Dr. Fixit Roofseal Classic — Water-Based Acrylate-PU Hybrid Elastomeric Roof Waterproofing and Heat-Reflective Coating
Nanofibre-reinforced acrylate-PU terrace coating that bridges cracks up to 2 mm, cuts roof surface temperature by up to 10°C and meets ASTM D6083 Type II — supplied and applied by Space Arc across Delhi NCR and Pan-India.
What is it?
A single-component, water-based elastomeric waterproof topcoat from Pidilite, built on acrylate-PU hybrid emulsion technology with nanofibre reinforcement, tested to ASTM D6083 Type II.
Where is it used?
Existing flat and sloped roofs — brickbat coba, cement screed, china mosaic, clay and ceramic tile terraces — along with parapet walls, upstands and rainwater outlet detailing.
Why use it?
300% elongation, 2 mm crack bridging and a Solar Reflectance Index of 105 deliver a leak-free, visibly cooler roof without dismantling the existing waterproofing layers.
How is it applied?
One self-priming coat diluted 2:1 with water at 10–11 m²/L, then two undiluted coats at 2–2.2 m²/L each, the second rolled at 90° to the first, building a 450–500 micron seamless film.
About Dr. Fixit Roofseal Classic
Dr. Fixit Roofseal Classic is Pidilite’s single-component waterproof topcoat for roofs that already exist and already leak. Its acrylate-PU hybrid emulsion pairs the UV stability of acrylics with the stretch of polyurethane, and a nanofibre reinforcement holds the cured film together under thermal movement. The product is tested against ASTM D6083 Type II with published results — 57% solids, 2.1 N/mm² tensile strength and 300% elongation at break — and it doubles as a cool-roof coating, reflecting enough solar radiation to drop peak-summer surface temperatures by up to 10°C. For the countless Indian terraces finished in brickbat coba, screed or china mosaic, it is a practical alternative to breaking the roof open and rebuilding the waterproofing from the slab up.
Space Arc Engineering supplies Roofseal Classic in all five pack sizes with manufacturer batch traceability, and our applicator crews handle the full system — hammer-test survey, screed repair, mesh detailing and pond testing — across Delhi NCR, with material supply Pan-India. Because we distribute several waterproofing brands, our recommendation stays honest: where a roof exceeds the product’s 500 m² limit or needs to carry traffic, we will spec a different system rather than force-fit this one.
The technical insight
The coating works by film coalescence: as water evaporates, acrylate-PU polymer particles fuse into a continuous elastomeric membrane, with dispersed nanofibres acting like micro-rebar that distributes stress across the film instead of letting it concentrate at a crack tip. That is what allows a roughly half-millimetre coating to bridge substrate cracks up to 2 mm (EN 1062-7) and still retain 125% elongation after 1,000 hours of accelerated weathering with no cracking. The film is waterproof yet breathable — a permeance of 17 against an allowable 50 under ASTM D1653 — so residual moisture in old screeds can escape as vapour rather than blistering the coating. The white finish carries a Solar Reflectance Index of 105 (ASTM E1980), which is where the measurable cooling effect comes from.
