Standard gray slate does not attract attention at all with its appearance. However, by painting it in certain colors that match your exterior, you can radically change your opinion about this material. Slate paint must have certain properties, including, first of all, its resistance to moisture and color change. Let's look at how to choose the right paint for slate below.
Features and scope of use of slate
Slate is a fairly popular material for roofing. In addition, with its help it is possible to build fences for the site and even small outbuildings. Asbestos cement is used to make wave slate. With the help of special fibers, the mechanical resistance of slate is increased.
Slate sheets have a standard gray color. However, this material can be painted in almost any color or shade. This will improve not only its attractiveness, but also its performance characteristics.
In order to learn more about this material, we suggest that you familiarize yourself with its advantages and disadvantages. Let's start with the advantages:
- a successful combination of cement and asbestos significantly improves the strength of the slate covering;
- this roofing option heats up less from the sun than metal;
- the material is not susceptible to rust, has excellent moisture resistance and does not conduct electricity;
- during combustion the material does not emit toxic substances;
- slate has a long service life;
- the cost of such material is much lower than that of alternative roofing made of metal or corrugated sheets;
- slate is an excellent sound insulator - during heavy rain there is no noise inside the house.
Among the disadvantages of slate, we note:
- slate is quite fragile and can be easily damaged during transportation;
- The total weight of one sheet is about 18 kg, so at least two people will be required to lift it onto the roof.
When slate is exposed to moisture and temperature changes, it eventually begins to become covered with asbestos crumbs, resulting in the formation of microcracks and moss, which reduces its attractiveness.
In order to prevent this unpleasant factor, it is recommended to paint the slate. The paint will provide additional protection of the material from moisture, the formation of moss, and also increase the attractiveness of the appearance of the slate covering. Modern paints also contain antiseptic substances that prevent the development of mold and mildew. With their help, biological protection of the roofing is provided.
When planning to replace the old roof finish with a new slate one, we recommend that you first think about painting it. At the same time, it is recommended to carry out this work before installing slate on the roof.
Slate paint - features of choice and characteristics
In relation to the main active ingredient of slate paint, they are:
1. Acrylic or water-dispersion - this type of paint is applied to the slate surface previously coated with a primer. Acrylic paint for slate protects it from moisture and destruction, improves its sliding characteristics, thanks to which precipitation flows down the roof more easily. Acrylic-based paints dry quickly and come in a wide range of colors.
2. Paint for painting slate on an enamel basis - it is distinguished by a high content of binders in its composition, has moisture-proof properties, and is resistant to precipitation. The coating, after painting, acquires additional strength characteristics. The pigments contained in the paint protect the coating from fading.
3. Slate roofing paint in the form of liquid plastic is a synthetic material with a bitumen, polystyrene or polyvinyl chloride base. These paints are affordable, however, compared to acrylic paints, this material has lower moisture-proof properties. In addition, such paints often contain substances harmful to human health.
4. Rubber slate paint is a fairly popular material for painting roofs. Among the advantages of rubber-based paint, we note:
- high elasticity properties, when small cracks appear on the surface, the paint stretches without damage;
- the paint does not contain substances harmful to human health, it is non-flammable and has a high level of fire safety;
- provides slip protection, especially important when installing a flat roof;
- is highly resistant to wear and can last on the coating for many years;
- improves the performance qualities of slate - it is resistant to external irritants, fungus, corrosion and wetting;
- It is universal in use and has a varied color palette, so it will suit any exterior.
Using rubber paint to finish slate extends its service life several times. Slate becomes pleasant and attractive in texture. In addition, the paint perfectly waterproofs microcracks in slate. To ensure durability of the coating, it is recommended to apply rubber-based paint in at least two layers. It only takes a few hours for the paint to dry.
In relation to slate paint manufacturers, we note:
1. DachbeSchichtung - paint of German origin, has a high cost, which fully justifies its performance characteristics. The paint also has high adhesive properties, good strength, and long service life. However, this paint is suitable for coating natural tiles or slate.
2. Polyfarb - Polish dispersion-based paint, dries quickly and has a rich color palette. The paint has good resistance to moisture and ultraviolet radiation.
3. Aqua is a Finnish-Swedish paint that dissolves with water and is resistant to aggressive alkaline environments. It is used not only for painting the code, but also for applying it to a concrete base.
Tikurila paint for slate: features of use and characteristics
“Tikkulira” offers paint for slate “KILPI”. It is an acrylate-based coating, diluted with water, which allows you to paint not only slate, but also bitumen roofing or concrete tiles.
With the help of this paint it is possible to significantly extend the service life of slate. In addition, it is highly resistant to solar radiation, moisture and other atmospheric influences.
Acrylate-based paint reduces the impact of moisture on the slate covering, thanks to this, it is possible to maintain its original appearance for many years. The paint contains special components that prevent the development of mold and mildew. The coloring composition does not lose its elasticity at both high and low temperatures.
