3 coats at 0.4–0.6 mm dry film per coat, building a 1.0–1.5 mm system, with 6–8 hours between coats at 23°C and 50% RH.
About Dr. Fixit Aquashield PU
Dr. Fixit Aquashield PU is a single-component polyurethane liquid waterproofing membrane from Pidilite’s Dr. Fixit range. Straight from the pail — no mixing, no catalyst, no hot works — it is spread over a prepared slab and cures by drawing moisture from the air and substrate. What starts as a liquid film finishes as a continuous polyurethane rubber with no laps, no joints and no termination bars, which is exactly why liquid PU has displaced felt and APP membranes on complicated Indian terraces crowded with pipes, upstands and machine foundations.
Where it earns its premium over acrylic terrace coatings is movement. A cured elongation beyond 500% and a tensile strength above 2.0 MPa mean the membrane stretches and recovers over cracks that open and close daily with slab temperature. Space Arc Engineering supplies Aquashield PU across Delhi NCR and Pan-India, and our applicator teams handle the detailing — mesh reinforcement, DFT control and protective topcoats — that decides whether a PU system lasts one monsoon or fifteen.
The technical insight
The chemistry is a moisture-triggered polyaddition. The liquid carries isocyanate-terminated polyurethane prepolymer; once exposed, ambient humidity reacts with those free isocyanate groups, chain-extending and crosslinking the film into an elastomeric network — no second pack needed. Because curing consumes moisture from both the air and the slab surface, film build discipline matters: each coat must stay within 0.4–0.6 mm dry film so moisture reaches the full depth, which is why the system is built in 2–3 passes rather than one thick pour. The finished network behaves like engineering rubber — it stretches across a 2–3 mm live crack and pulls back as the crack closes, cycle after cycle. Its one chemical weakness is aromatic UV degradation: unprotected PU chalks under direct sun, so exposed installations need a UV-stable topcoat or protective screed.
Where it is used
- Flat concrete terraces and roof decks, new or recoat
- Podium slabs and balconies on residential and commercial towers
- Rooftop gardens and planter boxes, where the cured film’s root resistance matters
- Water features, fountain basins and ornamental pond linings
- Bridge decks and flyover deck waterproofing beneath wearing courses
- Renovation of cracked, previously coated terraces after surface repair
- Post-tensioned slabs showing tendon-related surface cracking
Key advantages
- Single-component — no mixing ratios to get wrong on site, less wastage on small pours
- Elongation above 500% with active crack-bridging of 2–3 mm
- Seamless, fully bonded film — no laps or joints for water to track under
- Cold-applied, so safe on occupied buildings; no torches or hot bitumen
- Root-resistant when cured, suiting planters and landscaped decks
- Recoatable in 6–8 hours at 23°C, keeping multi-coat programmes moving
- Tensile strength above 2.0 MPa in the cured film for a robust, repairable membrane
Limitations & considerations
- Chalks under direct UV — exposed areas need a UV-protective topcoat or a protective screed/tile finish
- Moisture-cure chemistry is climate-sensitive: cure slows in cold, dry conditions and recoat windows must be respected
- Per-coat film build is capped at 0.4–0.6 mm DFT; heavy single passes cure poorly and can blister
- Needs a sound, dry, primed substrate — it is not a negative-side or damp-surface system
- Costs more per square metre than acrylic or bitumen-modified options; overkill for crack-free, low-movement roofs
- Pack sizes, coverage per litre and standards compliance are not published on this page — confirm against the current Pidilite datasheet for your batch before ordering
Selection & best practice
Start with the slab, not the pail. Grind off laitance and old coatings, repair spalls, and rework cracks wider than the membrane’s bridging range before coating. The substrate must be dry and primed — moisture-cure PU tolerates humid air, not wet concrete. Pre-treat every crack, coving, drain mouth and pipe penetration with a stripe coat plus embedded mesh reinforcement; details fail before fields do. Then build the system in 2–3 full coats at 0.4–0.6 mm dry film each, applying coats perpendicular to one another and holding the 6–8 hour recoat interval at around 23°C — sooner risks solvent/CO2 entrapment, much later needs surface checks for intercoat adhesion. Target 1.0–1.5 mm total DFT and verify with wet-film gauge readings during application. Finish exposed areas with a UV-protective topcoat, then flood-test for 48 hours before handing over or tiling.
Specifications
| Product type | Single-component, moisture-curing polyurethane liquid membrane |
| Cured form | Fully crosslinked, seamless polyurethane rubber film |
| Elongation at break | >500% |
| Tensile strength (cured film) | >2.0 MPa |
| Dry film thickness per coat | 0.4–0.6 mm |
| Total system DFT | 1.0–1.5 mm in 2–3 coats |
| Recoat interval | 6–8 hours at 23°C, 50% RH |
| Active crack-bridging capacity | 2–3 mm crack width |
| Application | Cold-applied liquid; UV-protective topcoat required on exposed areas |
Industry use cases
Residential societies
Terrace recoating on RWA and builder projects where cracked slabs leak into top-floor flats — the crack-bridging film outlasts repeated acrylic repaints.
Commercial podiums
Podium and landscaped deck waterproofing under pavers and planters, where root resistance and seamless detailing around drains are non-negotiable.
Infrastructure
Bridge and flyover deck membranes beneath wearing courses, taking thermal movement and construction traffic during phased works.
Hospitality and landscape
Fountain basins, water features and reflective pools where a jointless lining avoids the leak paths of tiled or sheet systems.
Retrofit contractors
Renovation of post-tensioned and older slabs with live surface cracking, where rigid coatings have already failed once.
Frequently asked questions
Does Aquashield PU need a topcoat on an exposed terrace?
How many coats do I need and how long between them?
Will it bridge cracks that are already in my slab?
How is it different from Dr. Fixit Roofseal or an acrylic coating?
Can it be applied over an old coating?
Does Space Arc apply it or only supply the material?
How we position Dr. Fixit Aquashield PU
Aquashield PU is the premium tier of Dr. Fixit’s terrace waterproofing ladder — specify it when the slab genuinely moves. For sound, crack-free roofs on a budget, Dr. Fixit 201 acrylic does the job at a fraction of the cost; for mid-range projects, bitumen-modified Dr. Fixit Roofseal offers around 300% elongation. Pair any of these with Dr. Fixit PU Sealant for expansion joints and terminations, since a field membrane is only as good as its joints. Where a consultant’s specification calls for a third-party brand, Space Arc also supplies comparable liquid PU membranes from Fosroc’s Nitoproof range and Sika’s Sikalastic line — talk to us with your BOQ and we will match the specified system rather than force a substitution.
Related Waterproofing products
Source Dr. Fixit Aquashield PU for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.