Where it is used
- Re-waterproofing aged brickbat coba terraces without dismantling the existing coba
- Waterproof topcoat over cement screed flat roofs on homes, builder floors and low-rise societies
- Overcoating china mosaic and ceramic tile terraces where tiles pass the hammer test
- Seamless elastomeric layer over sloped clay tile roofs
- Parapet walls and equipment upstands, coated undiluted in two coats
- Crack bandaging at joints, drain mouths and pipe penetrations with 45 GSM glass fibre mesh
- Cool-roof coating over top-floor slabs to cut peak-summer heat gain
- Detailing around HVAC bases, solar panel upstands and rainwater outlets
Key advantages
- Tested to ASTM D6083 Type II with published results, not just claims — 57% solids, 2.1 N/mm² tensile strength
- 300% initial elongation, retaining 125% after 1,000 hours of accelerated weathering
- Bridges substrate cracks up to 2 mm (EN 1062-7:2004)
- Cool-roof performance: SRI of 105 and up to 10°C lower roof surface temperature in peak summer
- Self-priming and single-component — the primer coat is simply the product diluted 2:1 with water
- Strong bond to concrete: 750 N/m peel adhesion and 2.0 N/mm² pull-off strength
- Breathable, low-water-swelling film (1.4%) reduces blistering risk over old screeds
- Water-based, non-toxic and VOC-compliant, with a 36-month shelf life
Limitations & considerations
- Pidilite restricts it to roofs under 500 m² — larger roofs need a higher-build membrane system
- Cannot be applied directly over expansion or moving joints
- Narrow application window: not below 10°C ambient, not above 36°C surface temperature, and no rain within 24 hours of application
- Rated for light foot traffic only — unsuitable for trafficable podiums, driveways or car park decks
- Not recommended over Kota or kadappa stone, mud phuska or Mangalore tile roofs; glazed non-porous tiles need Dr. Fixit Primer AC first
- Gloss and sheen fade with weathering, and there is no warranty against dirt pick-up on the white finish
Selection & best practice
Surface preparation decides how long this coating lasts. Pressure-wash the roof at a minimum 1,400 psi, treat algae or fungus with a 3:1 bleach solution, and hammer-test coba and tiles — anything more than 30% debonded comes off. Repair hollows and level ponding zones with SBR-polymer-modified mortar, confirm a slope of at least 1:80–1:100 to the drains, and V-cut cracks wider than 0.5 mm before sealing them and bandaging with two coats of Roofseal Classic sandwiching 45 GSM glass fibre mesh. Then apply the self-priming coat (diluted 2:1 with water) at 10–11 m²/L and let it dry 2–3 hours. Follow with two undiluted coats at 2–2.2 m²/L per coat, the second at 90° to the first after 4–6 hours, giving extra coats at corners, outlets and penetrations. Target 450–500 microns DFT, air-cure for 7 days, then pond-test with 50 mm of water for 24 hours before handover.
Specifications
| Chemistry | Acrylate-PU hybrid emulsion, nanofibre reinforced, water-based |
| Standard compliance | ASTM D6083 Type II |
| Solids content | 57% (ASTM D1644) |
| Tensile strength | 2.1 N/mm² (ASTM D2370) |
| Elongation at break | 300% initial; 125% after 1,000 h weathering (ASTM D2370) |
| Crack bridging | Up to 2 mm (EN 1062-7:2004) |
| Coverage | 1.0–1.1 m²/L total system (self-primer + 2 coats, 450–500 micron DFT) |
| Drying time at 30°C / 85% RH | Touch dry 60 minutes; hard dry 4–6 hours |
| Pack sizes / shelf life | 1, 4, 10, 16, 20 litre; 36 months unopened |
Industry use cases
Housing Societies & RWAs
Pre-monsoon terrace re-waterproofing on tower roofs under 500 m², executed block by block with pond-test documentation for the committee.
Independent Homes & Builder Floors
Leak repair over Delhi NCR’s typical brickbat coba terraces without demolition — the most common Roofseal Classic job we run.
Schools & Institutions
Low-odour, water-based application suits occupied campuses; roofs are recoated during vacation windows and cure within a week.
Hotels & Commercial Top Floors
The SRI 105 cool-roof finish trims heat gain into top-floor rooms, easing AC load alongside the waterproofing function.
Renovation Contractors
Bundles neatly into repaint-and-repair cycles: one material handles field areas, parapets and crack bandaging with mesh.
Frequently asked questions
How much Roofseal Classic do I need for a 1,000 sq ft terrace?
Can it be applied over old china mosaic or ceramic tiles without breaking them?
What is the difference between Roofseal Classic, Select and Ultra?
Does it really lower roof temperature?
How soon is it rain-safe, and when do we pond test?
Can I walk on the coated roof or place planters and equipment on it?
How we position Dr. Fixit Roofseal Classic
Roofseal Classic is our default recommendation for residential and small commercial terraces up to 500 m² that need reliable, economical re-waterproofing. Within the Dr. Fixit family, step up to Roofseal Select for the 10-year system or Roofseal Ultra for a thicker PU-hybrid film on harsher exposures; pair parapets and external walls with Dr. Fixit Raincoat, and handle screed repairs with Pidicrete URP. Where the brief changes — trafficable podium decks, roofs beyond 500 m², or membranes under permanent finishes — we move you to heavier-duty liquid systems from our Fosroc and Sika lines, such as Fosroc Nitoproof PU membranes, rather than stretch this product past its design intent.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.