How to paint a galvanized roof: choose and do it right
Most developers today cover the roof with painted corrugated board or metal tiles. But by the end of construction money is often not enough, so the choice of some falls on cheaper galvanized sheets.
A lot of roofs on houses of an older construction are made of them. To prolong their service life, and at the same time to change the color will help painting the galvanized roof with special compounds.
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What gives painting
Despite the galvanic resistance to corrosion and even the presence of a protective oil layer on the roofing sheets, after some time, under the influence of precipitation, it disappears and the metal begins to rust. Paint for galvanized roofs can prevent or stop this process, leading to the gradual destruction of the coating.
However, this is not the only reason for its use, there are others:
- This is an opportunity to change the appearance of the house.to create stylistically and coloristically verified harmony of the roof and facades;
- DIY roof painting will cost much less than a complete replacement of the roofing material, despite the high cost of formulations intended for this purpose.
But in order for the coating to reliably protect the surface from the aggressive effects of the atmosphere, make it more attractive and last more than one year, you need to know how to paint a galvanized roof and how to do it correctly.
Galvanizing compounds
Since the surface of galvanized metal has a high passivity, the paint for it should have good adhesive (adhesive) properties and elasticity.
Note. Oil-based paints and alkyd enamels, when applied to a metal, chemically interact with it, which leads to a significant deterioration in adhesion, and then a quick detachment from the surface. Therefore, their use is not recommended for this purpose, unless you want to repeat this labor-intensive and expensive procedure every year.
There are formulations based on synthetic acrylic resins specially developed for painting galvanized surfaces - acrylic primer-enamels. Their price is quite high, but it will also last for a long time, becoming not only an adornment of the old roof, but its reliable protection.
Which will lead to a significant increase in its life. There are many such compositions, we will consider the most high-quality and popular ones.
Silver silver
It is an anticorrosive enamel for ferrous and galvanized metal, produced on the basis of aluminum powder, which creates a barrier effect and increases the protective properties of the surface.
Also included:
- Perchlorovinyl resins;
- Epoxy resins;
- Anticorrosive additives;
- Organic solvents.
In addition to high resistance to corrosion, it gives the treated surface wear resistance and immunity to the effects of oils and petroleum products.
Hammerrayt
The products of this brand are famous for the fact that they do not require rust removal - paint can be applied directly on top of it.
It also has such positive qualities as:
- A variety of choice of color schemes;
- Quick drying;
- High adhesion to the metal surface;
- Creating a wear-resistant coating with increased anti-corrosion properties;
- Durability;
- Resistance to fading;
- High decorative properties.
However, a few years after application, rust can still come through the coating. Sometimes salt deposits and cracks form on it.
Tip. To avoid this, the roof surface must be well degreased before painting, and the paint should be applied not with a roller, but with a brush.
Tikkurila
The Finnish company Tіkkurila produces paints and varnishes literally for all types of work and for any surfaces. Paint for galvanized roofs has the same advantages as Hammerite compounds: it is easily distributed over the surface and dries quickly, forming a corrosion-resistant coating that reliably protects the roof from rainfall and retains its original color for many years.
But she also has additional advantages:
- It is resistant not only to precipitation, but also to aggressive chemical environments;
- It features high heat resistance (up to 80 degrees);
Tip. Tikkuril paint is even recommended to be applied in hot weather, since it adheres to hot galvanization better and more reliably.
- It also tolerates low temperatures. And not only during operation, but also during storage and transportation;
- It is applied in one coat, without requiring a preliminary primer of the surface.
Unique
Special uralkyd one-component enamel from the Russian company LKM Torg, which mainly produces special formulations. Like previous formulations, it contains anticorrosive additives and lightfast pigments.
Staining technology
Choosing a paint is only half the story. We also need a high-quality tool and clear instructions: how, what and in what sequence to do.
It is best to use a wide brush with a solid bristle that does not lose hair during operation. Or a spray gun (see How to choose a spray gun and not make a mistake).
As for the process itself, it is carried out in two stages.
Training
To understand what kind of preparatory work is required on the roof, you need to assess its condition, first cleaning the surface from debris and dirt. To do this, it is washed and washed with a solution of washing powder or other detergent, then rinsed with clean water from a hose.
- If the roof was painted earlier and the old paint peeled off, it must be cleaned;
- If there are rusted areas on it, they should be replaced or, if the damage is not critical, clean with kerosene or sanding.
Note. The last requirement applies only to paints that are not intended for application by rust.
- Holes from fasteners, cracks and other defects are sealed with sealant or soldering;
- The surface is then degreased to increase adhesion to the paint. And for some formulations it is recommended to apply a primer.
Specific recommendations are given by the manufacturer on the packaging, they must be carefully studied.
Dyeing
We turn to how to paint a galvanized roof:
- First, you need to choose a warm, dry day without a strong wind. Do not pull until the evening, as dew may fall on the freshly painted surface and spoil it.
- Secondly, after all the preparatory work, the roof must be allowed to dry. You should also wait for the drying of each coat of primer or paint if it is applied in several layers.
The work is performed by any convenient tool, moving from top to bottom and trying not to leave unpainted areas.
It is important! To avoid falls and injuries, you need to work with insurance.
Conclusion
As a rule, the paint holds on the surface for 8-10 years, after which the finish is repeated. But once every two or three years it is worth checking the condition of the coating and, if cracks and other damage have appeared on it, paint over these areas to prevent moisture from entering the metal.
The process itself is shown in more detail in the video in this article.
It’s better to use special paints every 8 years, even if they are more expensive than regular oil paints than every two years to climb the roof, risking to curl your neck. Oil paint begins to peel off already in the first year of painting.