At the Site Handling and Storage
To preserve the zinc/aluminium surface, handling should only be carried out using clean, dry gloves. Careless handling or excessive traffic on formed panels must be avoided as it causes unsightly scuffing and marking. Do not slide sheets over rough surfaces or over each other. As with zinc coated steel, packs of ZINCALUME® steel (in all finishes) must be kept dry in transit, stored clear of the ground and kept under cover to prevent water and/or condensation being trapped between adjacent surfaces.
To ensure the maximum protection against unsightly and damaging stains developing (if sheets become wet during storage), ZINCALUME® steel is chemically treated during processing to pacify the surface. If packs do become wet, sheets should be separated, wiped with a clean cloth without delay and placed so that air circulation completes the drying process. These procedures are recommended to avoid possible deterioration of the coating, leading to a reduced life expectancy or poor appearance.
Care and Storage
Care and storage of COLORBOND® steel prior to installation is vital to the life of the product when installed. If not required for immediate use, stack the sheets neatly and clear of the ground and provide cover to protect the sheeting from getting wet. A process called capillary action can cause corrosion which may lead to reduced life expectancy or a wet storage stain. Moisture on sheets or coil wraps of COLORBOND® steel can penetrate between surfaces causing temporary softening of the paint film and possibly even minor colour changes on some paint finishes. After drying, the coating will revert to its original state. Take extreme care with the surface until it has been dried and the coating hardness returns to normal.
Inert catchment has caused the demise of many a gutter. Roofing which does not change the quality or nature of rainwater as it flows across the roof is referred to as an inert catchment. Such roofing includes COLORBOND® steel, terracotta tiles, sealed concrete tiles, acrylic sheeting, glass, ZINCALUME® or aluminium.
This means that virtually pure water (plus any chlorides or acids dissolved in the rainwater from the atmosphere) flows into the gutter.
While galvanised steel gutters serve well for old fashioned roofs with unglazed tiles or galvanised steel sheeting, they are not serviceable for modern, inert roofing products.
Select COLORBOND® or ZINCALUME® steel for your gutters, as these will provide equal service to that of the roofing material. BlueScope Steel no longer recommends the use of galvanised rainwater products.
Fasteners and Accessories
The selection of the correct fasteners and accessories is crucial in ensuring the entire project enjoys maximum life. Fasteners used to fix roof sheeting must be chosen to last as long as the life of the ZINCALUME®/ COLORBOND® steel. In all cases they should comply with AS 3566:2002.
Rainwater goods and roof flashings should always be made from a material which is at least as durable as the roof sheeting. For example, a galvanised gutters with a COLORBOND® roof. See Section “Direct Contact Between Metals” for more information. Ask for ZINCALUME® or COLORBOND® steel by name.
COLORBOND® Ultra is ideal for severe marine and industrial environments. Both sides are treated with a high build corrosion resistant primer.
COLORBOND® is intended for a wide range of applications, and provides superb performance in moderate urban and rural environments.
There are certain adverse conditions in which ZINCALUME® and COLORBOND® steel are not suitable. They should not be used as walling buried in or touching soil or concrete, or as cladding for intensive animal shelters, concrete formwork or culverts.
Following this advice will give an installation which will avoid an early failure of one or more components.
Don’t forget to clean up each day. Swarf particles and other metal scraps, such as pop rivet stems and fasteners, if left on a ZINCALUME®/COLORBOND® steel surface, will cause rust stains which will detract from the finished appearance. Swarf should be swept or hosed from the job at the end of each day. Caution is needed when attempting to detach swarf which has become stuck. No action which is likely to remove the paint or metal coatings should be attempted. For critical applications, inspection of the job should be made after two weeks when rain or condensation will have caused any remaining swarf to rust, and will highlight affected areas.
Many COLORBOND® steel products are supplied with a specially designed polyethylene strippable film. This film protects the sheet during storage and handling and should be stripped off immediately on installation. Sunlight can increase the adhesion so it is vital that sheets are not left uncovered while outside. CORSTRIP® on coil should be removed within 12 months.
Lead flashings should not be used with ZINCALUME® steel. Soft zinc or aluminium should be used instead. See Section “Direct Contact Between Metals” for more information.
Neutral cure silicone rubber sealants are the only sealants recommended for use with COLORBOND® or ZINCALUME® steel. The advantages of neutral cure sealants are:
- They provide good adhesion and do not require
a primer except in extreme service conditions
- They resist extremes of both heat and cold while retaining good flexibility
- They provide high resistance to the damaging effects of ultra-violet rays
- They do not have acidic additives which may adversely affect steel. This gives long life compatible with ZINCALUME® and COLORBOND® steel
Sealants should be applied to avoid exposure to UV rays (i.e. sandwiched in the lap), so they don’t create water run-off and dirt tracks down a roof or facade.
To get the best possible performance from a ZINCALUME® or COLORBOND® steel product it is vital you treat it with care.
Areas not normally washed by rain need regular cleaning with water. These areas include the underside of carports and verandahs, soffits, wall cladding under eaves and the underside of eaves gutters. Washing should be done with clean water at least every six months or more frequently in coastal environments and areas with high levels of industrial fallout.
Maintenance must be frequent enough to ensure that accumulation of pollutants, salts, dust and other materials is minimised.
It is essential that special care is taken in cleaning bends, joints and formed parts of all products in unwashed areas. Night-time condensation combined with dust,
salts and pollutants can accelerate corrosion.
In cases where salts and dirts are not removed with regular washing down, a mild solution of detergent should be applied with a soft bristle brush, and then washed down with clean water. At no stage should solvent cleaners or hard bristle scrubbing brushes
In general ZINCALUME® and COLORBOND® products from Fielders® are not recommended to be used over or in close proximity to spa or swimming pool areas.
By undertaking preventative maintenance, the life span and performance of your Fielders® product will be significantly increased. For further information on correct maintenance techniques contact your local Fielders® representative.
Have you ever noticed how an otherwise professional job can be ruined by clumsy attempts to touch up minor damages such as scratches?
The use of spray cans result in not only coverage of the scratch but also of a considerable area surrounding it. The problem is not immediately obvious but the overspray paint weathers at a different rate to the oven dried paint on COLORBOND® steel and, eventually, you will be left with an unsightly blemish on the sheet. Our recommendation is not to touch up. Minor scratching will not affect the life of the sheet and is rarely obvious to a casual observer. Should damage be substantial the sheet should be replaced. Where touch up is required for pop rivets or fastener heads, touch up lacquer is available in 250ml tins and carries clear instructions for application.
Painting ZINCALUME® Steel
The smooth finish of ZINCALUME® steel provides excellent adhesive qualities for painting. It can be readily painted with a water-based acrylic top-coat (without priming) for a high quality finish.
Any specific details on paints or paint systems should be discussed with your paint supplier.
Handling Steel Roofing And Walling Products On Site
Appropriate safety precautions must always be taken when handling steel roofing and walling products on site.
Given the outdoor nature of roofing and walling erection it is recommended that suitable precautions be taken to prevent personal sun damage. It has been found that sunscreens containing semi-conducting metal oxides such as titanium dioxide (TiO2) and zinc oxide (ZnO) can accelerate the degradation of organic materials, including paint systems.
For personal safety, and to protect the surface of COLORBOND® steel prepainted steel, it is recommended to:
- Wear clean, dry, cut-resistant gloves that are suitable for the task.
- Take suitable protection against personal sun damage, and
- Prevent contact of the painted surface with titanium dioxide (TiO2) and zinc oxide (ZnO) containing sunscreens.