Using Tikkurila slate paint, you can create a beautiful matte finish that resists the accumulation of dirt and dust. There are many colors for painting slate that will harmoniously match any exterior.
Is slate painted with paint: features of applying rubber paint
Before you start coating slate with rubber paint, you should prepare the surface. If there is dirt, grease stains, or dust on the slate, they must be removed. Since slate is a porous surface, it is necessary to coat it with several layers of primer. Thus, it will be possible to reduce paint consumption.
Use white spirit to degrease the surface. If the slate has already been painted, try to remove the paint. To apply paint, the air temperature should be from 15 to 30 degrees Celsius. At the same time, the maximum humidity permissible for performing work is 75%.
Before starting work, read the instructions for use of the paint composition. Next, open the container and mix the paint. Please note that diluting paint with drying oil or any other thinner is unacceptable.
If the paint has a high viscosity, then it is possible to add superprimer 100 to it, and then in a very small amount. To mix the paint, use a drill with a mixing attachment or a construction mixer.
To apply paint to the slate surface, a roller or pneumatic spray is used, in which case the surface is covered in several layers. While working, stir the paint periodically.
Features of choosing paint for flat slate
When asking what paint to paint the slate on the roof with, you must first decide on the type of slate used to finish the roof. Most often it is wave or flat slate. The following types of coloring compositions are suitable for this or that option:
1. Acrylic-based paints are environmentally friendly, dry quickly, adhere well to the coating, and also help create a smooth surface. Using this material you can quickly and easily paint any type of slate. The main rule for the high-quality operation of such a coating is compliance with all conditions from the manufacturer for applying the coloring composition.
2. Bitumen paint compositions are less popular due to their toxicity, although they are affordable.
3. Liquid plastic forms a protective coating on the surface of the slate, which significantly improves the service life of the slate.
4. Among the main advantages of silicone-based paints, we note:
- absolute harmlessness;
- long-term operation;
- good adhesion with slate.
At the same time, such compositions are quite expensive and have high consumption.
5. Oil-based enamels are also used in the slate painting process. They do not lose color over many years of use, they have quite rich and bright shades, but they take a long time to dry, approximately 5 hours.
6. Silicone-based slate paint - consists of silicone with the addition of dyes and various types of flooring substances. The material is quite durable and resistant to mechanical substances.
It’s up to you to decide which slate paint is best, but remember that in the process of choosing paint, you need to take into account the individual characteristics of the work.
How to paint slate yourself
Before starting work, you should prepare the surface for painting. If the slate has not yet been laid on the roof, then paint it before performing installation work. If you do not follow the recommendations for preparing the surface for painting, the service life of the paint will be significantly reduced.
Before starting painting work, perform the following steps:
- thoroughly clean the roof for dirt; to remove moss, if present, use a stiff brush; carry out all work with extreme caution to avoid damaging the slate;
- check the roof for integrity; if there are cracks, they should be sealed using a special composition; to prepare it, combine PVA glue, cement, water and asbestos;
- remove dust from the surface of the roof, for these purposes you will need to use water and a brush; upon completion of work, the roof must be completely clean, and before painting you should wait until it dries;
- Next, the surface is treated with a primer, which will reduce the risk of fungus and mold spreading on it.
In addition, the use of a primer allows you to increase the level of adhesion between slate and paint, while reducing paint consumption. Otherwise, if you do not prime the slate, the paint will peel off after a while.
Try to carry out slate painting work in calm and dry weather, with the optimal air temperature being 22 degrees. The easiest way to apply paint to a surface is with a sprayer. However, when using a sprayer, the amount of paint increases slightly in consumption. Be sure to apply the composition in two or even three layers, first waiting for the previous one to dry.
All information on the drying time of the composition is in the instructions, so be sure to read it before starting work. The maximum strength of the coating will be achieved within a day or two after application of the paint. It is not recommended to paint slate using a roller, as it is inconvenient and takes a very long time. The roller is suitable exclusively for flat slate. At the same time, follow the safety rules for staying at heights. Wear non-slippery shoes and insurance.
Asbestos-cement slate roofs have been used in construction for decades, and slate is the most common roofing material in Russia. Asbestos cement is an artificial stone material obtained by hardening an aqueous mixture of Portland cement and finely fluffed chrysotile asbestos fibers that reinforce the cement component.
Asbestos-cement products have high mechanical strength in bending, low density, low thermal conductivity and water permeability, high frost resistance, resistance to alkalis, and are also characterized by sufficient biostability. Tensile strength of asbestos-cement slate sheet: in tension - 20...25 MPa, in bending - 27...42 MPa, in compression - 45 MPa or more.
Slate roof protection - slate treatment
The disadvantages of asbestos cement include: reduced strength when saturated with water, fragility and warping when humidity changes, poor impact resistance.
