Liquid rubber V Lately is gaining increasing popularity as a material for roof waterproofing. Most often, liquid rubber is used to apply a coating to a flat surface. The use of liquid rubber on surfaces with a large area is one of the most convenient options, since when working with this material, it is very easy to apply a coating even to complex details of the roof topography.

What are the advantages of liquid rubber

It is worth noting that liquid rubber also has whole line undeniable advantages. These include, in particular:

• ease of application with high labor productivity;
• chemical resistance and environmental friendliness;
• Fire safety;
• reliable roof covering;
• high elasticity;
• no seams;
• resistance to various types of weather conditions and ultraviolet rays;
• complete protection from moisture;
• durability.

It is more convenient to use than roll and membrane coatings. Currently it is one of the most modern species roof waterproofing. Liquid rubber can be used both in the reconstruction of old buildings and in the construction of new construction projects. The most important advantage of this material is its versatility. The connection to the base occurs at the molecular level, due to which very high reliability of fastening is achieved, regardless of the texture or material of the roof.

However, to be fair, its shortcomings should also be pointed out. Firstly, the cost of liquid rubber is quite substantial. Secondly, it has a fairly high sensitivity to solvents and substances that include petroleum products. Thirdly, it will be possible to remove liquid rubber already applied to the surface, if such a need suddenly arises, only mechanically.

When covering the roof with liquid rubber, you should take into account the specific application of this material.

The most obvious way to see the coating of a roof with liquid rubber is when applying such a coating to roofs that have complex design stingray, or when working on large areas. The peculiarity of liquid rubber is its very wide scope of application, and this material can be applied even to an old coating: it only needs to be cleaned of debris.

Roof coating with liquid rubber is carried out in one of three ways:

• bulk;
• coloring;
• cold spraying.

However, regardless of which method is used, before starting work, you should thoroughly clean the base on which the liquid rubber coating will be applied. remember, that preparatory stage is very important, since the final result largely depends on it, so the old coating should be cleaned as much as possible of grainy coating and the exfoliated roofing material should be completely removed. You need to remove all the dirt, all the debris, and then get rid of the dust. Applying liquid rubber over old roofing material requires mandatory installation deflectors that pull moisture out of the roofing pie. Moreover, in some cases waterproofing layer It is recommended to reinforce it with geotextiles.

Let's move on to a more detailed look at how to apply a liquid rubber coating to a roof.

1. One of the ways to apply it is the pouring method. After clearing the surface of debris, you need to saturate the base with bitumen emulsion. The thickness of this layer (also called primer) should be from 1 to 2 millimeters. After this, liquid rubber is immediately applied to the base. It should be applied in certain portions, evenly distributed over the surface using special rollers.

The thickness of this layer should be from 2 to 3 millimeters. It should be noted that bitumen-latex mastic only needs a few seconds for it to begin to set, but in order for the job to be done efficiently, the applied layer should be allowed to sit for at least 5 minutes. After waiting the required time, you can begin applying the next layer - in most cases this is already finishing layer. The pouring method is used for flat surfaces, helping to level the roof itself as much as possible. For pitched roofs, the use of this option is, as a rule, not practiced.

1. The next step is to apply the base layer - at this stage the rubber mastic is no longer diluted with water. Using a spatula, apply the composition to the surface so that you end up with a layer 2 to 3 millimeters thick - a wide brush will also work for this work. The applied layer will dry completely after at least 48 hours. To ensure that the application of the second layer is as uniform as possible, it is recommended to apply it perpendicular to the direction in which you applied the primer - with this order of work, the liquid rubber will fully comply with all the declared characteristics. Note that this method is best suited for pitched roofs and small surfaces, when, from a financial point of view, it is simply unprofitable to use mechanical equipment.

1. And finally, the last method is the spraying method. As mentioned above, first of all, the base is carefully prepared, after which you can begin to directly treat the surface with liquid rubber by spraying. To do this, a special device should be connected to 2 containers. One of them contains a polymer-bitumen emulsion, the second contains calcium chloride, which acts as a hardener. Both of these components must be fed into the nozzle at the same time, they are mixed before spraying onto the surface.

