Mechanically fixed single ply roofing system offers a fast-track method of application ideally suited to exposed locations and high wind loads.
In mechanically fastened systems the single ply roof membrane is secured to the roof deck with using mechanical fixings to restrain the membrane against wind uplift forces
Sureplan FPO reinforced membrane
- Sureplan FPO.
- Icopal Membrane Tubular Washer.
- Icopal Insulation Tubular Washer.
- Thermazone insulation board.
- Vapour Control Layer.
- Structural deck.
is fastened in the overlap seam along one edge of the membrane and secured directly to the structural deck. The adjacent sheets of membrane are then hot-air welded together with a hot-air welder to provide a continuous waterproof covering.
The membrane is protected from mechanical damage from the screw head by using an Icopal Tubular Washer or Icopal Stress Plate in conjunction with the appropriate screw fastener.
For confirmation of the appropriate size of washers and fasteners to use, refer to the Icopal Fastener product datasheet.
The single ply membrane must be secured at the correct fastener centres, calculated in accordance with BS EN 1991: Parts 1–4 to determine the correct fixing centres specific to the project.
The single ply membrane will require closer fixing centres at higher risk roof areas, such as in corners and at roof perimeters.
Mid-sheet fixings may be required dependent upon the results of the wind uplift calculation. These additional fixing points are therefore strapped with a section of membrane and hot-air welded on each side of the fixing line.
Where the substrate comprises profiled metal sheet, the waterproof membrane should be fixed at right angles to the longitudinal rib of the metal profile.
Icopal Screw Fasteners and Washers
Icopal supply a range of specialist fasteners for securing thermal insulation and Sureplan FPO membranes to a variety of structural roof decks including steel, concrete and timber.
Icopal Tubular Washers eliminate all thermal transmittance associated with metal fasteners, thereby allowing reduced thicknesses of insulation. They are designed with a low-profile washer and narrow tube diameter which aids installation and improves aesthetics.
Icopal Screw Fasteners are manufactured from high grade carbon steel which are case hardened to achieve the properties essential for long term performance and have an organic corrosion resistant finish to meet UEAtc Part 2 requirements.
Regardless of the type of membrane attachment, mechanical fasteners are always required at the roofs perimeter, angle changes and any details. This ensures that any tensions generated in the field membrane are not transferred to other areas.
Thermal insulation boards should be independently mechanically fastened to the structural deck. The number of fixings and the application pattern is dependent upon the size and type of insulation board.
Icopal recommends that insulation boards should be secured at a rate of 11 fasteners per 2400mm x 1200mm (3.8 fixings/m²).
Icopal offers a range of thermal insulation boards.
Typical insulation board used: Thermazone Foilboard or Thermazone Roofboard