Mechanically Fixed

Mechanically fastened systems are suitable for both new and refurbishment projects of any size, proving cost efficient roofing systems for exposed applications.


Ideally suited to projects where wind uplift is high, fast installation is required or the attachment of the existing roofing system is unsatisfactory, mechanically fastened systems are extensively used for large, lightweight metal decked structures such as distribution and logistics centres, warehouses, supermarkets, workshops etc.

Sarnafast Mechanically Fastened Roofing

The Sarnafast system typically consists of a structural deck, loose laid vapour control layer, mechanically fastened thermal insulation and mechanically fastened Sarnafil S327-EL or Sarnafil TS membrane. The Sarnafast system is also suitable for applications without thermal insulation but an S-Felt separation/cushion layer will typically be required.

 

The vapour control layer is generally a polyethylene, such as Sarnavap 500E, 1000E or 2000E, with all overlapping joints sealed with Sarnavap tape. If a bituminous vapour control layer is used, it must be fully adhered to the substrate with self adhesion, synthetic cold bitumen or hot bitumen (if insurance permits the use of this method).

 

A thermal insulation board, meeting the requirements of BS 6229 ‘Code of Practice for flat roofs with continuously supported coverings’, such as SarnaTherm, will be mechanically fastened through the vapour control layer to the substrate, using SBT tubes and SBF fasteners with a SBIW-70x70 pressure plate.

 

Finally, the membrane is loose laid and one side of the membrane is mechanically fastened with SFT tubes and fasteners, using a TP installation tool along the line marked on the sheet, 30mm from the rear edge. The fixing centres required, are calculated by Sika Sarnafil to meet the wind uplift requirements of the project. The following roll of membrane is unrolled over the first sheet by 120mm and the resulting overlap hot air welded with a Sarnamatic automatic welding machine (where required). At all perimeters and penetrations, the membrane is mechanically fastened with Sarnabars or where applicable, SFT tubes.

Sarnabar Mechanically Fastened Systems

A Sarnabar system typically consists of a structural deck, loose laid vapour control layer, mechanically fastened thermal insulation and mechanically fastened Sarnafil S327-EL or Sarnafil TS membrane. The Sarnabar system is also suitable for applications without thermal insulation but an S-Felt separation/cushion layer will be required.

 

The vapour control layer is generally a polyethylene, such as Sarnavap 500E, 1000E or 2000E, with all overlapping joints sealed with Sarnavap tape. If a bituminous vapour control layer is used, it must be fully adhered to the substrate using self adhesion, synthetic cold bitumen or hot bitumen (if insurance permits the use of this method).

 

Thermal insulation board, meeting the requirements of BS 6229 ‘Code of Practice for flat roofs with continuously supported coverings’, such as SarnaTherm, will be mechanically fastened through the vapour control layer to the substrate, using SBT tubes and fasteners with a SBIW-70x70 pressure plate.

 

Finally, the membrane is loose laid and all overlapping joints are hot air welded (prior to the installation of the Sarnabars) at centres calculated by Sika Sarnafil, to meet the wind uplift requirements of the project. The Sarnabars are mechanically fastened using SBT tubes and fasteners, at fixing centres calculated by Sika Sarnafil, prior to being covered with a 200mm wide strip of Sarnafil membrane, hot air welded on both sides.

S327-EL Membrane

Sarnafil S327-EL is a polyester reinforced, multi-layer, synthetic roof waterproofing sheet based on premium-quality polyvinyl chloride (PVC) containing ultraviolet light stabilisers and flame retardant.


Sarnafil S327-EL is a hot air weldable roof membrane, formulated for direct exposure and designed to use in all global climatic conditions. Sarnafil S327-EL is produced with an integral polyester scrim reinforcement for high strength and is used within the Sarnafast or Sarnabar mechanically fastened system.


Sarnafil S327-EL has a unique lacquer coating applied to the top of the membrane to resist staining from airborne dirt and pollutants. Sarnafil S327-EL has no built-in stress at the time of production and has a fully encapsulated reinforcement with no risk to delamination or water-wicking. It is available in a range of colours and thicknesses.


Product Data Sheets

S327-12EL - 1.2mm thick

S327-15EL - 1.5mm thick

S327-18EL - 1.8mm thick


Declaration Of Performance

S327-12EL - 1.2mm thick

S327-15EL - 1.5mm thick

S327-18EL - 1.8mm thick

S327-EL Mechanically Fastened Roof System - Sarnavap 500E

10, 15, 20 & 25 year Mechanically fastened roof covering system:

  • Sarnafil S327-EL waterproof covering.
  • SarnaTherm S insulation.
  • Sarnavap 500E vapour control layer.

 

 

S327-EL Mechanically Fastened Roof System - Sarnavap 1000E

10, 15, 20 & 25 year mechanically fastened roof covering system:

  • Sarnafil S327-EL waterproof covering.
  • SarnaTherm S insulation.
  • Sarnavap 1000E vapour control layer.

S327-EL Mechanically Fastened Roof System - Sarnavap 5000E SA

10, 15, 20 & 25 year mechanically fastened roof covering system:

  • Sarnafil S327-EL waterproof covering.
  • SarnaTherm S insulation.
  • Sarnavap 5000E SA vapour control layer.

TS Membrane

Sarnafil TS is a polyester reinforced, multi-layer, synthetic roof waterproofing sheet based on premium-quality flexible polyolefins (FPO) containing ultraviolet light stabilizers, flame retardants and an inlay of glass non-woven according to EN 13956.

 

Sarnafil TS is a hot air weldable roof membrane formulated for direct exposure and designed to use in all global climatic conditions. Sarnafil® TCS is produced with an inlay of glass non-woven for dimensional stability and a polyester reinforcement for high strength. It is used within the Sarnafast or Sarnabar mechanically fastened systems.

 

Sarnafil TS has no built-in stress at the time of production, excellent dimensional stability and a fully encapsulated carrier with no risk to delamination or water-wicking. Sarnafil TS is available in a range of thicknesses.

 

Product Data Sheets

Sarnafil® TS 77-12

Sarnafil® TS 77-15

Sarnafil® TS 77-18

 

Declaration Of Performance

Sarnafil® TS 77-12

Sarnafil® TS 77-15

Sarnafil® TS 77-18

Sarnafil® TS 77-20

Below Ground Waterproofing?

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