Surface treatment with liquid rubber by spraying is in most cases used over large areas or on sloped roofs. The advantages of this method include, first of all, the speed of work and the quality of applying the rubber layer. The applied material hardens almost immediately, meaning there is no need to wait for the rubber to harden. In addition, the spraying method can be used on any surface. The material here is applied using a sprayer, which means that you can handle even the most bizarre designs without any problems.

IN last years Liquid rubber, or seamless insulation, is becoming increasingly popular for roof waterproofing work.

It is used to create waterproof, chemical, weather and heat resistant waterproofing coatings on the most different surfaces regardless geometric shape and inclination angle.

Roof waterproofing

Most often the material is used for flat surfaces. This is explained by the large area of ​​objects with a flat roof - up to several thousand square meters. Such scales significantly complicate the waterproofing process.

When using liquid rubber, the picture changes fundamentally: as the area to be treated increases, the work becomes easier, since this material easily covers even the most complex details of the roof topography: pipes, canopies, various parapets, protrusions.

The big advantage of liquid rubber is the possibility of better and faster implementation. necessary work than when using rolled waterproofing materials.

Types of roofing mastics, general characteristics of liquid rubber

Today, a huge variety of roofing mastics are produced. According to their composition they are divided into two main categories:

• one-component;
• multicomponent.

The first group includes materials that are arranged in the proportion required for application and further hardening.

Multicomponent mastic can be represented by several components. It must contain at least two ingredients: a base element and a curing catalyst.

Mastics consisting of two elements are called two-component. Liquid rubber is one of the types of materials in this group.

It should be noted that the name of the material does not convey its essence. This term is erroneous and was chosen for only one reason: it is the most convenient for consumers.

In appearance, this coating resembles rubber: it is black, has a viscous consistency, and is waterproof. The resemblance to rubber is limited external signs. The base of this material is not rubber, like rubber, but bitumen.

Israeli manufacturers - the creators of this substance - are categorically against the term “liquid rubber” and propose calling this type of coating seamless sprayed waterproofing. The offer is not accepted because the name is quite difficult for the average consumer: it causes confusion for most potential buyers. This is the reason for using the slightly incompetent but completely understandable designation “liquid rubber”.

By the way, a material of this type was created in the seventies in the USSR, but due to the low quality of the bitumen used, it was not widespread.

Technical properties of liquid rubber

Liquid rubber is a cold applied mastic. The basis of the substance is a water emulsion of polymer-bitumen type.

A distinctive feature of rubber is instant curing. Since it is produced on water based, then the evaporation of toxic substances is reduced to a minimum.

Waterproofing seamless coating“Liquid rubber” not only has a high degree of environmental safety, but also allows you to cope with construction work in the shortest possible time and provide a durable coating with a long service life.

Some types of mastic are applied by spraying. Thanks to this, joints and seams do not appear. Spraying makes it possible to use rubber for structures of any shape. Since the substance has low fluidity, it can be used to treat even vertically located surfaces.

The material does not deteriorate under the influence of ultraviolet irradiation and retains its qualities at elevated temperatures.

Depending on the used polymer additives, bitumen, specific brand and manufacturer, the lowest bending temperature on a beam can be 20 degrees. There are special types of liquid rubber developed for particularly cold regions (for example, Yakutia); they can be used at temperatures down to minus 60 degrees.

Since bitumen contains essential oils, over time they can evaporate. In this case, a special reaction is observed - bitumen aging effect. This process can be avoided thanks to the polymer contained in the mastic, which creates a film that prevents evaporation and prevents the aging of the bitumen contained in it. As a result, the service life of this coating is 20 years or more.

Liquid rubber is very elastic (its KPU is more than 1000%) and at the same time durable. Thanks to these qualities, it does not peel off even after sudden changes temperature, humidity level, pressure, surface vibration.

The membrane surface retains its properties even after complete hardening and does not lose them for a long time.

When using liquid rubber, you can do without further maintenance of the treated surface. If necessary, the material can be easily restored and repaired.

The created coating is resistant to mechanical stress, it is fireproof, and does not deteriorate under the influence of most materials used. construction work chemical substances.

Rubber combines perfectly with water-based (solvent-free) paints. This quality allows you to choose the color according to the customer’s wishes.

Types of liquid rubber

There are three types of liquid rubber:

• Bulk

– manufactured and formed right on the venue waterproofing works.

• Painting room

– installation of waterproofing is carried out by applying liquid and paste film-forming materials using conventional paint brushes, brushes and spatulas. The work is done manually.