What and how can slate be processed? so that it does not turn green or black?
In order to get rid of these shortcomings, waterproof compounds are applied to the surface of asbestos-cement products, protecting the material from moisture and mechanical damage, ensuring good water drainage and not retaining dust.
To do this, the asbestos cement sheet is dried to 7...6% humidity, after which its surface is cleaned of dirt, primed and finally painted with weather- and water-resistant painting compounds.
By the way, to increase water resistance and reduce the release of asbestos dust, which causes specific diseases, the back side of the product is also primed.
Painting of slate sheets with perchlorovinyl compounds (PVC, TsPKhV, KhV-161) is carried out at a temperature not higher than +4°C (due to the toxicity of the compounds) and not lower than -20°C.
To do this, first apply perchlorovinyl primer to the surface of the sheet, which dries in 2–3 hours in summer conditions.
The dried surface is painted with perchlorovinyl compounds using a spray gun (preferably brand SO-71A). When using a mechanized painting method, the composition must be systematically mixed in the paint injection tank to avoid stratification. During operation, the distance from the gun to the surface to be painted must be at least 0.5 m; the gun should be moved along the surface evenly, at a speed of about 0.3 m/s.
Slate is painted in stripes. The first stripe is applied from top to bottom, the second to the right of the first, but from bottom to top, the third, like the first, and so on. To obtain a continuous coating (without gaps), it is necessary that each subsequent strip overlaps the previously applied one by 3...4 cm. Typically, two layers of the composition are applied to the slate, and the second layer is sprayed only after the first has dried.
When painting twice with a PVC composition, per 100 m² of surface the following is consumed (kg):
PVC paint - 59;
PVC primer - 15;
Solvent (solvent; R-4; 5% PVC varnish) - 10.
When applying a ready-to-use cement-perchlorovinyl composition (CPVC) to 100 m² of surface, 41 kg of the composition is consumed for the first painting, and 36 kg for the second.
Slate surfaces are also treated with KO-174 enamel, which is a dispersed system (suspension) consisting of a solid phase (fillers) and a liquid phase (organosilicon varnish KO-85, diluted with a solvent - a mixture of butyl acetate, acetone, xylene and toluene).
As a result of the evaporation of the solvent, the enamel hardens. The drying time of the enamel at a temperature of 18...25°C is about 2 hours. The enamel has good adhesion, so it reliably sticks to asbestos-cement sheets, and the enamel coating is characterized by high strength and water resistance.
Thickened enamel is diluted with R-5 thinner. Before painting with enamel, the surface is prepared in the same way as before painting it with perchlorovinyl compounds. The slate must be dried before painting, since its humidity should not exceed 8%.
Apply the enamel 2…3 times with a paint brush or paint sprayer. Each subsequent layer is applied 1…2 hours after the previous one. Please note that enamel is toxic, so it is used only for external use.
The slate is also covered with organo-silicate compounds. One of the most durable compositions is composition OS-12-03, which consists of the paint itself (a suspension of organosilicon polymers and inorganic additives in toluene) and a hardener - polybutyl titanate or butyl titanate.
Before use, add a hardener to the paint composition in an amount of 1% by weight of the paint and thoroughly mix the composition in the container for 1 hour using a nozzle with blades. The paint hardens as a result of a chemical reaction between the components. Xylene or toluene is used as a solvent. The coating has good adhesion and adheres reliably to concrete, cement, sand-lime brick, ceramics and metal (with the exception of halogen-containing plastics).
On slate and metal roofs, the organo-silicate composition is applied at temperatures from -40°C to +40°C, using a paint brush, roller or paint sprayer.
The composition dries quickly - in 30 minutes. The “viability” of the composition prepared for application is 24…48 hours. When applying a two-layer brush to asbestos-cement or concrete surfaces, up to 400 g of the composition per 1 m² is consumed. Of course, the composition is applied to the surface, previously cleaned of dust and lubricating oils, by spraying with mortar.
When working with a paint sprayer, use a nozzle with a diameter of 1.8...2 mm and form a round torch from the paint.
During the application of paint, it is thoroughly mixed by hand.
Slate asbestos-cement sheets are also painted with silicate paints prepared on the basis of potassium soluble glass (K2O mSiO2) with a density of 1.3...1.5 g/cm³. Silicate paints also contain a separately supplied mixture of pigments with chalk, taken in a 1:1 ratio (by weight).
The value m is the ratio of the number of silica molecules (SiO2) to the number of alkali oxide molecules (K2O) and is called the silicate module of glass. For potassium glass, m is 3…4. The higher the module, the higher the quality of liquid glass.
The density of glass depends on its concentration. Often liquid glass comes from the manufacturer with increased density, so it has to be diluted with water.
