Dr. Fixit Prebond R
A pre-applied, fully-bonded HDPE membrane that becomes part of the concrete itself — built for basements and rafts where water pressure never lets up.
What is it?
A pre-applied, fully-bonded HDPE waterproofing membrane — a UV-resistant, pressure-sensitive-adhesive-coated sheet with a top release liner that is laid down before concrete is poured, rather than a coating applied after.
Where is it used?
Basement rafts, retaining walls, lift pits, and other below-grade RCC structures on new-construction sites, typically specified by structural/waterproofing consultants on basement and infrastructure projects across Delhi NCR and pan-India.
Why use it?
Because it bonds fully to the concrete poured over it, water cannot migrate laterally between the membrane and the structure even if a crack or construction joint develops later — the single biggest failure mode of loose-laid or post-applied basement waterproofing.
How is it applied?
Rolled out over the blinding concrete or excavated face with the release liner facing up; the liner is peeled off in stages just ahead of each pour, laps are overlapped a minimum 100 mm and sealed with Prebond Tape, and structural concrete is then cast directly against the exposed adhesive face so the membrane chemically bonds into the concrete as it sets.
About Dr. Fixit Prebond R
Dr. Fixit Prebond R belongs to Pidilite’s pre-applied, fully-bonded waterproofing membrane range, sold under the “Large Projects” arm of the Dr. Fixit portfolio. The core idea is different from every roll-on or brush-applied waterproofing coating on a typical site: instead of treating a surface after the structure exists, Prebond R is laid down first, on the blinding concrete or excavated face, before the reinforcement cage and structural concrete go in. Its underside carries a pressure-sensitive adhesive layer topped with a UV-resistant gel and protected by a release liner. Once the liner is peeled and concrete is poured directly against the exposed adhesive face, the membrane chemically keys into the setting concrete and becomes an inseparable part of it — there is no interface, gap or air pocket for water to travel along, which is exactly the failure mode that defeats loose-laid or post-applied membranes on rafts and basements.
For a Delhi NCR / Pan-India audience, the product’s real relevance shows up on basements, semi-basements, lift pits, raft foundations, retaining walls cast against shuttering, and metro/tunnel-type work where the water table is high or the site is next to a river, nullah, or low-lying pocket prone to monsoon saturation. In these conditions a coating applied after the concrete has cured can only stop water at the surface — if water finds a crack or a construction joint below it, it can still travel laterally underneath the coating and surface far from the actual defect, making the leak nearly impossible to trace. Prebond R’s fully-bonded, integral-seal construction is built specifically to deny that lateral travel path, which is why specifiers reach for it on basement/raft jobs with sustained hydrostatic pressure rather than on above-grade walls or roofs, where a conventional Dr. Fixit coating (Raincoat, Roofseal, Pidiproof) remains the more practical and economical choice.
The technical insight
The property worth reading closely on the Prebond R datasheet is the gap between the “bare HDPE film” figures and the “composite membrane” figures — a 0.90 mm bare film built up into a >1.2 mm composite. That gap is the adhesive-and-gel layer doing the actual work: it’s what lets the sheet key into wet concrete rather than just sitting under it. A 29 MPa tensile strength and 500% elongation on the bare film matter less for raw strength than for what they let the membrane survive on a live site — rebar being dragged across it, minor differential settlement in the substrate before the pour, or a cold morning pour when a stiffer sheet would crack instead of flex. The 70 m hydrostatic head rating and the -25°C low-temperature pass are both standard-condition ratings under controlled test methods, not site guarantees — they tell you the material itself won’t be the weak point, but the actual as-built performance is set entirely by installation quality, particularly the 100 mm lap and the tape-sealed joints, which is why this category rewards a trained applicator far more than most waterproofing products do.
Where it is used
- Under-raft (blindside) waterproofing for basements and semi-basements before the RCC raft is poured
- Retaining wall waterproofing where concrete is cast directly against the membrane and shuttering
- Lift pits and sump pits below the water table
- Water-retaining and below-grade structures needing a continuous, joint-free membrane
- Metro, tunnel, and underground utility structure waterproofing on large infrastructure projects
- Basement box waterproofing on high-rise and commercial podium construction
- Diaphragm wall and pile-cap waterproofing on deep-basement sites
- Retrofitting new basement extensions cast against existing structures
Key advantages
- Fully bonded to the poured concrete — no water can travel laterally between membrane and structure even if the concrete cracks or settles later, unlike loose-laid or torch-applied sheets
- Cold-applied, factory-controlled composite — no naked flame, torch, or hot-bitumen work on site, which matters on congested urban basement sites in Delhi NCR
- Reinforcement mesh/rebar can be laid directly over the membrane without a protective screed, saving a construction step and a day of site time
- High elongation (500% on the bare HDPE film) lets the membrane accommodate minor substrate movement and settlement without tearing
- Rated to resist a 70 m hydrostatic head, giving comfortable margin over what a typical Delhi basement water table would ever exert
- Passes low-temperature flexibility at -25°C, so the sheet stays workable and doesn’t go brittle on cold early-morning winter pours
- Simple lap-and-seal installation with dedicated Prebond Tape at joints and corners, so crews already trained on one Prebond variant adapt quickly to another
- Backed by Pidilite’s pan-India applicator and dealer network, so warranty and technical support are locally available rather than routed through an importer
Limitations & considerations
- Has to be installed before the structural concrete is poured — it cannot be retrofitted onto an already-cast, leaking basement