• Sprayable

– application is carried out by cold spraying, using special equipment RX-27. This method It is distinguished by the ability to quickly complete all work and the high quality characteristics of the resulting coating.

Sprayed liquid rubber is classic version liquid material for carrying out waterproofing work, and it occupies one of the first positions among the materials used for waterproofing.

Features and benefits of the application process

When applying the substance to the surface to be treated, use a special spray bottle. The material hardens almost instantly. There is no need to preheat the surface, which means the process is completely fireproof.

Application by spraying allows you to use the substance sparingly and obtain a uniform layer. The thickness of the coating should be 2 mm.

When applying the layer, a special mobile dosing and mixing device is used on a gasoline engine weighing 68 kg. The equipment is very convenient to use, since there is no need for power supply. It can also be used in hard to reach places, since it is equipped with 150-meter hoses, allowing you to dispense with moving the entire device.

Liquid rubber has been tested for compliance with the safety regulations.

When working with material both in open and in indoors no need to use funds personal protection, since it is odorless and does not emit toxic substances.

Liquid rubber can be applied even to a damp surface, although it is still recommended to dry it first.

Applying mastic is a very easy and quick process. Thanks to its exceptional qualities, up to 2000 square meters can be processed. meters of surface per day.

Advantages of the material

Liquid rubber has a number of undeniable advantages:

• the material is stored in barrels in a liquid state;
• method of application - spraying by cold spraying - allows the substance to be used on a surface of any geometric shape;
• rubber has a high degree of adhesion to most building materials;
• When repairing a roof, liquid rubber can be sprayed directly onto the old waterproofing coating;
• after applying this material, even the most complex surfaces have no seams;
• material provides high level strength and elasticity of waterproofing;
• the roof becomes completely waterproof;
• after surface treatment, all holes and holes are closed;
• the substance does not corrode;
• it is completely safe from an environmental point of view;
• the material is very economical: for processing 1 sq. a meter takes approximately 1 to 3 kg of liquid rubber;
• when carrying out waterproofing work there is no need to use fire, electricity, or water;
• the coating created using liquid rubber has a high degree of resistance to temperature changes, very low and high temperatures;
• the material does not deteriorate under the influence of ultraviolet irradiation and chemicals;
• it has a long service life.

Flaws

Among the disadvantages of the material are the following:

• if necessary, the coating can only be removed mechanically;
• liquid rubber is highly sensitive to substances containing petroleum products and solvents;
• the price of the material is relatively high.

Areas of use

Liquid rubber can be used for application to the following materials:

• monolithic and prefabricated reinforced concrete;
• metal;
• cement strainer;
• slate;
• tree;
• roll materials;
• tiles.

Liquid rubber is more practical and easy to use compared to membrane and roll coverings thanks to the cold application method. It represents the most modern method surface protection. The material is used both in the construction of new facilities and during the repair and reconstruction of old buildings.

The main advantage of liquid rubber is its versatility: since its adhesion to the material occurs at the molecular level, it provides a strong hold on a material of any quality and texture.

When applying a coating to old waterproofing, the moisture accumulated during the period of use of the old coating is removed using special deflectors. If necessary, geotextile reinforcement of the coating can be carried out.
The use of liquid rubber is very convenient when processing surfaces with a large number of abutments. Materials for similar roofs roll type just useless. A high degree of vibration resistance makes it possible to use liquid rubber for roofs with ventilation outlets.

The material provides protection from vibration of the ventilation system, and it does not in any way affect the properties of the insulating material. In addition, rubber reliably isolates joints and junctions from moisture.

The low level of sensitivity to temperature changes makes it advisable to use this mastic in both very cold and extremely hot weather conditions.

Liquid rubber is used on all types of buildings: in the construction or repair of private houses, industrial facilities etc.

Thanks to your universal properties rubber is used not only as protective covering, but also as an independent roofing.

Sputtering technology

When applying liquid roofing rubber, as already mentioned, an airless two-channel dosing and mixing element is used.

Work must be carried out at a temperature of at least plus 5 degrees and dry weather. Rubber is best applied to a clean, dry surface, although it can also be sprayed onto a damp surface.

Before applying the material, the roof must be thoroughly washed using water washing machines operating under high pressure. After this, the surface must be dried. In the presence of greasy stains they must be disposed of by burning.

