COP v3.0:installation; accepting-delivery

14.3 Accepting Delivery 

Check the delivery to make sure you have the right product, delivered in prime condition. Do not mix products, because different manufacturers use different paint formulations. Where different brands of pre-painted material are used on the same building, differences in colour, gloss, and weathering performance may appear clearly visible within a short time.

Ensure all components needed to complete the installation, including fasteners and accessories, are onsite before commencing installation.

14.3.1 Unloading 

Set out a flat area and supporting dunnage to ensure sheets will not be damaged by site debris.

When unloading by crane, ensure the lifting boom has a spreader bar and that tightening strops do not damage sheet laps. Slings or strops should be nylon with leather sleeves to prevent fraying or cutting and damaging slings. Single slings and chains should not be used to lift packs of cladding.

 

 

When unloading by hand, lift each sheet off the stack without sliding over under sheets, as that may cause damage to the paint.

The person receiving the roof is responsible for identifying a safe and convenient landing point for the load, in association with the main contractor. The mobile or truck mounted crane operator has the duty of declining any loading instruction which he deems unsafe.

Bundles or packs of roof cladding must remain banded when being lifted by a crane.
They must be placed adjacent to the portal frame and not mid-span on the purlins. Bundles must be placed so that their weight is spread over the entire area of the roof and should be positioned with the laps in the direction of laying.
Workers receiving a bundle of roof cladding on the roof must have sufficient mobility to avoid the load, and use tag lines to control the swinging of the load while it is out of reach.
Packs must be securely fixed to the structure, and part-packs must be re-fixed at the end of every day. 

14.3.2 Wet Storage Damage 

Close stacked sheets may deteriorate quickly if water enters the pack. This happens because the metal exposed to moisture without air forms bulky, unstable, and loosely adherent, hygroscopic compounds.

When wet sheets are delivered or they get wet in storage, they must be used immediately or dried. Sheets can be dried by filleting sheets or cross stacking them on a slope to allow water to drain and air to circulate between the sheets.

Only use a dry, well-ventilated environment for long term storage.

Failure to follow these handling and storage precautions could result in spoiling the surface appearance of the products and severely reducing their service life. On galvanised material this will appear as a white corrosion product (white rust); on Aluminium/Zinc steel the corrosion shows up black.

This should not be confused with fretting. On pre-painted steel, the result of wet storage damage could be a bubbling of the paint surface. Damage resulting from such failure invalidates the warranty.  See 4.11.7 Crevice Corrosion/Wet Storage Stain.

The extent and severity of wet storage stain is usually proportional to the length of time the sheeting has been wet. In the case of superficial attack, exposure to the atmosphere and careful cleaning will sufficiently reduce surface imperfections, but heavier deposits can damage the sheets enough that they require replacement.

Where it is likely that the roof or wall cladding will be stored on site for more than one week before installation, the contractor (or person responsible for doing ordering material) should consider including waterproof packaging from the manufacturer in the order.