Delta FM – Cavity Drain Membrane

Delta FM damp proof membrane

Delta FM is a Virgin High Performance PE-VHD.  Specifically designed for floor applications to combat capillary dampness and contamination.  The low stud profile (4 mm) minimises the impact upon existing floor levels but still provides an air gap to achieve damp pressure equalisation. The special low profile offered by Delta FM is excellent for detailing existing staircases and tight spaces. Delta FM can be linked to other Delta MS membranes.

A fast-track application which allows for various floor finishes to be achieved with zero ‘down time’.

  • Type C Drained Protection in accordance with BS 8102:2009
  • BBA Approved
  • Fast track application
  • RH Levels are isolated in the air gap and controlled.
  • A reversible system, which will minimDelta FMize damage to historical or heritage structures
  • Virgin high density polyethylene studded/moulded sheet (HDPE)
  • An effective barrier to the transmission of salts, liquid water and water vapour

NBS Specification J40 (Clause 290) Flexible Sheet Tanking/Damp proofing.  BS 8102:2009 Type C Drained Protection.

Ancillary Products

Delta FM Rolls 1Our ranges of ancillary products work as the perfect compliment the Delta FM Cavity Drain System, allowing for application on different substrates and surfaces both sealing and dealing with protrusions and condensation. We recommend:

Delta FM is a fast-track application which allows for various floor finishes to be achieved with zero ‘down time’. Delta FM can be used in new build, remedial or refurbishment projects for floors and walls.

Delta FM can also be used in conjunction with thermal installation, sound insulation and numerous types of underfloor heating systems.

Delta FM is suitable for use on damp proofing walls, floors and vaulted ceilings, above and below ground, in new construction or in existing buildings over a contaminated or damp background. It can support a dry lining, screed or flooring, in the following situations:

  • on damp floors in situations subject to perennial moisture
  • in conjunction with a remedial DPC Systems where the walls and floors have a high salt content and/or it is necessary to complete the installation immediately without allowing a period for initial drying
  • over walls and floors which have a friable or painted surface, are contaminated (eg with oil or mould), or have a high salt content
  • as a waterproofing membrane in areas subject to vibration.

Depending on the application required and the site conditions, the membrane may be used as:

  • an underfloor damp-proof membrane
  • a dry lining for walls, ventilated into the room via aeration slots at the top and bottom of the wall or via passive air vents, where access through an external wall is available
  • a sealed system covering wall, floor and ceiling with provision made for disposing of water build-up behind the membrane via a sump and pump.


 Technical Drawings
View Data Sheet BBA Certificate
Product code:DMS023
Material:Virgin high-performance high-density polyethylene
Temperature Resistance:-30degC / +80degC
Thickness:approx. 0.6 mm
Stud Height:approx. 4.5 mm
Roll Size:2m x 20m
Compressive Strength:Approx. 700 kN (=50 t) / m²
Chemical Properties:Excellent chemical resistance; No root penetration; rot-proof; approved for drinking water applications
Behaviour in Fire:Class E

If you'd like more information on any of our products, call 01992 523 523 today to speak to one of our experts