Before waterproofing begins, the following activities must be carried out:

• check the correctness and quality of the installation of the roofing base;
• prepare the roof base for further coating with a layer of liquid rubber;
• install the necessary equipment and tools in the work area;
• prepare the bitumen-polymer mixture for work.

Liquid rubber is applied to the roof in strips 1 to 1.5 meters wide. The layer should be uniform, with cross-shaped transitions. There should be no gaps on the roof surface. In areas where the roof is flat, a slip layer must be included. It is placed between protective layer and membrane. It is obtained by laying two layers, including geotextiles, fiberglass and polyethylene film.

Features of applying liquid rubber to a flat roof

Liquid rubber is often used for waterproofing flat roof. Features of the work are determined by the specific type of roof.

To obtain a waterproofing coating good quality, liquid rubber should be applied to a fairly smooth substrate. Perhaps the surface will not be perfectly flat - the main thing is the absence of extra items and significant defects.

Only under this condition, during spraying of the material, the layer is distributed evenly and turns out to be approximately the same height. The degree of smoothness of the created liquid roof depends on what device was used.

When a high-pressure unit is used and the surface to which the coating is applied is sufficiently smooth, a seamless membrane is obtained. In this case, the spraying method is used.

When using devices operating under low pressure, the likelihood of obtaining a smooth surface is low. Most likely, tubercles of different heights will appear on it, which will significantly spoil appearance roofs. If it is impossible to level the surface before spraying, it should be leveled using a screed.

When applying liquid rubber to roofing slabs, the amount of polymer-bitumen emulsion consumed may increase. If there is a primer layer, it is necessary, as far as possible, to reinforce all connections located in the spaces between the insulating boards. It is necessary to put strips of geotextile in them.

The best way to apply liquid rubber is to coat the already applied screed layer with the compound. In this case, it is guaranteed to receive flat surface and attractive appearance of the roof.

Prices

The cost of liquid roofing rubber is influenced by several factors, the main ones being the specific type of material, its quality characteristics, pricing policy of the manufacturer and seller.

You can navigate prices based on specific examples.

Liquid roofing rubber CBS for installation and waterproofing of roofs on concrete base, roof repair soft type from welded rolled materials and PVC membranes and recovery pitched roof based metal sheets, soft tiles and slate can be purchased for 97 rubles per kilogram.

ARCTIC roofing rubber CBS, which has increased frost resistance, is suitable for waterproofing roofs in Far North. Using this material, you can install and waterproof soft roofs on a concrete base, as well as waterproofing and repair work on roofs made of PVC membranes and fused rolled materials; repair and waterproofing of pitched roofs based on slate, metal sheets, soft roofing tiles. It can be purchased at a price of 108 rubles per kilogram.

Universal liquid rubber GI, used for waterproofing vertical and horizontal retaining walls on a concrete base, as well as for corrosion protection metal structures sells for 89 rubles per kilogram.

CONCLUSIONS

• Liquid rubber is a new word in construction. The material is used for waterproofing work.
• The substance is most often used on flat surfaces.
• The name does not correspond to its material composition, since the basis of liquid rubber is bitumen, not rubber.
• The main advantage of liquid rubber is the ability to use it on surfaces of any shape and any roofing material.
• Liquid rubber can be poured, painted or sprayed.
• The sprayed variety is applied using the cold spray method.
• When spraying, a special device is used.
• To obtain waterproofing High Quality The surface to be treated must be smooth, clean and dry.
• When applying liquid rubber, you must follow the instructions.
• Prices for liquid rubber depend on its type, technical characteristics and some other factors.

How the process of applying liquid rubber to the roof occurs can be seen in the video.

Good options roofing for baths - metal tiles, corrugated sheets and soft roofing. A soft roof is great for a bathhouse and, with proper and timely repairs, can last up to 50 years!

Repair soft roof needed much more often than restoration work on hard types of coatings. We recommend that you inspect the roofing carpet every year in the spring for defects and damage. Check not only finishing coat, but also drainage system, screed and hoods.

We will consider two repair methods:

Traditional repair method: fusing

To preserve the appearance and performance of the roof, the coating must be coated with a special mastic and covered with roofing felt every 3-4 years. Thanks to such an easy repair of a soft roof, the panels will be better protected from moisture and temperature changes.