How to paint a slate roof: technology
The required amount of water is calculated by the formula:
U1=U2(p1-p2)/(p2-1000),
where U1 is the amount of water that needs to be added to the solution, l;
U2 - initial volume of liquid glass, l;
p1 and p2 - initial and required density of liquid glass according to the hydrometer, kg/m³.
There are 10 liters of liquid glass with a density of 1500 kg/m³. You need to get a solution with a density of 1370 kg/m³. It is required to determine the amount of water U1 that must be added to the solution. The amount of water added is:
U1=10*(1500-1370)/(1370-1000)=3.5 l.
Before use, strain the composition through a No. 0.25 mesh containing 694 holes/cm².
Silicate paints are made only with alkali-resistant pigments and they have fire-retardant properties. It is impossible to prepare the painting composition for future use, since after a day it becomes unsuitable for further use.
For silicate paints, it is allowed to use only potassium glass, since the presence of sodium glass (Na2O mSiO2) causes a white coating, so-called efflorescence, to appear on the painted surface.
Therefore, before using silicate paints, it is necessary to check their quality, that is, to determine whether they contain sodium soluble glass.
To do this, take a red clay brick, the five sides of which are painted twice with the paint tested twice. After the paint film has completely dried, the “experimental” brick is moistened with water until completely saturated and placed on the unpainted side. If the soluble glass contains an admixture of soda glass, then after 1…2 days a white coating will appear on the painted surfaces of the brick and the paint will begin to “chalk off” when rubbed by hand.
The slate surface is primed before painting with liquid glass with a density of 1.41 g/cm³, while the consumption of liquid potassium glass is 27.3 kg per 100 m².
The first painting is carried out with a composition with a density of 1.14 g/cm³, the second - 1.18 g/cm³. The consumption of liquid potassium glass (per 100 m²) for the first painting is 14.8 kg, for the second - 11.1 kg. Let's not forget about the dry pigment mixture, which will require 30.9 kg for the first coloring, and 26.6 kg for the second.
Asbestos-cement slate sheets are painted in warm weather (at positive temperatures), avoiding painting in direct sunlight.
To impart water-repellent properties to the applied film, hydrophobic additives - organosilicon liquids (GKZh-10 and GKZh-11) - are introduced into the silicate compositions intended for the second painting. They do it like this. Diluted liquid potassium glass (density 1.15 g/cm³) is loaded into the mixer, then the required amount of pigments is poured in and the components are mixed until homogeneous, where GKZh-10 or GKZh-11 (commercial 30% concentration) is added.
Consumption of hydrophobic additives is 2.3 kg per amount of liquid potassium glass required to cover 100 m² of slate.
Of the anhydrous compositions for painting asbestos-cement slate sheets, the following brands of paints are used:
White lead thickly ground (MA-011; MA-011-N-1; MA-011-N-2),
Thickly ground zinc white (MA-011; MA-011B; MA-011N; MA-011NV),
Oil paints (MA-011 and MA-015; thickly rubbed special),
Thickly rubbed oil and alkyd colored paints (MA-011; MA-015; GF-013; PF-014),
Oil and alkyd paints ready for use (MA-11; MANN; MA-15; MA-15N; GF-13; GF-13N; PF-14; PF-14N; MA-21; MA-21N; MA-22; MA-22N; MA-25;
Thickly grated lead greens (MA-011-N-2; MA-011-N-3; MA-015-N-2; MA-015-N-3),
Oil and alkyd paints, earthen, thickly rubbed (red lead, mummy, ocher).
All types of primers and the above-mentioned waterless paint compositions for external coatings are prepared only with natural drying oil and diluted only with natural drying oil!
Coloring is carried out in the manner described above. Before coating asbestos-cement slate surfaces with a protective composition, it is necessary to carry out preparatory work to clean them from dust and soot, dry and prime the slate.
I repeat, it is not allowed to paint in dry and hot weather, when exposed to direct sunlight, as well as during rain or on a damp surface, and you should not work in strong winds.
The most favorable time of year for painting asbestos-cement roofing is the spring months. Painting work is carried out using special ladders that evenly distribute a person’s weight over the surface of asbestos-cement slate surfaces, which prevents damage to them.
All materials from the “Repair and Construction” section
How to paint slate?
1.Characteristics of slate as a roofing covering
2. Slate roof repair
3. Cleaning the roof
4. Elimination of cracks and replacement of sheets
5. Painting slate
Roofing material such as slate is always popular, regardless of the appearance of new coatings on the market.
It is distinguished not only by its reliability, but also by its affordability. Slate painting is done in order to increase the service life of this roofing coating. Therefore, it is worth understanding how to paint slate and how to paint slate on the roof, as well as how to repair the roof. Detailed instructions with photos and videos of this process can be easily found on our website if desired.
Characteristics of slate as a roofing covering
This material, which was once made using shale, is one of the oldest materials of its kind. Of course, such natural slate slate is quite difficult to find today, partly due to the fact that it has an incredibly high price (read: “Installation of slate roofing - installation methods”).
