On many buildings in the European countries, for example in Italy or England, you can see the copper roof with a noble green tint. This feature of copper shingles is called a patina effect. The patina appears after years of exploitation of the shingles or with a special technologies that used for it’s production.
The irreversible process of formation of copper patina on copper roof is time-consuming and depends on several factors, but the principle remains unchanged – golden “clean” copper at first tarnishes (3 months – half a year), and then turns into a light, and then to a dark brown “oxidized copper” (1-3 years), after that on a dark brown tiles gradually appears blue-green shades and finally a copper-green “patinated copper” roof becomes through 5-25 years.
Why such a range of terms?
You can often hear the words that the impact of the environment is destroying the roof. However, with the copper roof it is just the opposite. Rain, snow, sunlight and strong wind only contribute to the fact that the copper roofing sheets acquire a noble green shade. The more intense the aggressive influence of the elements, the more quickly copper roof becomes bright malachite color. And this color has for centuries regarded as one of the most beautiful for the roof.
Thus, in order to create the roof of patinated copper shingles, there are several ways. The first of them – to build or buy a house on the coast. Under the influence of salty winds and hot sun copper quickly turns green – just 3-5 years. If you live in an area with a temperate climate, you have to be patient. In such conditions, that copper become covered with patina may need 15 or maybe 20-25 years.
It is also important to note that the “natural” patina take place some negative aspects. For example, the uneven change in color of copper. This may especially be the case if the roof is a complex architectural design. In this case, its elements will be exposed to oxidation with varying intensity. Consequently, the roof will have different shades and colors.
But recently for impatient architects and customers there were technologies of “immediate” production of the patinated copper. It can be caused in the following ways:
- Copper sheets are treated with special chemical elements – acids, alkalis and so on. As a result, copper quickly covered with a layer of patina. The quality of the coating is the same as if the copper sheets for many years have been exposed to the environment.
- The second method – copper is placed in a special chamber. In it created the conditions in which the copper shingles naturally begins to be covered with a patina and acquires a bright green color. Unlike natural patina copper, using this method the green shade will be completely smooth. This is very important because the patina in the industrial environment is unique in terms of quality.
Both mentioned technologies are industrial secret of producers.
Sometimes attempts are made to an independent processing of copper roofing. Builders buy chemicals and applied them to copper right on the site where the construction takes place.
The results of such work are poor. Often copper becomes indefinite color with different shades. This can form spots, streaks, ie, the surface will become a non-uniform color. Such material can no longer be used to create high-quality and attractive roof. And to fix this kind of work is very difficult. You will have to buy a new batch of copper roofing and start all over again. So much easier, faster and cheaper to order a ready patina copper. You are in the short term get the required materials of the highest quality.