SAISC TECHNICAL
Cladding:
Back to Basics
by BSi Steel
If one discusses cladding, I am quite certain that it would be up to individual interpretation what that actually means. Some may interpret it as flashings, some a material coating, some actual material with a coating. I have tried to cover all interpretations and kept the following information as simple and precise as possible to provide some insight into the meaning of“ cladding.” In essence cladding is the waterproof envelope of a building.
In the case of roofing it would either be a pierced fix or concealed fix profile produced a steel coated material in the desired profile( Corrugated, IBR, Widespan and / or a number of patented concealed fix designs).
The steel base material is most commonly protected by a galvanized( Z) or Aluminium- Zinc Coating( AZ) both of which offer different types of protection.
Galvanized coating The mild steel is continuously hot-dipped into an almost pure zinc formula to cover the material and this provides a sacrificial layer in the form of a shiny zinc coating, which can be supplied in various spangles to create a different surface appearance. As zinc has a corrosion rate one tenth that of steel a Z275 coating will protect the mild steel substrate for between 10 and 15 years, depending on environment.
Aluminum zinc coating The mild steel is continuously hot-dipped in a formulation of aluminum, zinc and silicon. The addition of aluminum increases the protection factor by almost 4 times in a marine environment thereby providing a tougher barrier between the mild steel substrate and the elements.
The above materials are available with an organic coating, in a range of colours, under various copyrighted names e. g. in the coated and painted mild steel substrates in the form of Chromadek( Mittal produced) and Colorplus( Safal produced). These coatings in addition to being aesthetically pleasing provide an additional barrier to corrosion.
Flashings The generic term for a number of specially formed designs which in broad terms are roofing components to seal the transition of areas of cladding( valleys, hips, ridges, barge, etc.) or where cladding joins masonry or decorative trim.
These flashings are produced from the above materials to ensure compliance and compatibility with the cladding materials to ensure the roof sheeting flows in design. It is advisable not to mix colour coated materials from different suppliers as each paint system has unique weathering characteristics.
Bullnosing and curving of roofing sheets is a process that is applied after the production of the profiled roof sheets and is a process rather than additional component as is the case in in Flashings.
BSi Steel( Pty) Ltd Roofing, is located at Kliprivier( Meyerton R59) and produce an IBR, Corrugated and Widespan Profiles in the mentioned materials. Bullnosing, curving and flashings are supplied to your specification.
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