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Langley HM-40 Paratech Hot Melt Roofing System

Langley HM-40 Paratech Hot Melt Roofing System

Langley Waterproofing Systems Ltd Third party certifications:
  • BBA Agrément Certificate

    BBA Agrément Certificate

    Certificate type

Flexible monolithic, elastomeric waterproofing system.

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+44 (0)1327 704778 www.langley.co.uk


Suitable for use in new build projects, where a protected membrane or green roof system is required, including:

  • Flat roofs (including 'zero falls');
  • Protected roofs;
  • Green roofs;
  • Terraces;
  • Podium decks.

Primarily used for concrete substrates, but can also be used on plywood and for a warm (inverted) or cold roof configuration. Protection can be either in the form of polystyrene insulation (warm roof), round washed pebbles, paving/ podium or a green roof system.

Applied via fully-bonded, hot-melt application.


Flexible, monolithic, elastomeric hot-melt bitumen waterproofing system for protected roofs, green roofs, terraces and podium decks.

Features and benefits:

  • Only a single application is required.
  • Robust and durable.
  • Flexible.
  • Root resistant when specified as a green roof (Graviflex (HM) cap sheet).
  • Self-healing.
  • Reinforced with a coated glass mesh for alkaline protection.
  • Permanently elastomeric.
  • Life expectancy for the service life of the roof in which it is incorporated.
  • Quick and easy to install - large areas can be covered quickly.
  • BBA certified.


  • Preparation: Langley Primer (HM).
  • Waterproof covering, first layer: Paratech R Reinforcement (0.11 kg/m²).
  • Waterproof covering, intermediate layer: Paratech HM (3–5 kg/m²).
  • Protective covering, top layer: Paradiene 35 SR4 HM or Graviflex (HM), (4.4–4.6 kg/m²).

General information



Dark grey




40 year

Materials and workmanship.

Uniclass 2015

Pr_35_31_68_38 Hot-applied polymer-modified bitumen waterproof coatingsPrimary


J41/110 Built-up reinforced bitumen membrane warm deck roof covering

J41/12 Reinforced bitumen membrane cold deck roof covering

J41/120 Built-up reinforced bitumen membrane inverted roof covering

J41/130 Built-up reinforced bitumen membrane cold deck roof covering

Product range

Hot Melt Roofing Systems

Specification data - Hot-applied polymer-modified bitumen waterproof coatings Enhanced data


Dark grey.

Horizontal work

Langley Primer (HM).

Preparation Skirtings And Vertical Work

Langley Primer (HM).

First layer

Paratech R Reinforcement (0.11 kg/m²).

Intermediate layer

Paratech HM (3–5 kg/m²).

Top layer

Paradiene 35 SR4 HM or Graviflex (HM), (4.4–4.6 kg/m²).

Surface protection

Graviflex (HM).

Paradiene 35 SR4 (HM).


9.51–9.71 kg/m².


Elongation (to BS EN 12311-1): 45% (maximum).

Impact resistance

Impact resistance (to EN 12691-A): 1000 mm.

Puncture resistance

20 kg.

Static puncture resistance (to EN 12730-B).


550 N/50 mm.

(to BS EN 12311-1).

Overall thickness

7–8 mm (approximately).

Digital objects

Platform Compatible Version Certified to

Revit 2017




Download now from NBS National BIM Library

Third party certifications

BBA Agrément Certificate

Paratech BBA