However, an artificial version of such a coating - flat or corrugated asbestos-cement sheets - are very widespread today.
Nowadays, other roofing materials are offered that have some relation to slate, for example, Euro-slate, the basis of which is bitumen (read: “Euro-slate - reviews and main characteristics”), metal slate, etc.
But asbestos-cement slate is still the most popular roofing type.
The main advantages of slate:
- a do-it-yourself slate roof is easy to make;
- low level of thermal conductivity;
- resistance to low temperatures and atmospheric conditions;
- affordability;
- fire safety.
Slate roofing is, by definition, durable.
This is especially true for roofs where painted slate is used, since the protective film created by slate paint helps to increase the slate’s resistance to various mechanical and natural influences, therefore, the service life of the roof is extended.
In addition, slate is a completely repairable material. So, if any cracks or defects appear on the slate sheets, then there is absolutely no need to redo the entire roof, even if a significant part of the material is completely destroyed.
It will only be enough to replace the damaged sheets, taking into account the size of the slate that was previously used.
What and how to paint flat slate? Overview of market offers + step-by-step instructions
In the case when painted slate is used, there is absolutely no danger to health, since thanks to paint it not only increases the reliability of the roof, but also stops the emission of dust, which contains asbestos particles.
Slate roof repair
No matter how mobile and easy to repair slate is, if any defects appear, repairs still need to be done, and the sooner the better.
Typically repair work consists of three stages:
- roof cleaning;
- elimination of cracks or, if necessary, replacement of sheets;
- painting slate.
Repairing a slate roof with your own hands and strictly following the rules of all three stages will allow the roof to last for decades.
Roof cleaning
Usually, if the roofing material is painted slate, then cleaning the roof will not present any difficulty; you will only need to sweep away all the debris that has accumulated on it.
If the slate sheets are not painted, this can lead to the appearance of moss and lichen on them, which, of course, cannot have a positive effect on both the appearance of the roof and its performance properties.
One of the tools used to clean the roof is a brush equipped with metal bristles. The work can be simplified by using a drill with an attachment similar to a wire brush.
Ordinary water supplied under pressure can also clean slate well.
Compact portable car washes used for cars are perfect here.
Repairing cracks and replacing sheets
The basis for repairing relatively small cracks in slate can be mastic, the base of which is bitumen or a special putty made using chalk and drying oil.
A special composition for repairing cracks may also consist of the following elements:
- 2 cement parts;
- 3 asbestos parts;
- PVA glue diluted in a 1/1 ratio with water or undiluted frost-resistant water-based paint.
Liquid elements must be selected in such a volume that the final composition has the consistency of a thick paste.
Due to rapid hardening, these compositions need to be prepared in small portions.
Another option for sealing wide cracks is to glue patches made of fabric onto them.
In this case, the desired area is primed, and then a patch is applied to a thick layer of paint, the size of which should be 10 centimeters larger than the size of the crack. Next, the patch needs to be covered with an additional layer of paint.
This same stage of repair also includes the replacement of damaged slate sheets. To do this, special walkways are mounted on both sides of such a sheet, for which ridge brackets serve as fastenings. To move on the roof during repairs, in this case, a wide board is placed across these walkways, on which you can walk if necessary.
The nails and screws on the required sheets must either be completely removed or loosened. If nails are being removed with a nail puller, it is important to place a piece of wood underneath the tool.
The required sheet, that is, the one that needs to be replaced, needs to be lifted and a new one placed in its place. It should be located along the edge of the ceiling and move towards the ridge. The new installed sheet is secured with screws or nails.
Slate painting
All professionals agree that painting slate is not only possible, but necessary, as this significantly improves the properties of the roof and extends its service life.
An important factor is the aesthetic appearance of the painted roof.
Therefore, painting slate with your own hands can be done; a more difficult question will be how to paint flat slate. Previously, standard oil paint was used for this, despite all the negative nuances of this method (fragility, tendency to rapid destruction).
Nowadays, special paint and varnish compositions are becoming increasingly widespread, which are suitable for painting not only slate, but also tiles, concrete, etc. The basis of such paints is acrylic, thanks to which these compositions are resistant to low temperatures, solar radiation and precipitation.
This, of course, has a positive effect on the aesthetic appearance of the roof, which will remain so for a long time.
When deciding what to paint slate with, you can choose a special paint for slate, called triora. It is resistant to external influences, in addition, it can be used both for slate and tiles, and even to cover the basement of a building.
There are other paints produced by both domestic and foreign manufacturers (read: “How to paint a slate roof: technology”).
Painting slate yourself, that is, without the participation of professionals, is quite possible. Of course, the best option would be to paint the slate sheets before laying them, but this will not be possible during repairs, so you will need to apply paint to already laid sheets.
