It is known that restoring damage to the roof is a troublesome task and is far from being as simple as it might seem at first glance, and when it comes to repairing slate, repairing holes and cracks in an asbestos-cement sheet, one simply gives up, so The result of the repair is unpredictable. However, slate repair technologies exist and are successfully used in practice. As the classics say, nothing is impossible, you just need patience and a little accuracy in your work.
Causes of cracks and holes in slate
In order to choose the right method for repairing damage, you first need to understand the causes and conditions for the occurrence of a crack or hole. This will help seal the cracks in the slate on the roof so that the problem does not reappear in a short period of time.
Slate is rightly considered a very capricious, brittle and even brittle material, so there are many reasons for the formation of cracks:
- A technological defect, such slate is also called overdried. Due to the fact that during the manufacturing process of the sheet, the hydration of the cement base took place under conditions of lack of moisture, the material turned out to be too brittle. Such slate easily cracks even under light load; this is a defect, and repairing it does not make sense;
- Incorrect installation of slate. In this case, part of the sheet wave ends up on the roof without support from the rail. A crack may appear if you step on slate carelessly or drop a heavy tool;
- Incorrect installation of fasteners. If, when installing a slate roof, nails hit a dry sheet without drilling a hole, a very long and dangerous crack, or even a small hole, can form;
- Inept cutting of slate sheets. The most difficult operation when cutting material is making a hole for a pipe, especially in a situation where you have to cut close to the edge or the last wave. The only way to repair a hole in slate from a pipe is to install a double patch.
It is clear that extremely careful handling of the slate sheet reduces the risk of cracks, but the threat of holes in the slate cannot be completely avoided. Slate holds a static load well, but can easily split from the impact of a dropped electric hammer or screwdriver.
For your information! The likelihood of future repairs can only be reduced if the material is carefully inspected for surface defects before being lifted onto the roof.
It may even be helpful to lightly tap the sheet with a rubber mallet. If there is a defect or hidden crack, then it is quite possible to determine its location by the low sound. Such a sheet is sent for patching, this is easier than laying it on the roof, or after a couple of years looking for a way to carry out repairs or seal a leak in the roof.
The saving grace is that low quality slate, with possible cracks, is visible to the naked eye. Typically, roofers do not even recommend lifting onto the roof material with unevenly broken, not cut edges, a spotted or heavily dusted surface. Repairing substandard slate is a thankless task.
How to fill a hole in a slate roof
On the other hand, even if there is a sheet with a small crack in a pack of guaranteed quality material, this is not yet a reason to panic. It is always possible to repair a crack in slate from the inside, from the wrong side. Moreover, in conditions “on the ground” this is much easier to do than on the roof. You can patch or seal small holes in slate, for example, from nails or repair fasteners, but in this case you will need to soberly assess the nature of the damage and the possibility of further use of the sheet.
To repair slate roofing at home, the following methods are used:
- The crack is sealed with a viscous and elastic material with a good level of adhesion to the asbestos-cement surface. If the repair rules are followed, the crack does not allow moisture to pass through the roof and does not increase in size;
- Lay a slate patch. This is the only real way to patch a hole in a slate roof without having to replace the sheet;
- Concreting the damaged area. In this way, a relatively small sector of slate can be sealed; it is used for the most difficult cases;
- Blocking a crack or hole with foam. This is rather a temporary measure that allows you to close the hole for a short time, for example, in winter or in rainy weather. At the first opportunity, you will need to carry out a full roof repair.
It is easier to work with a crack than with a hole; you just need to find the reasons and carefully seal the damage. It's another matter if you need to patch a hole in the slate on the roof. In addition to the adhesive mass or binder, you will need to select a patch material that would be similar in properties to slate and easy to process. Typically, thin sheet metal, asbestos or basalt fiber are used to seal minor damage.
Concrete mortar
This is the most affordable option repair holes of any size. Cement and sand can be found in any household, so you can repair a hole in a slate roof in just half an hour. Prepared for repairs wooden box formwork, it can also be made in the form of a ring from the tread strip of an old inner tube.
The damaged area or hole is carefully cut to size so that the improvised formwork can be placed under the slate and secured. Next it is poured concrete mortar, and a patch made from a larger piece of slate is laid over the hole. Sometimes the edges of the repair patch are painted with oil or rubber paint.
Butyl rubber waterproof tape
The popularity of repair films made from butyl rubber is incredibly high, since elastic self-adhesive tape can be used to repair almost any crack, from a water pipe to glass on a balcony.
The tape is sold in the form of a reel, like adhesive tape, but, unlike construction and household strips, BC has high strength and good adhesion. In fact, this is the best option in a situation where the slate has burst and you need to repair the crack within five minutes.
For repairs, it is enough to cut a piece of tape of the required length and stick several layers so as to block the leakage of water on the roof through the cracks. If conditions permit, the sticker area should be coated with acrylic paint or any nitro adhesive. Butyl rubber adheres well to smooth surface, but on a rough asbestos-cement coating it can come off in the first rain. Therefore, the edges of the crack must be painted over before sealing.
