Dr. Fixit Prebond Pro
The pre-applied HDPE membrane engineered for blind-side basements, metro boxes, and rafts that have zero access once the concrete goes in.
What is it?
A pre-applied, fully-bonded HDPE waterproofing membrane with a two-side-lap, double-sided adhesive selvedge that chemically bonds to wet concrete as it cures.
Where is it used?
Basement rafts, blind-side retaining walls, metro/subway station boxes, cut-and-cover tunnels, and other underground structures with no external access after the pour.
Why use it?
Rated to 70 m hydrostatic head with Type A protection to IS 16471:2017 and BS 8102:2009, it stops water tracking sideways under the sheet the way loose-laid membranes can.
How is it applied?
Laid granular-side down on blinding or shoring before the pour; rebar and concrete go straight over it, with adjoining sheets overlapped 75 mm and sealed adhesive-to-adhesive at the selvedge.
About Dr. Fixit Prebond Pro
Dr. Fixit Prebond Pro belongs to Pidilite’s pre-applied membrane range, built to solve a problem ordinary torch-on or liquid waterproofing can’t: how do you tank a basement raft or a wall cast against a piled or shored face, when there’s no external side left to work on once the concrete goes in? The membrane is laid granular-side down against the blinding or shoring, adhesive side up. When structural concrete is poured directly over it, the pressure-sensitive adhesive fuses chemically into the curing concrete, so the sheet becomes an integral, fully-bonded skin on the underside of the slab rather than a loose layer resting against it. That distinction matters: with loose-laid membranes, water finding a pinhole can travel sideways under the sheet for metres before surfacing, making leaks almost impossible to trace. A fully-bonded system compartmentalises any breach to the immediate spot — the “Type A” barrier principle IS 16471:2017 and BS 8102 are built around.
What sets the “Pro” variant apart within Pidilite’s own Prebond family is its two-side-lap, double-sided-adhesive selvedge. Where Prebond S relies on a single adhesive lap and Prebond W needs a hot-wedge weld, Prebond Pro’s overlap bonds adhesive-to-adhesive on both edges, sealing reliably even in wet or muddy conditions where welding equipment struggles — a genuine, practical edge on Delhi NCR metro-box and basement-raft programmes that routinely run monsoon-adjacent schedules.
The technical insight
The number worth noting is the 70 m hydrostatic head rating (ASTM D5385) — roughly 7 bar, well beyond typical NCR or coastal basement water-table pressure, but the margin structural consultants want on buried, unreachable-for-life membranes like metro boxes and tunnels. Puncture resistance of 1000 N (ASTM E154) and lap peel adhesion of 1500 N/m (ASTM D1876) are the two figures site engineers should verify against the delivery TDS, since they’re most exposed to rebar-fixing traffic during the pour. One honest caveat: as of this update, Prebond Pro isn’t listed on Dr. Fixit’s live online TDS library, though it was published and current as recently as 2025 under document code 132. Space Arc procures it against confirmed project orders and cross-verifies the batch TDS with Pidilite before dispatch; if timelines are tight, Prebond S or Prebond W are the currently-catalogued drop-in equivalents in the same family.
