Proofex Engage - Cast in-situ waterproof membrane

Cast in-situ waterproof membrane. Protects concrete from attack from chemicals and aggressive ground salts. Bonds permanently to concrete. A comprehensive range of auxiliary products is available to simplify the application process.








Proofex Engage is a unique patented system that is formed by a mesh attached to a polyethylene membrane that allows the poured concrete to adhere to it forming a firm mechanical bond.

Proofex Engage serves as a barrier against water, water vapor and gases and protects concrete from subsoil salts, chemicals and hydrocarbons.

Proofex Engage comes with a non-mesh end that facilitates overlap. A wide range of auxiliary products are available to facilitate the application process.

Proofex Engage serves as a barrier to water and building gases and civil works structures.


  • Resistant to attacks of chemicals and aggressive salts of the subsoil
  • Methane and CO2 protection as defined in BRE Report 212 and radon as defined in BRE Report 211
  • It forms a firm mechanical bond with the poured concrete remaining attached to the concrete in the event of a land settlement
  • Simple application - no primer or protective material required
  • Inert product - there is no risk of reaction with standing water before the concrete is poured
  • Durable - withstands the weather and resists damage from the construction process.
  • Can be transited immediately after application
  • BBA Certification


Proofex Engage has been approved by the British Board of Agreement, certificate nº 03/4042.

BS EN 13967: 2004 - Flexible sheets for waterproofing. Plastic and rubber anti-peeling sheets used for sealing buried structures. Type A and Type T.

It complies with the requirements of British Standard 8102: 1990 - good practices for "Protection of structures against groundwater". Classes 1, 2 and 3.

EN 13967: 2004 - Flexible sheets for waterproofing. Rubber and plastic film, including plastic and rubber sheets used for the sealing of buried structures:

  • Class: Type A and Type T
  • Watertightness: Pass
  • Impact resistance> 1,5 m
  • Hazardous substances Conforming with 5.17

How to use

Preparation of substrate

Horizontal application - the membrane will be installed on a smooth substrate. The ideal is a ready-mixed concrete but can also be placed on a suitably compacted granular substrate. The substrate will be free of loose particles. Eliminate stagnant water to prevent contamination of overlaps and waterproofing properties are not affected.

Vertical application - the membrane is installed on the formwork or adjacent structures.

Membrane Installation

Cut the membrane to the required length for installation. Carefully unroll it with the mesh upwards. Place the adjacent membranes so that they overlap 75 mm along the adhesive tape. When two adjacent whole rolls are placed, there must be a half roll length space to prevent the accumulation of final joints in the same area.

End joints and membrane edges - make a Proofex Engage butt joint to the Proofex Engage Detail Strip. The top of the joint can be subsequently sealed with Proofex LM reinforced with Proofex LM Mesh. This overlap must extend 75 mm on each side of the joint that has been formed. All overlaps and joints should be firmly compacted to ensure complete adhesion between layers.

Horizontal and vertical joints - overlap Proofex Engage with L-shaped profile and over 40mm with Proofex LM, which can be reinforced with Proofex LM Mesh.

In cold or wet conditions, the adhesive that is placed on the edge of the membrane can recover tackiness by cleaning it with Fosroc Solvent 501.

Proofex Engage Detail Strip can be heated with a blowtorch or heat gun to remove moisture and facilitate initial bonding. This procedure will also be used to bend the Proofex Engage 90 ° in a wall-to-floor transition.

Removal of formwork

If the membrane has been installed on a formwork, it is recommended that the concrete achieve a minimum compressive strength of 10 N / mm2 before dismantling the formwork.

Passing elements

Proofex Engage piping entrances require special attention. Recommended for these details Proofex Top Hat used in conjunction with Proofex Total Tape and Nitoseal MS60. For more information, contact the Technical Department of Fosroc.

Filling material

If filler material is used, it should not contain sharp objects that could damage the Proofex Engage sheet. The filler material must not contain bricks, blocks or stones larger than 50 mm.

Contaminated land

Proofex Engage can be used in applications where the base is contaminated with hydrocarbons, salts etc.

Contact the Fosroc Technical Department for more information.

Additional Products

Proofex LM

A two-component liquid membrane for sealing around complicated details such as pipe inlets, protrusions, pile heads, etc.

Corner pieces

125 mm inner and outer corner pieces made with polyethylene membrane with one end without mesh in butyl base of 100 mm.

Proofex L-Profiles

Polyethylene section 5 mm long by 250 mm wide with two ends without mesh in butyl base. It is used by doubling its length 90º in transitions between horizontal and vertical membranes to give continuity to the waterproofing. Also use the preformed parts. The Proofex L-profile is supplied with a butyl locking strip at each end. If the L-shaped profile is cut, the strip should be replaced with Proofex Engage Detail Strip.

Proofex Engage Detail Strip

Reinforced double-sided waterproof adhesive tape to seal and join the end joints and edges of the membrane. They are sold in packs of two. It consists of a resistant fabric of synthetic fiber impregnated and coated on both sides with bituminous adhesive and protected with siliconized paper.

Proofex Mesh LM Mesh

Reinforcement mesh used together with Proofex LM for heavy load areas (segments and pipes).

Proofex Top Hat

MDPE coating, which encapsulates a layer of aluminum tape.

Proofex Total Tape

It is used to adhere Proofex Top Hat to Proofex Engage and as "L" profile closure strip.

Nitoseal MS60

Used as a sealant between Proofex Top Hat and pipe protrusions


Store the product horizontally in a dry place in its original and closed container, away from sunlight.

The "L" profiles must be stored vertically. Do not deform or crush the roll.


Under working conditions below 5 ° C Proofex Engage can be applied normally if the following precautions are taken: apply heat to all the adhesive and store the material and proceed to their mixing in an air-conditioned place.


Safety and hygiene

There are no health hazards associated with Proofex Engage under normal conditions of use.

For more information, consult the Material Safety Data Sheet.


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