Mechanically Fastened Flat Roofs

Mechanically fastened systems are suitable for both new and refurbishment projects of any size, providing 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.

mechanically fastened roof

Types of Mechanically Fastened Single Ply Membranes

Sarnafil PVC Membrane (S327-EL)

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. The membrane is produced with 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. It 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.

Sarnafil FPO Membrane (TS)

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. It 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.  

The membrane 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.

Fixing Systems

The Sarnafast system typically consists of a structural deck, loose-laid vapour control layer, mechanically fastened thermal insulation and mechanically fastened Sarnafil S327-EL (PVC), or Sarnafil TS (FPO) membrane. It lends itself to large projects, and is the fastest of the Sarnafil mechanically fastened roof systems to install. The Sarnafast system is also suitable for applications without thermal insulation, but a felt separation/cushion layer will typically be required.

The membrane is loose-laid, and one side of the membrane is mechanically fastened with SFT tubes and appropriate fasteners. The roll of membrane
is unrolled, ensuring a minimum 120mm overlap, which is then hot-air welded to the previous sheet with a Sarnamatic automatic welding machine
(where required).

Sarnabar Fixing System

A Sarnabar system typically consists of a structural deck, loose-laid vapour control layer, mechanically fastened thermal insulation, and mechanically fastened Sarnafil S327-EL (PVC), or Sarnafil TS (FPO) membrane. It lends itself to the small to medium size projects, where wind uplift has dictated that the Sarnafil roof system needs to be mechanically attached. The Sarnabar system is also suitable for applications without thermal insulation but a felt separation / cushion layer will be required.

The membrane is loose-laid and all overlapping joints are hot-air welded. The installation of the Sarnabars then follows, at centres calculated by Sika Sarnafil to meet wind uplift demands of the project. Sarnabars are secured to the roof deck using SBT tubes and appropriate fasteners, before being weathered with a 200mm wide coverstrip, hot air welded on both sides.