You should start repairing soft roofs only in warm and dry weather. At the same time, the coating itself should not be wet - if it has recently rained, it is better to wait a couple of days.

The video shows the main steps:

Necessary materials for soft roof repair:

• Ruberoid or its analogues
• Gas torch or blowtorch
• Any bitumen mastic for waterproofing

Before repair work Carry out a thorough cleaning of the roof of the bathhouse, clean storm drains and receiving gutters.

Repair technology:

Damaged areas of the coating must be cut out and damaged areas of the screed removed as necessary.

Apply the coating in the direction from the top of the roof to the bottom. If it is necessary to install a patch, it is cut so that its size is 10 cm larger than the area being repaired. The patch is glued to any bitumen mastic.

Fill these areas with fresh solution and seal them using a primer containing rubber. Apply primer in two layers:

• the first layer - as an absorbent coating,
• then the second layer, which must be used to cover the damaged areas with a reserve.

Be sure to inspect and, if necessary, renew the roof parapets.

Rolled material is best fused using gas flame burner, application blowtorch not particularly effective. Slowly, from top to bottom, go over the entire area of ​​the bathhouse roof, fusing patches to the defective areas.

Final stage restoration work– processing of connections to dormer windows, parapets, air outlets, chimneys etc. This stage requires special attention.

Don't forget about weather vanes - devices that allow you to remove water vapor that has accumulated above the base of the roof. They are arranged in such a way that one device makes it possible to remove vapors from under the coating within a radius of approximately 8 meters.

It should be said that the main problems of bitumen roofing materials- this is the formation of cracks, as well as swelling (i.e. air bags) between their layers.

When is it produced? major renovation soft roof, cracks bend. If this area is located at the junction, first the protective metal apron is removed, then the damaged layer of material is cut out slightly above the crack.

After this, using the transition edge, free the roofing carpet from the bedding or protective layer. Do this to a width of up to one meter from the exposed side. Next, glue 2-3 layers of roofing material, extending it 10-15cm onto the main covering. Then replace the protective apron.

If you find air pockets between the layers of covering, remove the carpet from the bedding or protective material up to 20 cm wide from the swollen area. After this, use a sharp knife to make a cross-shaped cut across the air sac across its entire width and depth. Bend the edges of the cut, clean the swelling from debris, old bitumen mastic and if it is wet, dry it. Then apply any mastic, hot or cold, to the defective area, and glue the patch.

Then apply a final layer of bitumen on top of it and return the bent edges of the roofing to their places. Press them to the base, then cover the area to be treated with a patch a little bigger size than the previous one. At this point, the repair of a soft roof with your own hands can be considered complete.

Disadvantages of conventional repair methods:

Seasonal temperature fluctuations have the most negative impact on soft roof coverings. In this regard, the use of obsolete repair methods is not economically profitable and is far from rational.

When using them, financial resources for repairing soft roofs are spent alarmingly regularly. This happens on average once every 2 years and is often accompanied by local or complete replacement of the damaged coating. In addition, it is often necessary to reconstruct the roof frame due to the damaging effects of moisture.

Although bitumen is insoluble in water, it is completely or partially soluble in chloroform, benzene, carbon disulfide and other organic solvents. In other words - bitumen roofing does not have sufficient protection against aggressive chemicals.

Another important factor is that all types of bitumen are produced from fossil fuels. This leads to the following conclusion: using a burner when making repairs and installing soft roofs in summer time, can lead to fire.

Due to their physical properties bitumen is greatly deformed in winter, and many large and small cracks form. In hot summers, the material can leak, exposing the base of the roof. These problems allow precipitation to seep through damaged coatings, form air pockets, and accumulate moisture under the insulation.

Even if you use the latest rolled materials when repairing the soft roof of a garage, house, bathhouse, gluing their joints with bitumen heated by a burner will lead to the same result.

Repair of soft roofs using liquid rubber

Once you try to repair coatings using liquid rubber, you will forget about such work for a very long period - up to 15 years. This is possible due to the special properties of polymers.

The material can be used on flat and any pitched roofs. The use of liquid rubber is justified from any point of view:

• quality,
• durability,
• security,
• as well as financial benefits.

The composition used is, in fact, a two-component aqueous emulsion on a bitumen-polymer base. It must be applied using special equipment using cold spraying.

