Membranes have a mixed reputation in structural waterproofing. They provide full-area protection – but if a conventional sheet becomes leaky, water migrates between membrane and concrete and emerges somewhere inside, far from the actual point of ingress. The fresh-concrete bonded system RASCOguard FBV overcomes exactly this weakness. How? By making the membrane not adjacent to the concrete, but one with it.
The Fundamental Problem of Conventional Membranes
A conventional waterproofing sheet is placed against the concrete, but does not bond with it. A hair-thin gap remains between sheet and structure. As long as everything is watertight, that does not matter. But if damage occurs at one point – a puncture, a poorly welded seam, a crack in the concrete – water finds its way into precisely that gap. And there it migrates. The leak visible inside is often located metres from the actual point of ingress. The consequence: laborious leak tracing, in the worst case excavation. Specialists call this phenomenon water tracking – water travels behind the waterproofing layer. It is the classic Achilles heel of every loosely laid membrane.How RASCOguard FBV Solves the Problem: the Bond
RASCOguard FBV is a fresh-concrete bonded system. The decisive difference lies in the word “bonded”. The sheet is laid before concreting – with the TPO/FPO top layer facing the ground and a special bonding zone of PP fibres facing the future concrete. When the fresh concrete is placed, it interlocks mechanically and adhesively with this fibre layer. After hardening, the membrane is inseparably bonded to the structure. The result: there is no longer a gap in which water could migrate. Even if the sheet were locally damaged, the damage remains contained – water cannot spread behind the waterproofing. This property is called water-tracking resistance, and RASCOguard FBV achieves tested values of at least 900 kPa.
Technical Data at a Glance
RASCOguard FBV is available in two thicknesses – FBV12 (1.2 mm membrane thickness) and FBV08 (0.8 mm). Both are CE-certified to EN 13967 and tested by notified body KIWA.
Property | RASCOguard FBV12 | RASCOguard FBV08 |
Membrane thickness | 1.2 mm (total approx. 2.1 mm) | 0.8 mm (total approx. 1.7 mm) |
Water-tracking resistance | ≥ 900 kPa | ≥ 900 kPa |
Watertightness | 500 kPa / 72 h tested | 500 kPa / 72 h tested |
Long-term water pressure | ≥ 900 kPa / 17 days | ≥ 900 kPa / 17 days |
Crack bridging | up to 20 mm | up to 20 mm |
Temperature resistance | −40 °C to +120 °C | −40 °C to +120 °C |
Maximum tensile force (MD) | ≥ 750 N / 50 mm | ≥ 540 N / 50 mm |
Two values are particularly noteworthy: at 1 mm crack opening, the system withstands a water pressure of over 9 bar; at larger crack openings of 3.2 to 5 mm, still 6.9 bar. And the tested crack bridging of up to 20 mm applies under both static and dynamic loading – the system therefore handles structural elements that move.
The Three Methods in Direct Comparison
Criterion | Injection | Conventional Membrane | Composite System (FBV) |
Mode of action | Pinpoint injection | Loosely laid barrier | Barrier bonded to concrete |
Water tracking possible | Not applicable | Yes | No, water-tracking resistant when correctly installed |
External access required | No | Yes, fully | No, laid before concreting |
Existing-structure remediation | Very well suited | Difficult | Not suitable (new build) |
Retroactively adjustable | Yes, re-injectable | No | Limited |
Use under water | Yes, with PU resins | No | No (laid in dry conditions) |
Ideal for | Remediation, localised damage | Simpler new-build structures | Planned area waterproofing, new build |
Two values are particularly noteworthy: at 1 mm crack opening, the system withstands a water pressure of over 9 bar; at larger crack openings of 3.2 to 5 mm, still 6.9 bar. And the tested crack bridging of up to 20 mm applies under both static and dynamic loading – the system therefore handles structural elements that move.
More Than Water: Radon, Chemicals, Salts
RASCOguard FBV does not seal against water alone. Thanks to the chemical resistance of the TPO/FPO membrane, the system also acts as a reliable barrier against further influences:
Radon: The naturally occurring, health-hazardous noble gas is reliably retained – relevant wherever occupied rooms lie below ground level.
Chemicals: Tested resistance to calcium hydroxide, sulphurous acid and sodium chloride – suitable for alkaline environments and saline groundwater.
Salts and micro-organisms: Resistant to root penetration, micro-organisms and salt loading. The material is also environmentally sound: the limit values of the German Federal Soil Protection Ordinance for the soil-groundwater pathway are met, and the system is classified as environmentally compatible under REACh and M Geok E.
