AZ150 or AZ200. Which one is the one to use?
AZ roofing material is coated with 55% aluminium, 43.5% Zinc and 1.5% Silicon also referred to as 55% Aluminium-Zinc coating technology. The coating is available in either AZ150 or AZ200. This means that either each square meter is coated with at least 150gm/m2 or 200gm/m2. Why the difference? Well the higher the coating the more protection it offers. The performance of steel is affected by amongst others things uncontrollable factors in the environment. This includes not only atmospheric exposure and also service conditions due to the nature of activities within a facility. Marine exposure also has an impact on the sheeting. Exposure is usually broken in to the following categories, Rural, Light Industrial, Industrial/Coastal and Extreme Industrial/Coastal. The table below is a suggested guideline.
Be sure to select the correct product. To assist you ask your installer to provide you with a provisional warranty. This will allow you to know upfront the warranty period the steel mill is willing to offer and if you have selected the correct product. Upon receipt of your roof sheets always check the reverse side which will have a printed inscription showing the material and coating thickness. This way you are sure you are getting what you paid for.