How to get rid of moss on the roof: why it is harmful, why it appears, methods and means of control

Moss or lichen on the roof is a fairly common problem. They not only spoil the appearance of the house, but can also damage the coating. To prevent this from happening, you need to figure out how to get rid of moss on your roof.

Why does moss appear on the roof?

Moss reproduces by spores that can be easily carried by the wind and germinate on almost any surface. In garden plots it can often be seen not only on the roof, but also on a tree trunk, soil, fences, and paving slabs. Spores can germinate on any roof, regardless of the type of coating, especially if it has porous, rough structure of the material (various types of tiles, slate, rolled materials, polyester).

The condition for the germination of moss spores is an abundance of moisture and dust. Therefore, green areas often appear on the northwestern or northern side of the roof, shaded areas and where there is practically no direct sunlight.

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Spore germination can also be facilitated by:

• proximity of the house to a body of water (river, lake);
• the location of the house in a region where high air humidity prevails;
• roof contamination (accumulation of dirt, dry leaves or other debris on the surface that has not been removed for a long time;
• violations committed during the installation of the roof.

Dangers of Moss on the Roof

The debate about the dangers of green moss that may appear on the roof has been going on for a long time. Some consider it harmless, since it does not have a root system that can penetrate the surface of the roof covering and, accordingly, harm it. But that's not true. And you need to get rid of it as quickly as possible. The danger of this plant is as follows:

1. The structure of moss helps retain moisture inside it. Because of this, it becomes a good substrate for the reproduction of insects, other plants, and bacteria.
2. Overgrowth influences the transition from positive to negative temperature indicators in the cold season. This has a bad effect on some types of coverings, especially soft roofing, for which it is important to get rid of vegetation.
3. If there are a lot of plants on the roof, their weight begins to put pressure on the covering, which leads to disruption of the fastenings or their damage. They are also able to increase the gap that exists between the roofing elements. Because of this, leaks appear. A waterproofing film can protect against them. But in order to prevent the roof from leaking, you need to get rid of vegetation.
4. Vegetation can clog gutters, making it difficult for precipitation to drain properly from the roof.
5. Moss growths can thin the material. Therefore, over time, holes may appear in it, which reduce the reliability of the coating.

Physical and mechanical methods of controlling moss

The first signs of roof damage by lichens may appear 3-5 years after installation of the covering. It is easier to prevent the appearance of moss on the roof than to spend effort, time and money getting rid of it. You can prevent this problem by regularly cleaning the roof surface from leaves and debris, and especially carefully removing dirt from joints or crevices.

But, if vegetation has already appeared, you need to get rid of it. You need to start with mechanical cleaning of the surface. It happens:

1. Manual using water and hard brushes. They must be used carefully, especially on a soft roof. Work should begin by treating the surface with a dry brush, and then begin cleaning corners, holes, and crevices. If the work is carried out correctly, it will be possible to get rid of vegetation for 1-2 years.
2. Using a mini-wash. This method is more productive and requires less physical effort. Sinks are a device that generates a high-power stream of water. This allows you to completely get rid of vegetation and clean the roof without causing damage to it. For complete cleaning, professional high-pressure equipment is used. To prevent moisture from getting into the cracks between the ceilings and leading to the formation of mold, the water stream must be directed from above towards the bottom. This option will also allow you to get rid of the problem for 1-2 years.

The mechanical method of getting rid of moss is a temporary measure that is recommended every season. This will not only get rid of vegetation on the roof, but also prevent its reappearance.

If there is no desire or opportunity to carry out such a procedure every year, you can use a copper mesh or other copper devices. Copper saturates rainwater or other moisture with metal ions, preventing plants from growing on the roof.

Structural methods include installing a mesh attached to the surface of the roof, a copper brush or plates of this metal near the roof ridge. Despite the high cost and the need to buy copper nails for installation, this method of prevention is called one of the most effective.

Chemicals and herbicides that help get rid of moss on the roof

The definitive way to get rid of moss is with chemicals:

1. Chlorine bleach. The substance is mixed with water in a ratio of 1 to 10. Apply the solution with a spray bottle or soft sponge. It is important to use rubber gloves to protect the skin of your hands. You also need to wear a mask or respirator, as chlorine vapors can irritate the respiratory tract. If they are inhaled in large quantities, dizziness, headache, and general malaise may occur. When processing the roof, it is necessary to move from top to bottom. Chlorine-containing solutions should be used several times a year. It is better to do this in spring and autumn, when the air temperature is not higher than 15 and not lower than 5 degrees. It is important to ensure that the solution does not get into the drains, trees and plants growing around the building.
2. Roof antiseptics that help get rid of moss. Their selection is quite large. They differ in price and composition. Most of these solutions help get rid of lichens and protect the roof from plant germination for up to 3-4 years. They are applied similarly to chlorine-containing mixtures using a spray bottle or sponge. You also need to take care of the safety of the skin of your hands and respiratory organs.
3. Herbicides designed to control weeds, garden and vegetable plants. Such products have an aggressive composition. They are capable of completely destroying any vegetation, but when working with them you must adhere to safety precautions. During their application, particles of herbicides can get onto the surface of objects located in the yard, so they cannot be used for several days.
4. Antiseptic coatings. These are special impregnations that must be used during the installation of roofing materials. There are quite a lot of similar funds. When choosing, you should proceed from the type of coverage. However, such substances can ruin the appearance of the tiles, so first you should study the reviews of consumers of a particular product.
5. Protective silicone or varnish coatings. Their task is to make the surface smooth so that water flows down easily without lingering on the material. This will help prevent moss from appearing. But this option for roof protection is not suitable for every material, so before using them you need to consult a specialist.

Preventing the appearance of moss on the roof

In order not to have to clean the roof of moss and not to think about how to get rid of it, you should take measures to prevent its appearance and spread. You can protect your roof with:

1. Treating the roof with copper sulfate. Usually the procedure is carried out after mechanical cleaning of the coating. But preventive application of the solution will help prevent its occurrence. Thanks to spraying with the substance, the roof will be protected from the appearance of moss for a long time. The concentration of the solution is 350-500 mg of copper sulfate powder per 10 liters of water.
2. Applying saline solution. To prepare it, you need to take 1 kg of table salt, 2 kg of wood ash and 2 grated standard bars of laundry soap. All components are mixed with warm water to form a thin sour cream. The resulting mixture is treated with the roof surface. To avoid the appearance of moss, such treatment is carried out 1-2 times a year.

The appearance of moss on the roof can be dangerous, so it is necessary to get rid of such vegetation. Only in this case can you be sure that the coating will last as long as possible. It is worth remembering that this problem can be prevented even at the stage of laying the roofing material.

Have you ever encountered the appearance of moss on the roof of your house? Tell us in the comments how you were able to get rid of the problem, and bookmark the article so that you have the instructions at hand. Also share information with your friends who live in a country house on social networks, as this problem may also affect them.