Recommendation points
If you want the roofing to look the same after 10 years as immediately after installation, take care of its protection from contamination. will tell you about the list of tools that can prevent the growth of moss and mold, the settling and absorption of dust particles, the appearance of dirty streaks.
What coverage is out of the risk zone
Such characteristics as dirt resistance are taken into account by modern manufacturers of roofing coverings along with mechanical strength and corrosion resistance. As a rule, the struggle for a clean roof implies a decrease in adhesion so that dirt that has got on the surface is removed naturally: blown away by the wind or washed away by precipitation.
The most successful method of protection is considered to be covering the roof with a layer of weather-resistant polymer material. So, metal tiles, profiled sheets and folded roofs have a thin shell of polyurethane, plastisol, pural or special compounds with a somewhat classified recipe. It is difficult to keep dust on such a smooth surface, and thanks to antibacterial properties, in principle, it is impossible for the roof to become overgrown with moss or begin to mold.
The situation is completely different with mineral-based coatings. Due to their inherent porosity and roughness, they accumulate dirt, which means that the spores of microorganisms can retain moisture in themselves for a fairly long time, thus developing a nutrient medium for harmful flora. It is not possible to protect such minerals with a polymer shell. On the one hand, this is hindered by the very structure of the material, on the other hand, by the requirements for aesthetics and natural appearance..
Over time, on roofs made of slate, slate, flexible and natural tiles, an uneven color change appears, streaks and gray-marsh spots form. Removing them is not an easy task, because the more aggressive chemistry affects pollution, the greater the risk of the roofing material itself..
Even the polymer coating does not guarantee 100% purity. Bird droppings and rainwater in industrial regions are types of contaminants that stick well to any surface, leading to tarnishing of the originally beautiful material. Removing such plaque without damaging the thin protective layer is a task that requires a scrupulous approach. Fortunately, a whole range of both special chemicals and methods to prevent the formation of dirt and organic damage to the roof has been developed to keep the roof tidy..
Methods for removing contamination
Roof cleaning is usually done with a pressure washer. For this, almost any household units can be used: they are not able to develop too high a pressure that can harm the coating, but the cleaning efficiency and speed of operation may not be high enough. It is recommended to carry out hydrojet cleaning of the roof with installations capable of developing a pressure of at least 120-150 atmospheres.
When cleaning the roof, it is important to understand that the washed off dirt is a source of injury, because it is easy to slip on the flush products. Therefore, cleaning is carried out exclusively from the ridge downwards in strips of 50–100 cm. The most effective work of a car wash is achieved by holding the nozzle at a distance of 20–25 cm from the surface at an angle of 20–30 °. It is necessary to direct the stream exclusively from top to bottom, excluding the ingress of water under the horizontal joints of the coating.
Attention: cleaning of asbestos-cement sheets by a mechanical method can be performed only with abundant wetting, which excludes the spread of hazardous asbestos fibers.
Roof cleaning is a mandatory step before using anti-dirt products. However, not every household has a pressure washer, which is why chemicals for removing dirt have become very popular. As a rule, they are strong salt solutions containing highly effective surfactants. The brine kills organics while the surfactant prevents dissolved dirt from settling on clean roof areas. Before using cleaning chemicals, it is recommended to remove the main dirt mechanically in order to reduce the consumption of expensive products.
To date, the most effective means are:
AntiMousses Guard– a powerful antiseptic used not only for cleaning the roof, but in general to remove traces of organic contamination. The complex of fungicides that make up the composition lasts from 6 hours to a day, after which the contamination can be washed off without fear that the spores of microorganisms will get into the clean pores and harmful organic matter can develop again. Does not contain aggressive compounds that can harm mineral or polymer coatings.
Neomid 660– a domestic analogue of the above agent, a concentrated mixture of fungicides and herbicides, which is diluted with clean water before use in a ratio of 1: 4 to 1:10, depending on the degree of contamination. No need for subsequent rinsing: all dissolved dirt is washed off with rain water over time. But there are strict rules of application: it is forbidden to apply Neomid on a roof heated by the sun or in cases where it can rain in the next 24 hours after application.
