Sarnafil TG66 Ballasted Inverted Roof System

Sarnafil TG66 Ballasted Inverted Roof System

Third party certifications:
  • BBA Agrément Certificate

    BBA Agrément Certificate

    Certificate type

Sika Sarnafil

Flexible Polyolefine (FPO) single-ply membrane for ballasted warm roofs and inverted roofs.

Jump to:
+44 (0)1707 394444

Flexible Polyolefine (FPO) single-ply membrane for ballasted warm roofs and inverted roofs.

System includes:

  • Paving, stone ballast or green/ brown roofs (supplied by others).
  • S-Felt VS 140 filter layer.
  • SarnaTherm XPS insulation.
  • Sarnafil TG66 waterproof membrane.
  • Sarnafil Type A or Type T fleece as cushion layer on suitable deck.

- Filter layer:

A 140 g/m² polypropylene based fleece, grey in colour, suitable for use as an inverted roof filter layer in loose laid ballasted systems. Sarnafil Type VS is UV stabilised and can be left exposed to weather.

- Insulation:

Unfaced extruded polystyrene CFC and HCFC free thermoset cellular plastic insulant, with a rigid closed cell structure. SarnaTherm XPS is manufactured to BS EN 13164 'Thermal Insulation products for buildings - factory made extruded polystyrene foam (XPS)'.

- Waterproof membrane:

Sarnafil TG66 membranes are manufactured using a specially developed in line extrusion coating process. This coats both sides of the glass-fibre carrier simultaneously with a compounded Flexible Polyethylene to produce a dynamically stable membrane, which is suitable for adhered and loose laid ballasted applications.

The process enables between 2% and 5% of recycled material to be used in the production of new membranes.

- Fleece (cushion layer):

A polypropylene fleece used either as a protective layer below the waterproof liner or as a protective layer on top of the liner.

  • Sarnafil Type A: Is not UV stabilised and must not be subjected to external weather conditions for prolonged periods of time.
  • Sarnafil Type T: UV stabilised, can be left exposed to weathering.


Certified by BBA to have a life expectancy in excess of 25 years.


- Filter layer:

Sarnafil Type VS is loose laid, with 300 mm side and end laps.

- Insulation:

The insulation is to be laid loose, with boards lightly butt jointed and level. The specified ballast should be installed as soon as possible, once the filter layer is laid. Until the ballast is laid, the loose laid insulation will be vulnerable to wind uplift forces. If it is necessary to delay ballasting the roof, then temporary ballast, such as bagged gravel or sand, should be strategically placed across the completed roof areas.

Project specific fixing details must be ascertained from the latest Sarnafil project specification.

- Waterproof membrane:

Sarnafil TG66 is intended to be loose-laid and ballasted. Installation is carried out by Sarnafil contractors, who are specifically trained in the installation requirements of Sarnafil T membranes.

- Fleece (cushion layer):

Sarnafil Type A and Type T:

Sarnafil Type A and Type T are generally loose laid, but can be partially bonded to the substrate with Sarnacol 2170 or Sarnacol 2172 if required. In either application, all edges must be overlapped by at least 100 mm.

General information

Uniclass 2015

Ss_30_40_30_79 Single layer sheet inverted roof covering systemsPrimary


J42/120 Inverted roof covering

Specification data - Single layer sheet inverted roof covering systems

Product Reference

Sarnafil TG66 Ballasted Inverted Roof System


Not required

Primer 501




SarnaTherm XPS


Loose laid

Waterproof membrane



Sarnafil TG66


1.5 mm

1.8 mm

2.0 mm


RAL 7040 Window grey


Loose laid

Fleece (cushion layer)

Sarnafil Type A

Sarnafil Type T

Filter layer

S-Felt VS 140


Double LT rainwater outlets

Sarnafil T clean

Sarnafil T prep

Sarnametal T

Sarnaplast 2235

TG/TS rainwater outlets

Standard product features

Filter layer:

  • Thickness: 0.5 mm.
  • Roll width: 2.0 m.
  • Roll length: 50 m.


  • Thermal conductivity: 0.029 W/m²K (thicknesses < 120 mm).
  • 0.031 W/m²K (thicknesses > 120 mm).
  • CFC/ HCFC free.
  • Zero ODP (Ozone Depletion Potential).
  • Typical Density of 33 kg/m³.
  • Compressive strength 300-500 kPa at 10% deformation.
  • Withstands freeze/ thaw cycling.
  • Closed cell structure minimises water absorption.

Waterproof membrane:

- Width

2.0 m.

- Length of roll:

20 m for 1.5 mm thick membrane: 15 m for 1.8 and 2.0 mm thick membrane.

- Weight:

  • 1.5 mm thick: 1.50 kg/m².
  • 1.8 mm thick: 1.80 kg/m².
  • 2.0 mm thick: 2.00 kg/m².

Fleece (cushion layer):

  • Size: 2 x 50 m.
  • Weight: 300 g/m².

Product Options


- Thickness:

Consult Sika Sarnafil for recommendations and details.


  • Double LT rainwater outlets: Insulated outlets.
  • Primer 501: Surface primer creating a key for Sarnaplast 2235.
  • Sarnafil T clean: Cleaning agent.
  • Sarnafil T prep: Seam preparation for use prior to hot-air welding.
  • Sarnametal T: Galvanized metal sheet with Sarnafil T factory laminated to it, for use in prefabricate flashings and drip details.
  • Sarnaplast 2235: Elastic one-part silicone sealant for sealing edges and perimeter upstand flashing terminations.
  • TG/TS rainwater outlets: Injection moulded FPO outlets and scuppers.

Third party certifications
Similar products from Sika Sarnafil