- Needs correct sequencing with the structural pour, so it must be planned into the foundation drawings and construction schedule, not decided on-site
- Performance depends heavily on lap and corner detailing — a poorly sealed joint compromises the whole system, and defects only surface after the slab is finished and buried
- Not a substitute for above-grade roof or wall waterproofing coatings — it addresses below-grade hydrostatic conditions, not rain, ponding, or UV-exposed exterior surfaces
- Best handled by a trained, Pidilite-authorised applicator rather than a general waterproofing contractor unfamiliar with pre-applied membrane systems
- Exposed adhesive face should not be left uncovered for extended periods (dust, monsoon exposure) before the concrete pour
Selection & best practice
Treat Prebond R as a structural detailing decision, not a coating choice — it has to go down before the rebar and concrete, so it must be specified and sequenced at the foundation design stage, not added as an afterthought once the raft is already poured. Blind the substrate first (lean/PCC blinding layer), keep it reasonably flat and free of sharp protrusions, then roll out the membrane with the release liner facing up and peel it in stages just ahead of each concrete pour so the adhesive face doesn’t sit exposed to dust and site traffic for long. Overlap adjoining rolls by a minimum of 100 mm and seal every lap, corner, and pipe/rebar penetration with Dr. Fixit Prebond Tape — laps are where the vast majority of on-site failures on pre-applied membranes actually originate, not the membrane field itself. Pre-form internal and external corners as per the manufacturer detail rather than folding the sheet on site, and sequence the pour so concrete goes on within the window the adhesive is designed for — leaving the peeled membrane standing uncovered through a full monsoon spell before pouring is asking for trouble. Because this is a specialist detailing job with real cost-of-failure if lapping is skimped, get it installed by a Pidilite-trained or authorised applicator (Space Arc’s crews are trained on the Prebond range) rather than a general waterproofing contractor working from a photo of the datasheet.
Specifications
| Product type | Pre-applied, fully-bonded HDPE membrane with pressure-sensitive adhesive and top release liner |
| Colour | White / Off-white |
| Thickness — bare HDPE film | 0.90 mm |
| Thickness — composite membrane | >1.2 mm |
| Tensile strength (bare HDPE film) | 29 MPa |
| Elongation at break (bare HDPE film) | 500% |
| Low-temperature flexibility | Pass at -25°C |
| Resistance to hydrostatic head | 70 m |
| Minimum lap/overlap width | 100 mm, sealed with Dr. Fixit Prebond Tape |
Industry use cases
Residential basement construction
Laid under the raft slab of a new basement or semi-basement in a Delhi NCR bungalow or builder-floor project before the RCC pour, to give the below-grade structure a fully-bonded water barrier from day one.
Commercial and high-rise podium basements
Applied across large raft footprints on multi-level basement parking or podium structures, where hydrostatic pressure and joint length make lap-quality control the deciding factor in long-term performance.
Infrastructure and metro-adjacent structures
Specified on underground utility chambers, tunnels, and similar structures where a torch-free, cold-applied membrane is preferred for site safety and where post-construction access for repairs is effectively impossible.
Retaining wall and shoring wall waterproofing
Fixed to shuttering or an existing retaining face so that concrete cast against it bonds directly to the membrane, avoiding the water-track-behind-the-wall problem common with loose-laid systems.
Lift pits and sump pits
Used on pit bases and walls that sit permanently below the water table, where a fully-bonded system avoids the lateral water travel that plagues coating-only treatments in these high-risk, hard-to-access zones.
Frequently asked questions
Is Prebond R the same as ordinary Dr. Fixit waterproofing coatings like Raincoat or Roofseal?
Can Prebond R be used on an existing basement that’s already leaking?
How is Prebond R different from Prebond S or Prebond W in the same range?
Does the membrane need a protective screed after laying?
What happens at the joints between two rolls of membrane?
Is this something a regular waterproofing contractor in Delhi NCR can install correctly?
How we position Dr. Fixit Prebond R
Within Pidilite’s own portfolio, Prebond R sits inside the “Large Projects” pre-applied membrane family alongside Prebond S (granular-surfaced, no-screed variant), Prebond E, Prebond W (hot-air weldable), Prebond Pro, and the companion Prebond DS Tape used for sealing laps and details — all built on the same fully-bonded HDPE principle but differing in surface finish, seaming method, and where on a job they’re best suited. Space Arc stocks and specifies across this range and will recommend the specific variant a given drawing or site condition calls for, rather than defaulting to one SKU. For above-grade waterproofing on the same project — roofs, exterior walls, bathrooms — the correct products are Dr. Fixit’s coating and membrane lines (Raincoat, Roofseal, Pidiproof, Bathseal) rather than anything in the Prebond family, which is purpose-built for below-grade, pre-pour applications only.\n\nOn the competitive side, Fosroc’s Proofex Engage is the genuine equivalent worth naming: it targets the same blindside-basement, pre-applied, fully-bonded use case, though its mechanical-interlock cell-mesh bonding mechanism differs from Prebond R’s adhesive-bond approach. A specifier already standardised on Fosroc’s Proofex range for other reasons would reasonably choose Engage; a site already running Dr. Fixit’s Prebond family for laps, tape, and crew familiarity has good reason to stay within it. Either way, this category is a specialist-installation decision best made with a technical consultant rather than picked off a price list.
Fosroc Proofex Engage — Where a project specification is already written around Fosroc’s mechanically-interlocking (rather than adhesive-bonded) pre-applied membrane system, Proofex Engage is a genuine like-for-like alternative to Prebond R for blindside basement and buried-structure waterproofing.
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