Where it is used
- Basement rafts and retaining walls in blind-side construction against secant or sheet piling
- Underground metro/subway station boxes needing Type A protection to IS 16471/BS 8102
- Cut-and-cover road and rail tunnels
- Deep basements in high water-table pockets of Delhi NCR, Gurugram, and Noida
- Lift pits and sump pits below the main raft level
- Diaphragm wall capping beams and secant pile cap slabs on high-rise foundations
- Water and sewage treatment plant substructures below grade
- Any raft pour where post-construction repair access will be permanently blocked
Key advantages
- True chemical bond to the concrete underside, so a pinhole breach stays localised instead of tracking water under the sheet
- Two-side-lap, double-sided adhesive seam bonds adhesive-to-adhesive, sealing reliably even in damp site conditions
- 70 m hydrostatic head rating gives a wide margin over typical NCR water-table pressure
- Granular top-face keys mechanically into concrete for a stronger bond than a smooth-film sheet
- Works on both horizontal blinding and vertical confined-wall faces from one membrane
- Complies with IS 16471:2017 and BS 8102:2009 for Type A protection
- Rebar and concrete go straight over it — no intervening protection screed needed
- 45-day UV tolerance (internal test method) gives slack on phased sites
Limitations & considerations
- Currently off Dr. Fixit’s live TDS library (last confirmed listed in 2025); Space Arc sources it against project orders — confirm availability and lead time early
- Performance depends entirely on lap discipline: 75 mm overlap on horizontal runs, 100 mm minimum at ends and corners — poor site supervision undoes the advantage fast
- The pressure-sensitive adhesive is single-use; a mispositioned sheet can’t be lifted and relaid cleanly
- Not a complete system at movement joints or penetrations on its own — needs Prebond Tape detailing and often a waterstop at real joints
- Requires ambient temperatures of 4°C or above for installation
- As Type A (barrier) protection, IS 16471 and BS 8102 both expect it paired with structural or drained-cavity measures where the below-grade space will be habitable
Selection & best practice
Treat lap and corner detailing as the real waterproofing system, not the sheet alone — most Prebond Pro call-backs Space Arc has inspected trace to a rushed overlap or a folded, untaped corner. Confirm current stock and lead time before locking a pour date, since supply now runs against project orders. Keep the granular face free of mud before the pour; a contaminated bond face is the next most common cause of adhesion failure on-site.
Specifications
| Chemistry / system | Pre-applied, fully-bonded HDPE membrane with pressure-sensitive adhesive and granular top layer |
| Composite thickness | > 1.5 mm (ASTM D3767) |
| Bare HDPE film thickness | > 0.9 mm (ASTM D3767) |
| Tensile strength (bare film) | 25 MPa (ASTM D412) |
| Elongation at break (bare film) | 500% (ASTM D412) |
| Resistance to hydrostatic head | 70 m (ASTM D5385) |
| Puncture resistance | 1000 N (ASTM E154) |
| Lap peel adhesion | 1500 N/m (ASTM D1876) |
| Roll size / standards | 20 m x 1 m or 20 m x 2 m rolls; complies with IS 16471:2017 & BS 8102:2009 (Type A) |
Industry use cases
Metro & mass transit
Underground station boxes and cut-and-cover tunnels on NCR metro corridors, where IS 16471 Type A is a standard tender requirement
Blind-side high-rise basements
Gurugram/Noida towers with secant-piled perimeters, raft and wall cast directly against the piling with no post-pour access
Multi-level basement parking
Commercial and residential basements in high water-table NCR pockets needing a margin above seasonal pressure
Water & wastewater infrastructure
Treatment plant tanks and below-grade structures that must perform for the structure’s full life with no repair access
Lift pits & localised excavation
Sump and lift-pit pours below raft level, applied both horizontally and vertically on the shoring face
Frequently asked questions
What’s the actual difference between Prebond Pro, Prebond S, and Prebond W?
Can it go on vertical walls, or only the raft?
Do we need a protection screed before fixing rebar?
How much water pressure can it withstand?
Is it still available, given it’s off Dr. Fixit’s live TDS page?
How does it compare with a torch-applied bituminous membrane?
How we position Dr. Fixit Prebond Pro
Within Space Arc’s Dr. Fixit range, Prebond Pro sits alongside Prebond S (single-lap, “formerly known as Dr. Fixit Prebond”), Prebond W (hot-weldable), Prebond E, and the Prebond DS/SS Tape accessories used for end laps and repairs — all pre-applied HDPE systems on the same Type A bonding principle, differing mainly in how the lap seals. Staying within the family keeps Prebond Tape compatible across products and procurement simple through one applicator. Where a BOQ specifically calls for Fosroc, Proofex Membrane HDPE-P is a genuine equivalent pre-applied HDPE system for the same blind-side, zero-access scenario with comparable BS 8102/IS 16471 compliance — a specifier might prefer it where Fosroc’s documentation is already the accepted reference on a prior metro or infrastructure package.
Fosroc Membrane HDPE-P — Specifiers on metro or infrastructure tenders that already reference Fosroc’s Proofex Membrane HDPE-P as the accepted below-grade blind-side system may prefer it for documentation continuity, though Prebond Pro’s two-side-lap adhesive selvedge is typically quicker to seal on wet or muddy pours.
Related Waterproofing products
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