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ANTI-CON SHEETING

Is used for profile sheets on roofs which can be subject to condensation on the underside and prevents dripping in such cases

Typical buildings are:

  • Uninsulated Warehouses
  • House extensions
  • Garages - Car ports
  • Parapet roofs
  • Agricultural Building
  • Open Shelters

Product :

Anti-Con is a precoated steel sheet with moisture absorbing fibre fabric on the underside. This can be applied to any of our large range of profile sheets for roofs.

The moisture absorbing function :

Condensation on the underside of the profile sheets occurs when the temperature of the sheet is equal to or lower than the dew point of the air under the sheet. The fibre fabric has the capability to absorb at least 800-1000 grams of water per square meter (depending upon pitch of roof) which is considered to be more than sufficient for most applications. Between the condensation periods the fibre fabric dries out. For this reason the building must be ventilated.

top sheet with a strip of absent fibre
Figure 1. Strip of absent fabric at the sidelap

 

Properties for the fibre fabric :

Substrate:
Polyester fabric with an admixture of cellulose fibres and acrylic binder.

Surface weight:
80 g/m2

Tolerance, absent width:
+7/-0 mm

Thickness:
415 um

Moisture absorption:
Adapted to normal requirements.(measured by condensation tests and found to be at least 800-1000 g/m?) depending on pitch of roof.

Colour: Marble

Detail Design of Roofs

Profiled sheets with Anti-Con are installed in the same way as sheets without fibre fabric with some exceptions.Due to the capilliary action properties of the fibre the following precautions MUST be made to prevent that water is drawn back under the sheet at lower sheet tails and at endlaps.

- Lower sheet tails and the topsheet at endlaps should be painted with a transparent impregnating liquid or alkyd lacquer. See fig. 2

diagram of transparent lacquer coating
Figure 2. Painting with transparent lacquer

Caution

Anti-Con should not be installed directly on water absorbing materials, for instance timber purlins. In such cases the timber should be covered with a strip of asphalt felt or similar material.

At roofpitches lower than six degrees we advise that the bottom of the profile is bent down to form dripspouts. See fig. 3

Dripspout and transparent lacquer coating
Figure 2. Dripspout at lower sheet tail

See that the interior of the building or the space under the roof is well ventilated, in order to insure that the absorbed moisture will in due course evaporate from the fibre fabric coating.

Installation

At installation be careful not to damage the fibre when transporting the sheets over purlins. It is natural that the porous surface of the fibre can be easily soiled. Use therefore clean working gloves when handling the sheets.

DO NOT walk on the fibre before installation !

Classifications

Both topcoating and the fibre fabric have class I fire-resistant surface as per BS 476 Part 7. The fibre fabric is frost resistant and resistant to mould growth.

Limitations of the product

The use of polyester coating in a distinctly marine location i.e. within 300 meters of open coast, will mean that inspection of the polyester topcoat needs to take place at more regular intervals. i.e. every two years.

Repainting will also be necessary earlier and will depend upon the inspection results. Use of Anti-Con for animal housing will lead to ammonia on the underside of the sheet which will restrict the total sheet life.

Repair of top coating and fibre fabric

Any darmage to the coating during handing should be repaired. Major damage on the fibre fabric can be remedied by bonding a new fibre fabric to the underside. A water resistant adhesive can be used.

Technical service and information

Further information can be obtained from CSL

Miscellaneous

Care should be taken to avoid damage to the coating during profiling and installation. Storage of the material outdoors should be avoided. However, if this is unavoidable, the material should be satisfactorily covered and should be stored in a manner that will ensure good air circulation, in order to avoid accumulation of moisture.

For particulars of tolerances and characteristics in general, please refer to the relevant European and ECCA (European Coil Coaters Association) standards