The System: Sheet, Sealing Strips, Tape/Or
RASCOguard FBV is not a single product, but a coordinated system. The best sheet is of little use if the details – corners, penetrations, transitions – are not addressed with equal care. Three components work together:| Component | Function | Application |
| RASCOguard FBV | Fresh-concrete bonded sheet (TPO/FPO) | Area waterproofing of floor slabs, walls, precast elements |
| RASCOguard DBI / DBA | FPO sealing strips, internal and external | Tie bolt locations, butt joints, repair of defects |
| RASCOguard UTV | Universal tape with fleece | Transitions, penetrations, connections to third-party systems |
Where RASCOguard FBV Sits in the RASCOR Portfolio
With RASCOguard FBV, RASCOR extends its waterproofing range with an important addition. The question is not “composite membrane or White Tank?” but: which system suits which project – and how do they complement each other? As a complementary measure to the White Tank. RASCOguard FBV can be selectively combined with WR concrete structures – for example for additional protection over construction and crack-inducer joints or under particularly high hydrostatic pressure. The system is compatible with WR concrete consistency classes F2 to F6 as well as lightweight and self-compacting concrete. As a standalone area waterproofing system. For floor slabs, foundations, external walls and precast concrete elements in above-ground, civil and tunnel construction, RASCOguard FBV is a fully fledged waterproofing solution. Where injection does not apply. Injection technology remains the first choice for retrospective waterproofing and existing-structure remediation. RASCOguard FBV is its counterpart for planned area waterproofing in new builds – the two approaches complement rather than compete with each other.Practical Advantages on Site
Workable on damp substrates: as long as no standing water is present – making the system more weather-tolerant than many alternatives.
Wide temperature window: thermal jointing down to −10 °C, system adhesive bonding from 0 °C.
Visual inspection before concreting: joints and transitions can be checked and reworked before the concrete is placed.
Robust material structure: high impact resistance and tear propagation resistance protect the sheet during the construction phase.
Frequently asked questions on RASCOguard FBV
What is a fresh-concrete bonded system?
A fresh-concrete bonded system is a waterproofing sheet laid before concreting that bonds firmly to the structure as the concrete hardens. This creates a full-area, water-tracking-resistant bond – unlike loosely laid membranes, where water can migrate between sheet and concrete.
What does water-tracking resistant mean?
Water-tracking resistant means that water cannot migrate between the waterproofing sheet and the structure. With RASCOguard FBV, the fresh concrete interlocks with the bonding zone of the membrane, so no continuous gap forms. Any potential damage therefore remains locally contained. Tested value: at least 900 kPa.
What water pressure does RASCOguard FBV withstand?
The system is tested against hydrostatic pressure. At 1 mm crack opening it withstands a pressure of over 9 bar; at crack openings of 3.2 to 5 mm, still 6.9 bar. Long-term testing confirmed at least 900 kPa over 17 days.
Does RASCOguard FBV also protect against radon?
Yes. The TPO/FPO membrane acts as a reliable barrier against the radioactive noble gas radon. This is particularly relevant for occupied rooms below ground level in radon-affected regions.
Can RASCOguard FBV be combined with WR concrete?
Yes. RASCOguard FBV is designed as a complementary measure to WR concrete structures and is compatible with WR concrete consistency classes F2 to F6 as well as lightweight and self-compacting concrete. It is used, among other applications, for additional protection over construction and crack-inducer joints.
Which standard applies to RASCOguard FBV?
RASCOguard FBV is CE-certified to EN 13967, the European standard for waterproofing sheets. Testing was carried out by notified body KIWA. RASCOguard FBV12 additionally meets the requirements of DIN/TS 20.000-202 and therefore DIN 18533 for structural waterproofing.
What are RASCOguard DBI, DBA and UTV for?
These are the system components for details. RASCOguard DBI and DBA are FPO sealing strips for internal and external connections, butt joints and repairs. RASCOguard UTV is a universal tape for transitions, penetrations and connections to third-party systems.
Conclusion:
RASCOguard FBV answers the most important criticism of membrane waterproofing: through the full-area bond with the concrete, water can no longer migrate behind the waterproofing layer. Combined with the tested hydrostatic pressure resistance, crack bridging of up to 20 mm and the barrier effect against radon and chemicals, the result is a waterproofing system that harnesses the strengths of the membrane without inheriting its classic weakness. For RASCOR, it is a logical portfolio extension – planned area waterproofing for new builds, coordinated with the proven injection and White Tank expertise.
Are you planning a structure and considering whether RASCOguard FBV is the right solution?
The RASCOR team advises on the right system choice. Contact: +41 44 857 11 11 or sales@rascor.com.