3 stages of slate painting:
- primer is applied;
- the main coating is applied;
- The final coating is applied.
The painting tool can be a spray gun or a paint brush.
Flat slate can also be painted using a roller; the size of the flat slate allows this.
Before applying primer to the slate, it is best to properly treat the coating with an antiseptic solution, which is most often sold in concentrated form and is diluted with water before use.
Using such a solution will prevent fungus or lichen from appearing on the slate. It can be applied either with a wide brush or with any device capable of spraying liquid. It is important to remember about protective equipment - glasses, gloves, a respirator.
A slate primer can then be applied, which often contains acrylic liquid compounds that can penetrate deep into the pores of the coating, thereby giving it greater durability and better adhesion of the slate to the paint.
Painting slate on the roof, watch the video:
Very often, primer from one or another manufacturer is offered along with paint, so it would be better to opt for the same brand. Apply primer in the same way as paint: you can do it with a sprayer or a roller.
Due to the fact that slate is a porous material, painting it without a primer will be uneven, which will certainly lead to excessive paint consumption.
After the primer has dried, you can begin to apply the main coat of paint. It is very important to apply it well to all corners and ends of the coating.
The final coating is designed to give slate roofing a beautiful appearance.
It helps to make the surface uniform and uniform, without visual transitions and paint streaks. This layer can be applied only after the base layer has dried.
The paint used for the final coating is the same as for the main one, the only difference is in its smaller quantity.
The last stage requires approximately one third of the total paint volume, and the base coat - two thirds.
So, it is quite possible to paint slate yourself. This will provide an excellent opportunity to save a significant amount of money, since the services of professional craftsmen are usually not very cheap.
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Many people want to update the look of the roof of their home. Thanks to modern technology, this is not so difficult. The most common procedure – painting with special compounds – allows you to transform the dull appearance of gray asbestos cement sheets into a bright, beautiful and unusual one.
For a long time, slate was a completely self-sufficient roofing material that has proven its reliability for decades. However, if you remember its unattractive gray color, then the question of whether it can be painted has not lost its relevance all this time. Decoration is just one aspect.
Painting solves purely protective problems in practice. Paint protects the roof surface from destructive atmospheric influences; it helps reduce water absorption and increase frost resistance. That is, it can be argued that depending on what paint you use to paint the slate, you can significantly increase the service life of the asbestos-cement roof.
Is it possible to paint and with what?
You can often hear that paint for flat slate is very short-lived - one winter is enough and it will crumble. Undoubtedly, this cannot be ruled out, but only for those cases when it is chosen incorrectly. Let's try to figure out what and what paint is best to paint with.
Types of paint
Typically, asbestos is painted with one of the following materials:
- containing acrylic;
- quick-drying;
- liquid plastic.
The last of them is perhaps the least suitable for asbestos-cement roofing. Unlike the other two, it is less weather-resistant, and also has a rather pungent, unpleasant odor.
Enamel with a quick-drying composition gives the roof an exceptional decorative effect. This finish is resistant to weather conditions and UV radiation. The consumption of this material is 100–150 g per square meter. m. The performance characteristics of the coating are maintained for 3–5 years.
It is no coincidence that acrylic compounds are used predominantly for painting ACL. It is considered the most durable and safe of the above. After applying the composition, a moisture-proof film is formed on the roof surface, which, if properly applied, does not collapse for at least ten years. Acrylic coatings create a smooth surface along which rain and melt water flows freely and snow melts off, reducing the load on the supporting structure of the roof.
The latter is very important, given the significant load from the asbestos-cement sheets themselves.
It takes more acrylic than a quick-drying composition to cover a unit area - about 0.3 kg per square meter. m. Acrylic compositions
- environmentally friendly,
- do not have harmful secretions,
- wear-resistant,
- dry quickly,
- provide increased adhesion.
- completely fill all cracks, and the resulting sufficiently strong layer effectively protects the material from destruction.
When applying paint to the roof, you must strictly adhere to the manufacturer's recommendations - they are usually marked on the packaging.
The list of materials is much wider.
- Bitumen compositions are moisture- and frost-resistant and have an affordable price. However, they are toxic, wear out easily, are not aesthetically pleasing, and require a long time to dry.
- Silicone compounds extend the service life of the roof, are non-toxic, resistant to atmospheric influences, but are quite expensive and this comes with significant paint consumption.
- Special oil enamels are distinguished by a wide variety of shades and durability. They take quite a long time to dry, about six hours, and their service life is about three years, which is undoubtedly not very long.
- Organosilicon paint is a mixture of dyes and fillers. The basic component of this composition is silicone. This is a durable material that is resistant to mechanical stress. Such a protective layer prevents the release of asbestos particles into the atmosphere. Such compositions are only suitable for this type of coating and require careful treatment of the base using a silicone primer. To give greater durability, the paint is applied in at least two layers.
