When mechanically attaching single ply membranes to a structure, the interface performance of the structure plus the membrane, fastener and pressure plate performance, are key factors in determining the optimal performance of the finished roofing system.


To ensure that a roofing system's resistance to wind uplift can be correctly calculated, the individual combination of fastener type, membrane type and substrate type, should be tested in accordance with UEAtc directive; “Supplementary Guide for the Assessment of Mechanically Fastened Waterproofing” and Factory Mutual FM 4470.


The results of this test will provide the membrane manufacturer with a design load per fastener, incorporating a safety factor, which can be used when calculating the number of fasteners required to secure the roofing system to the substrate. As this information is generally kept confidential to the membrane manufacturer, it is critical that the manufacturer provides the designer with the design specification, calculated to the relevant British Standard, BS6399- 2 Code of Practice for Wind Loads, or BS EN 1991-1-4 Actions on structures, Wind actions, incorporating the UK National Annex.


To ensure that every Sarnafil roof is designed to stay on the roof the Sarnafil Technical Services Department carries out the wind uplift calculations, using software specially developed by the BRE. The results of these calculations are included in every project specific Sarnafil specification, which provides the Sika Sarnafil Registered Contractor with the information they require for tendering and installing the roofing system. This information is also used by the Sika Roofing Field Technician, to check the on site installation against the original specification, for guarantee purposes.


To ensure the correct fasteners are used in every Sarnafil roofing system, Sika Limited supply a range of Sarnafil fasteners including thermally broken tube fasteners, pressure plates and fasteners, manufactured to our specification by SFS Intec Ltd. This enables Sika limited to provide a Sarnafil guarantee that covers the roofing system* and its attachment, for both product failure and resistance to wind uplift, backed by Product Liability and Professional Indemnity Insurance.


* The roofing system (vapour control layer, insulation, membrane and ancillary components) is only covered if a Sarnafil Extended Products guarantee is used. If a Sarnafil Product guarantee is required, only the waterproofing membrane, its attachment and any ancillary components, are covered.

SFT Tube System

The SFT thermally broken tube systems consists of the SFT tube assembled with the appropriate screw fastener. The SFT tube system is used to restrain Sarnafil S/TCS mechanically fixed membranes, by installing rows of SFT fasteners in the side lap of the sheet, at centres determined by the wind uplift and the deck type.


Product Data Sheet

Sarnafast Tube SFT


Declaration Of Performance

Sarnafast SBF

Sarnafast SBF & Sarnafast Tube SFT

SBT Tube System

The SBT thermally broken tube system consists of a 15mm diameter grey polypropylene SBT tube, assembled with the appropriate screw fastener. The SBT tube system is used to fix Sarnabars when installing either a Sarnafil S/TCS mechanically fixed Sarnabar system or a Sarnafil G/TCG loose laid ballasted system. The SBT tube system is also used in conjunction with the SBIW insulation washer, to fasten mechanically fixed insualtion.


Product Data Sheet

Sarnabar Tube SBT


Declaration Of Performance

Sarnafast SBF & Sarnabar Tube SBT

Sarnafast SBF & Sarnafast Insulation Washer DTL

Sarnafast SBF & Sarnabar Tube SBT & Insulation Washer SBIW