This absolutely eliminates the possibility of fires when carrying out roofing works and during subsequent operation of the coating. The composition does not contain toxic volatile compounds.

This method is suitable for both roof repairs made of soft tiles, and for roofing made of roll coverings.

It should be said about the high elasticity of the resulting coating. Its maximum elongation coefficient is more than 1000%. When you are repairing a soft roof, polymer material hardens almost instantly. This creates a durable rubber membrane that is resistant to both low and low temperatures. high temperatures. And the coating has the ability to “self-heal” and increased adhesion to the base.

Every roof needs some form of covering material, which serves as the front line of the building's defense against atmospheric influences. Therefore, the construction industry constantly offers new products on the coating market, and one of them is liquid roofing. Its operational properties and features will be discussed further.

Bitumen, as many years ago, is the basis for many roofing materials, especially for flat roofs, due to its specific chemical and physical properties.

New products are constantly being developed based on it, and one of them is liquid rubber. This is a bitumen-polymer containing one or more components.

Strictly speaking, “one-component” compositions can be called such only conditionally, since they represent ready-made mixtures various substances, ready for use and do not require mixing or other additional operations.

At the moment, liquid rubber for roofing is one of the most technologically advanced and easy-to-use materials.

It is used both independently and as waterproofing for other types of coatings - and, unlike classic films and membranes, it is applied over the base.

There are practically no roofs that cannot be coated with liquid roofing due to its high degree of adhesion (penetration and adhesion).

Among them:

• Monolithic and precast concrete
• Cement strainer
• Tree
• Metal
• Roof tiles (including as a bottom waterproofing layer)
• Slate
• Old coatings made from roll materials

At the same time, a special advantage of the material is that on the roof where liquid roofing is applied, the roof as such can be of any shape, and with the most complex geometry.

The advantages of this mastic include:

• Creating a continuous roofing carpet without seams
• No connection problems at the locations of various roof structures
• High elasticity
• Durability (20 years or more)
• Ease of application and fast drying
• High water resistance even in extreme conditions
• Chemical and biological resistance
• Wide operating temperature range (-60 - +110 °C)
• Environmental safety (can be used even indoors)
• Low material consumption (1-3 kg/m2)

The material can also be applied in almost any way:

• Brush
• Roller
• Spatula
• Rubber mop
• Spray installation

At the same time, high fire safety is ensured, since this roof is installed in a cold way, without the use of open fire.

Hardening occurs almost immediately after application. You can walk on the coating, and complete readiness occurs in a day.

Minimal preparation is required, similar to the installation of a conventional screed or surface painting: cleaning from dirt, degreasing, and, if necessary, a primer

Important information! Degreasing and priming work must not be carried out using substances based on petroleum products

A particularly effective area of ​​application for the material is roof repair with liquid rubber. As a rule, it is performed on the old coating made of rolled materials.

It is noteworthy that in this case, both when completely covering the old roofing carpet and when applying repair patches, removal of the old coating is required only in places where there is chipping. Even bubbles, after cutting them, can be filled with mastic.

Advice! In order to save money when installing a roof covering, you can use roll material as the main material, and use bitumen-polymer mastic to treat difficult areas - abutments, vertical and inclined surfaces, etc.

Of course, no material is without its drawbacks; liquid roofing also has them.

These include:

• Relatively high price
• Sensitivity to solvents and other petroleum-based products
• Possibility of removing the coating, if necessary, only mechanically

However, the advantages still outweigh: the speed of the device, the ability to apply to vertical surfaces(without subsequent sliding under the influence of heating by the sun's rays) - this material has no equal. Special mention should be made of high elasticity.

Thanks to it, when the temperature changes environment, even the most drastic - the roof will work together with the base, which will not allow damage to occur either in the covering itself or in the places where the carpet adjoins various elements roofs.

By installing additional protective layers (substrate underneath and hard covering - screed, cement tiles, etc.) on a material such as, for example, Ureplen, a liquid roof can be used.

Although mastic is usually produced in black, there are also colored options. It can also be tinted with silicone or water-based dyes.

The remarkable properties of liquid rubber (although in fact it is not rubber, it does not necessarily contain rubber) make it a universal and very practical coating.

And if you additionally coat it with protective paint against exposure to ultraviolet radiation, such a roof will last much longer than the 20 years stated in its characteristics.