Stages of painting an asbestos cement roof
Before painting the coating, quite labor-intensive preparation is carried out. First of all, each of the sheets is checked for integrity and reliability of their fixation.
Sheets that show cracks or damage must be replaced.
The next step is to carefully clean the roof of any dirt, moss, etc. Asbestos-cement sheets are cleaned of old plaque using sandpaper and treated with an acrylic primer containing a special antifungal component. As a result of the primer, the pores of the roofing material are filled.
After the primer has dried, cement mortar is applied to the asbestos-cement sheets. The consistency should resemble kefir. A brush is used to apply the solution. Other tools, say a roller, are not suitable for this.
After allowing the cement mixture to dry completely, the roof is primed, after which the roof is painted.
When is the best time to do the work?
Is it possible to paint in wet weather, when is the best time to paint? Questions that concern many, especially those who intend to handle the roof themselves. Painting of ACL must be carried out in the dry, warm season.
The paint is applied in two layers using ordinary painting tools, for example, a spray gun. The second layer is applied to the completely dry first one. Practical experience shows that painting in the spring provides them with long-lasting protection, gives the roof a decorative appearance, and prevents the appearance of moss.
For any home, the roof is an important element that protects it from the effects of wind and precipitation. No less important functions are also thermal protection and making the appearance of the building attractive. From a huge list of widely used roofing materials, many consumers choose ordinary asbestos-cement corrugated slate. They make their choice thanks to the many advantages of this material.
- Cheaper than other roofing materials.
- Durability.
- High strength allows you to withstand the weight of a person during installation, as well as the weight of snow cover.
- Low noise.
- Not flammable.
- It is not subject to corrosion and is a good insulator.
- Does not heat up much in sunny weather.
- Excellent processing with mechanical tools.
- Slate roofing can be easily repaired by replacing damaged sheets.
In addition to its advantages, slate has the following disadvantages:
- It is a rather heavy building material that requires significant physical effort during its installation.
- A very fragile material that requires careful handling during transportation and installation.
- Over time it may become covered with moss.
- It contains asbestos, a substance harmful to human health.
To eliminate the last two shortcomings, you can paint slate sheets using special paints. To carry out this work, it is advisable to involve professionals from a specialized company. But if you have the necessary skills and free time, then painting slate yourself will allow you to reduce costs.
The article outlines the main points associated with painting slate.
Preparatory work
Of course, the easiest way is to paint new slate, even before laying it. In this case, you will not need to do additional work before painting: using a scraper or stiff brush to clean the old slate from dirt, moss and lichens. Please note that to obtain a high-quality result, these works should be performed in dry weather.
To prevent the growth of fungi and the formation of lichen, it is necessary to treat the surface of the slate with an antiseptic. Application of the composition can be done using a wide brush or spray, taking all necessary safety precautions (use a respirator, gloves and goggles).
Video
Surface priming
It is performed after the antiseptic layer has dried. Due to the deep penetration of the primer into the pores of the slate, its surface is strengthened and excellent adhesion to the slate is ensured by the applied layer of paint. The primer should be applied by roller or spray. For best results, use a primer from the same manufacturer as the paint. You should not refuse to use a primer, because... Without it, due to the high porosity of slate, despite the increase in paint consumption, you will not be able to achieve uniform painting of the entire surface.
Slate painting
After the primer has dried, you can begin applying the so-called first coat of paint. It is considered basic, basic. You should carefully paint all the ends of the slate covering, hard-to-reach places and corners.
To obtain a uniformly painted surface and avoid the formation of streaks and transitions, the same paint must be applied to the completely dry base layer as a topcoat.
About two-thirds of the amount of paint and varnish material is spent on creating the base coat (one-third is spent on creating the finishing layer).
To obtain a durable coating, you should use special acrylic paint, and painting work should be done in the summer, in dry, but not very hot weather.
Video
This is how slate is painted using a sprayer:
How and with what to paint a slate roof
More recently, slate was so popular that two-thirds of buildings in our country were covered with it. Currently, in conditions of constant competition, each manufacturer is trying to improve the quality and diversify the roofing materials they produce. Despite this, slate is still in demand, and all thanks to its positive aspects, which have remained unchanged over time. This is a low price, good water and frost resistance, and a long service life. But these qualities are not always the main ones when choosing a material for the roof, especially considering that over time slate acquires a gray-green color, especially on the north side, which is often covered with moss. And just new factory slate will not add any zest to the new home.
Recently, such types of slate have been used as profiled sheets, flat slabs and roofing panels.
If you still choose slate, there is one option that will help decorate the appearance of the house, namely painting the slate.
Preparing slate for painting
To paint slate, you need to prepare the following materials and tools:
- metal brush;
- drill;
- Bulgarian;
- high pressure jet washer;
- construction antiseptic;
- brush;
- spray;
- respirator;
- glasses;
- gloves;
- acrylic or enamel paint;
- primer.
