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A combination of Premcrete Maxiprufe Plus and Premcrete Hydroprufe 6000 Flexi. This formulation is a lightweight, pre-applied, self-healing and gas resistant membrane which utilizes Premcrete APAN™ technology to resist a hydrostatic head of water pressure.

The six-layer polyolefin layer is reinforced with a 12-micron aluminium foil core to restrict the gas vapour transmission rate to less than 40 ml/m²/day, in accordance with BS 8485:2015. The self-healing properties of the hydrophilic, water-reactive polymers secure the integrity of the membrane, which is unaffected by the presence of contaminants in the groundwater.

Features and benefits:

  • Lightweight, flexible and robust membrane.
  • Easily installed.
  • Good chemical resistance.
  • Highly tear resistant.
  • Self-healing in the event of puncture.
  • Forms a strong adhesive bond to concrete.
  • Complies with BS 8485 and BS 8102 to provide complete protection against VOCs, hydrocarbons, carbon dioxide, radon and methane.


Suitable for use as a pre-applied waterproofing and gas-proofing membrane for the following:

  • Type A basement constructions, grades up to and including Grade 3.
  • Sub-structures, providing protection against hydrostatic water pressure and ground gases.

Can also be used at ground level as a loose-laid membrane.

Ancillary components:

Can be used with the following to create a complete membrane solution:

  • Combi-Tape.
  • Twinseal Compound.
  • Maxiprufe Metal Washer Fixings.
  • Hydroseal FX.
  • Hydrostop BR.
  • Hydrostop WS10.
  • Hydrostop WSM.
  • Cemflex VB.
  • Hydrobar PVC.

Combi-Seal Plus should not be installed above intended final ground level.

Related literature

The following content references this product:

Standard product features


3 mm (20 kPa).

Roll size:

2 x 10 m.


950 g/m².

Technical characteristics:

  • Maximum tensile strength, machine direction (MD) (to DIN EN ISO 12311-2): 621 N/ 50 mm.
  • Maximum tensile strength, cross-direction (CD) (to DIN EN ISO 12311-2): 1100 N/ 50 mm.
  • Elongation at break MD (to DIN EN ISO 12311-2): 32%.
  • Elongation at break CD (to DIN EN ISO 12311-2): 30%.
  • Tear resistance (nail shank) MD (to DIN EN 12310-1): 500 N.
  • Tear resistance (nail shank) CD (to DIN EN 12310-1): 510 N.
  • Water tightness (to DIN EN 1928 B): Pass.
  • Resistance to impact (to DIN EN 12691): Pass.
  • Gas vapour transmission (to BS 8485): 40 ml/m²/day.
  • Moisture/ vapour transmission rate: <0.01 g/m²/day.
  • Methane permeability (to ISO 15105-1): <0.1 ml/m²/day.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-65-50/325 Plastics sheets

Product specification

An important note about specifying





+44 (0)800 619 1619

Product reference

Combi-Seal Plus

Manufacturer details

Seymour House,
Mayflower Close,
Chandlers Ford,
Hampshire, SO53 4AR
Tel +44 (0)800 619 1619
NBS Plus