Safintra gives some guidelines regarding best practice for on-site storage and installation of metal roofing.
The popularity of metal roofing and cladding is growing amongst built environment professionals who are looking for cutting-edge, sustainable and practical materials.
While the benefits of metal roofing and cladding include durability, reduced energy costs, increased service life and colour variety for aesthetics, a large percentage of customer complaints from both the residential and commercial/industrial sectors arise from issues due to incorrect installation.
It is therefore critical that every aspect of metal sheeting be considered, from selecting the material and the profile (pierced or concealed), through determining the insulation requirements, specifying appropriate fasteners and other accessories, and finally the installation.
Safintra advocates selecting an experienced, approved metal roofing installation partner, familiar with various metal roofing profiles, and whose installation experience can enhance the design, technical, structural and aesthetic vision and keep within the associated budgetary constraints of a building project.
Handling and storage
Concealed-fix metal roofing sheets are often rolled on-site and stored for later installation. ColurPlus®, ZincAL®, Aluminium and Rheinzink® are all premium quality materials and should be taken care of.
If roofing sheets are not kept dry during transit and storage, especially when they are stacked, moisture can collect between the sheets and cause significant damage, greatly reducing its service life. If a bundle gets wet, the sheeting needs to be separated and wiped with a clean cloth, and be allowed to dry thoroughly before installation.
When working with metal sheeting, installers must stay mindful of the risk of corrosion at all times, as different metals possess different physical and chemical properties resulting in varying degrees and rates at which they corrode.
If two dissimilar metals are placed together and water is present, an electrolytic circuit is created and one of the metals will start corroding, while the other will remain relatively protected or untouched. In turn, roofing products that are made of the same material are naturally compatible.
Before commencing installation, the contractor should verify that all items have been checked and accepted.
The small things
Even the most well planned and executed metal roofing solution can be undone by one simple component – a substandard fastener.
It is not always the wrong choice of fastener that causes failures – instead, the most common problem is products that do not meet the required standard. This is why it is imperative that roofing installers ensure that the correct class and type of fasteners and accessories are used to complement the service life of the roofing sheeting.
Safintra recommends that installers ask for technical assistance from their steel roofing manufacturer to prevent dissimilar metals being coupled, and to confirm the class of fasteners required to meet minimum standard requirements.
Concealed fix profiles such as Saflok® and Newlok™ fix to the purlin with a clip system that allows for natural thermal expansion and contraction of the roofing, and provide exceptional wind uplift strength.
Dust and water ponds
In unusually ribbed profiles, or in profiles not installed with the correct pitch, extended moisture periods can occur and ribs can prevent dust, sand and water from flowing away.
Researching the technical specifications of products in order to ascertain if the selected profile is correct for the specific application, will extend the life of the roof.
Keep it clean
Steel debris as a result from cutting or piercing steel roofing during installation, also called “swarf”, may include shavings or filings or pieces of other materials, which tends to embed itself into either the paint or metal coat of the roofing, making it very difficult to remove.
If it is left on the surface of the metal roof, these particles will cause rust stains that will detract from the finished appearance of a project. These stains are also often mistaken for early deterioration of the product.
Take care with sunscreen
In recent years it has been found that sunscreens containing semi-conducting metal oxides such as titanium oxide and zinc oxide will continue to damage the paint system on metal roofing materials in the presence of ultraviolet (UV) light and moisture.
Therefore it is recommended that installers wear clean, dry, cut-resistant gloves to prevent any sunscreen getting on the roof, bringing it in contact with titanium or zinc oxides.
Check the warranties
Safintra also recommends cleaning the surface of the roof regularly to ensure that material warranty conditions are met. There are some reputable organisations that can work with manufacturers to ensure that all is done in a matter befitting the warranty terms.
Tel: 011 323 6300
Safintra is a member of the Safal Group, one of the largest metal roofing companies on the African continent.
Seven branches in South Africa: Johannesburg, Durban, Cape Town, Nelspruit, Polokwane, Port Elizabeth and Bloemfontein.
Further operations: Namibia, Botswana, Mozambique, Malawi, Tanzania and East Africa.
Caption: Steel debris, also called “swarf”, may include shavings or filings or pieces of other materials, which tends to embed itself into either the paint or metal coat of the roofing, making it very difficult to remove. If it is left on the surface of the metal roof, these particles will cause rust stains.