Before you start painting, you need to clean the slate. especially if it has been in use for several years.
A slate roof can be cleaned in a variety of ways.
A regular metal brush is suitable for cleaning slate, but it is better to use a steam unit.
The first is to clean it yourself using a regular metal brush. This method is the most labor-intensive and time-consuming, but the efficiency and quality leave much to be desired. The main requirement when performing this work is that the roof is not wet.
The second method is to clean the roof using a special attachment on a drill or grinder. Cleaning the roof in this way has only one advantage - it is quality due to the use of power tools. This does not reduce the cleaning speed.
The third method is the most effective, and most importantly, it allows you not to stop working due to weather conditions. Its essence lies in the fact that slate is cleaned with water under high pressure. In order to clean the roof this way, you will need a specialized washer to create a high-pressure jet. The optimal pressure for such a process should not exceed 250 atmospheres. This is due to the fact that an increase in pressure above the norm can damage the slate itself, and a jet with low pressure levels will not allow the surface to be properly cleaned.
The undoubted advantage of this method is that it will take only 1-2 days to clean a roof with an area of 100 m2.
Treatment of slate before painting
The next step in preparing slate for painting on your own is treating it with an antiseptic followed by hydrophobization.
As you know, fungal spores multiply in a damp environment, so the slate needs to be treated with a product to increase water repellency.
The result of cleaning the slate: not a trace of debris, mold or fungi remained.
It is also important that old slate has increased porosity and is therefore susceptible to premature destruction in conditions of high humidity. Hydrophobization is used to prevent this and to increase the service life of slate.
To give the treated roof an aesthetic appearance, they resort to painting it. Of course, ideally, painting the roof (slate) is carried out immediately before the start of roofing work. But, as a rule, it is after several years that the owners only begin to think about what to do with the terrible roof and how to paint the slate that is already lying there. In turn, the stage of painting the roof is the most important and final.
Sometimes the average person may wonder whether slate can be painted. The answer is simple: not only is it possible, but it is also necessary. Paint is an additional protective layer that will strengthen the slate structure from destruction. Painted slate is less susceptible to severe frost.
Choosing paint for slate
Paint on slate is easily applied with a regular brush.
Correctly chosen paint is the key to not only the beauty of the future roof, but also high-quality protection. Nowadays, slate paints are presented in acrylic and enamel samples.
Experts recommend using these types of paints for painting, since they are designed to close all microcracks on the slate, and the film formed as a result of painting will cope perfectly with atmospheric phenomena. These paints contain binding components, making them ideal for painting flat slate. In cases where the roof is used in extreme weather conditions, with different ambient temperatures, it is best to use quick-drying enamels.
And yet, when you need to choose what to paint slate with, it is recommended to turn to specialists. They will always help you choose the right paint, taking into account the actual condition of the roof.
The quality of painting is influenced not only by correctly selected paint, but also by the technology of the application process itself. Basically this process can be broken down into three stages:
Instead of a brush, you can use a special paint sprayer - this will significantly speed up the process of updating the roof.
- Coating the slate surface with a primer.
- Painting the slate with the first coat of paint.
- Applying the second (finishing) coat of paint.
For priming, it is better to use compounds with deep penetration, which will ensure significant strengthening of the slate surface. It is much easier to paint a pre-primed roof, since, thanks to the primer, the paint will apply more evenly, and its consumption will be significantly less than without pre-treatment. The recommended primer consumption is 100-150 g per slate sheet. It is best to apply the primer with a sprayer, at an air temperature ranging from +5 to +30 degrees. Complete drying time is about 12 hours. After this time has passed, you can only begin to paint. It is not recommended to work with soil solutions with unprotected hands; you should avoid getting them in your eyes. Properly preparing the slate surface before painting is the guarantee that the paint will last for many years and will not have to be repainted.
After applying the primer, you need to let the roof dry for a day, and the next day you can start painting it.
Slate painting technology
When starting to paint slate with the first layer, you need to take into account the fact that it is the main one and 2/3 of all paints and varnishes are consumed on it. The slate sheet painted with the first layer should not have gaps; do not forget about the ends and corners. It is necessary to pay due attention to places that are most difficult to reach. Already after applying the first layer of paint, the roof is given an unrecognizable appearance, but you still shouldn’t stop there. The next layer is no less important.
You can start painting the finishing layer after the slate painted with the first layer has completely dried. Applying paint a second time will give the already painted roof a uniform color and get rid of streaks. As a rule, 1/3 of all paint is spent on this layer.
Painting slate by hand is not so much a long process as a labor-intensive process that requires certain skills.
The technology described above can be safely used for painting both wavy and flat slate. Thanks to this simple technology, roofs are given an aesthetic appeal that will decorate any building. And, of course, painting slate will increase its service life under environmental conditions.
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