Kerabit Bio Plus– a product that effectively removes organic pollution and prevents the further spread of green moss and lichens. The product is intended for use on bituminous tile roofs, however, it is well suited for any mineral coatings.
Working with roof cleaning chemicals requires precautions. Most of the substances are poisonous and their ingestion on the mucous membranes or in the respiratory tract can lead to serious consequences. When spraying products, be sure to use eye and respiratory protection. In addition, drugs should not be allowed to get on landscaping objects near the house, because herbicide additives kill any plant organics.
You can choose any cleaning compound available in your area, but there are a few rules to follow:
- The neutral acidity of the product. Alkalis and acids can irreversibly damage mineral and polymer coatings.
- Concentrated formula: depending on the thickness and degree of contamination in different parts of the roof, you have to change the strength of the solution.
- Presence of packing in small containers. On average, one roof may require 20-30 liters of the product. Before using the product in full, it is better to check its effectiveness in a separate area..
The latter does not mean that the market is flooded with fakes or poor quality cleaning compounds. The problem is that the species diversity of organic matter is high enough and there is no guarantee that in some regions the harmful flora will not be resistant to the preparations that make up the cleaning agent..
Preventive methods
Roof cleaning has only a temporary effect, especially for roofs that are close to tall or flowering trees, pigeon houses, and other potential sources of dirt. The greatest danger is posed by plant pollen, which provokes the development of mold and moss, while most other contaminants are washed off by rainwater..
There are a number of ways to prevent overgrowth in the future. The simplest one is to treat the roof with a fungicide at intervals of 2-3 years. You can use any cleaning agent from the list above at a concentration of 1: 5. Treatment should be carried out until the contamination is clearly visible, the task is to etch the spores from the pores of the material with the help of a fungicide.
Another way is to eliminate the porosity and hygroscopicity of the coating, and hence the conditions for the formation of a nutrient medium for microorganisms. This is especially true for washed mineral roofs. A jet of water under pressure washes away material particles, making the surface even more porous. In such cases, glazing the tiles or painting the slate allows you to restore the attractive appearance of the roof and extend the life of the coating by significantly slowing down the erosion processes..
There are several types of paints and varnishes suitable for application to the roof. The most budgetary ones are glyphtal and pentaphthalic enamels, which, when coated with slate, can have a service life of up to 10 years. Improved protective properties are characterized by rubber paints, which form a hydrophobic shell on the coating and give it bactericidal properties. The aesthetic properties are excellent: thanks to the rubber coating 3-5 times thicker than alkyd enamels, uniformity of color is guaranteed even on very large roof surfaces, while the matte finish makes the roof look attractive in any light.
The most advanced compositions make it possible to reproduce a protective layer of polymeric materials on the roof, which are used in the production of modern roofing coatings. We are talking about pural, plastisol, polyurethane – all compositions have a two-component formula and require careful compliance with the instructions for surface preparation and application technique.
However, there are roof coatings for which the above methods are irrelevant. For example, for bituminous shingles, the effects of both cleaning chemicals and water jet cleaning can be detrimental. Paint for shingles is also not an option: the consumption is too high, and there is no guarantee of reliable adhesion. In this case, a copper mesh nailed along the entire length of the ridge will help get rid of the main types of pollution – moss and lichen. Copper oxides dissolved in rainwater are toxic to harmful organics, while the effect is permanent, in contrast to chemical treatment.
Copper slats and nets to protect the roof from moss
Finally, we must not forget about the timely cleaning of the roof. Any type of coating must be clean, which reduces the likelihood and rate of damage by greenery, and also prevents uneven fading of the decorative coating in the sun.
How can I effectively protect my roof coverings from the growth of moss and accumulation of dirt? Any advice or recommended products for long-term maintenance?