Loose laying with mechanical fastening

For loose-laying membranes with mechanical fastening, all layers of the roof structure are firmly anchored to the supporting structure in a single operation. If it is not certain that the insulation sheets will be kept in position by fixing the overall structure, additional mounting of the thermal insulation is necessary. With trapezoidal steel profiles, the insulation sheets should be laid so that their long sides are at right angles to the top corrugations. The insulation boards should be thick enough so that the lower corrugation is not impacted or penetrated when walked upon (see flat roof guidelines 9/2001, table 1, recommended minimum thickness of trapezoidal profiles).

Asymmetrical fastening

The seam joint provides a seal and at the same time holds the membrane in position. Fastening takes place at the edge of the membrane. The fasteners should be placed at equal intervals and parallel to the edge of the membrane. Membrane overlap should be 11 cm.

Symmetrical fastening: strip welding / fastening system

a) Both parallel membranes overlap by at least 8 cm and are not welded. The fasteners are arranged evenly in the middle of the overlap. A strip of material (15-25 cm wide) is used to seal the area around the fasteners on to the existing surface sealing.

b) This system is also used in lightweight roof construction to form the edge and corner regions in the longitudinal direction of the corrugations. The fasteners are arranged as prescribed along the laid membrane and covered with 15-25 cm wide strips of material.

Fasteners

For fasteners, only use self-drilling screws, woodscrews or anchor systems (with the appropriate load distribution discs) that have been tested and approved for this application. The systems need to be corrosion-protected and made of non-ferrous metals or non-ageing and heat-resistant plastic.

Fasteners include:




Caution: sealing membranes may not be fastened with nails. Do not use nails!

Laying on trapezoidal steel profiles

Membranes should be laid on trapezoidal steel profiles at right angles to the upper corrugations. For edges and corners, narrow membranes (52.5 cm wide) are used to accommodate more fastening points. ExtruBit/ExtruPol roofing and sealing membranes come in type M 1.05 m and type MK 1.50 m. Both types can be laid in the central area. Type M (1.05 m wide) or MK (1.50 m wide) ExtruBit/ExtruPol roofing and sealing membranes can be laid in the central area. Edge and corner regions are laid in a longitudinal direction to the corrugations using additional fasteners as shown in the diagram below. Additional fastening points are covered with strips (approx. 20 cm wide).t.

Number of fastening positions
Wind uplift forces are determined according to DIN 1055, part 4. The calculations are based on the length, width and height of the building. When calculating, a distinction is made between the central, edge and corner regions. Individual calculations in accordance with DIN 1055, part 4, are necessary to determine the minimum number of fasteners for buildings exposed to high winds (e.g. in coastal regions), internal pressure or for those over 20 m high. This applies to enclosed buildings and non-windy locations.The values extracted during reconstruction need to be determined. Wind load calculations are part of SCHEDETAL?s services and help reduce costs.

Please note: it is essential to observe wind load calculations conducted by SCHEDETAL if they diverge from the normally applicable guidelines. If fewer fasteners are employed than the number calculated, a properly functioning system cannot be guaranteed.