Moisture-resistant nitrocellulose glue
Despite the convenience and relative simplicity, the use of expensive butyl rubber tape is not always justified. Firstly, this is an expensive material; the price of a reel can reach 12-15 EUR. Secondly, its use is reasonable for cases where the crack is located on a critical area of the roof, and, in addition to the tightness of the roof, the purpose of the repair is to keep the slate wave in the desired position.
For simple cases, for example, a crack appeared on the surface of the slate directly above the wooden plank of the sheathing, you can get by with ordinary nitrocellulose glue.
With the help of a good glue, you can fill up a crack in slate faster and cheaper than using expensive butyl rubber. For repairs, the adhesive mass is divided into two parts:
- The first half is diluted with acetone to a liquid state;
- In the second part, slate cut is added - shavings and dust obtained when cutting the sheet with a grinder.
The crack is treated with the liquid fraction in several stages, dried and a thick adhesive mass is applied, then a tape of construction tape is glued on. In the same way, you can cover up all the cracks in the slate on the roof if the size of the damage does not exceed a few centimeters.
Bitumen mastic
Before the advent of repair adhesives and polymer materials bitumen and roofing felt were actively used to repair all existing damage slate roof. It cannot be said that bituminous compounds provide the highest quality of repairs, but they are easy to use, affordable and do not require special preparation before use.
Advice! To repair slate, it is better to use ready-made liquid bitumen mastic.
Any options with melts of resins and solid bitumen require increased care, since a crack when the slate is heated can not only increase, but also lead to splitting of the entire sheet.
Using bitumen mastic it is convenient to apply repair patches. To repair a hole in a slate roof, simply do the following:
- Cut a rectangular patch from a sheet of repair slate;
- Coat the edges of the hole in the roof and the back surface of the patch with primer and one layer of mastic;
- Dry the prepared materials, reapply bitumen waterproofing and lay the patch on the repair site.
If the angle of inclination of the slope is large enough, then the slate patch must be tied with wire to the base of the roof or to the nearest support. After a couple of days, the seams are re-painted with mastic. Using small pieces of roofing material and mastic can be used to repair nail holes in slate relatively easily. True, this needs to be done from the wrong side, even before laying the material on the roof of the building.
Cement-asbestos mortar
Sealing a slate roof with repair mixtures based on cement and asbestos is considered the most correct from the point of view of the structure of the slate. Today, repairs using cement-asbestos mortars are considered outdated and unsafe, since you have to work with chrysotile fiber.
It is not difficult to cover up a crack in slate with a solution; you just need to apply a small amount of repair mixture onto the surface of the damaged area of the roof and cover with film for a couple of days from rain and wind. After the solution sets, a patch is obtained whose properties resemble slate material, so liquid asbestos cement is used to repair the most complex and severe damage to the roof.
Today, there is no real alternative that can replace the solution. Polymers and resins have not yet been developed that can be used to seal cracks in slate with a guarantee of 60-70 years of service.
The preparation of repair asbestos-cement mixture is carried out in the following order:
- In a metal container of 10-12 liters, or in a galvanized bucket, the asbestos fiber is pre-soaked for at least a day. For 5 liters of water, take 3-4 kg of fiber. After a day, the soaked powder turns into a gel-like substance;
- Cement grade 400, approximately 3-4 kg, is added to the resulting gel and mixed manually with a trowel until a homogeneous mass is obtained.
The mixture should be used within 3-4 hours, preferably in calm, dry weather. The quality of slate roof repair depends on the grade of cement and the extent of the damage.
Polyurethane foam and epoxy resin
The use of construction polyurethane foam greatly simplifies the process of sealing any cracks and damage, and especially holes. If, due to careless handling, a through break has formed - a crack, or, worst of all, a hole has appeared, then with the help of polyurethane foam you can reliably, and most importantly, quickly fasten a piece of slate of almost any size.
The technique for using polyurethane foam is very simple. The area of damage or hole formation is moistened with water, both on the roof surface and in the space under the slate. Next, blow the required amount of foam from the underside of the sheet so that the resulting layer of polyurethane foam fixes the edges of the hole. After 30 minutes, you can cover the damage with a patch using the same polyurethane as glue.
Foam materials are ideal for repairing breaks and large holes, but for repairing cracks, foam is too viscous. Epoxy resin is best suited for these purposes. You just need to add a thinner to help the glue penetrate the crack better. After treatment with the adhesive mass, the damage line must be covered with a patch made of film or thin foil.
Chalk and drying oil
This is an old, well-known recipe for sealing cracks and cracks in windows and building walls. The mixture can be used to repair cracks in slate. Thirty years ago, chalk, often tooth powder mixed to a paste, was used to seal the cracks between the glass and the window frame.
The quality of repairing cracks and holes was not high, so various auxiliary ingredients were added to the mixture, most often cement, casein glue or oil paint. The only advantage of this “sealant” is that it is convenient to seal the gaps between wooden beam and asbestos cement sheet. The putty adheres equally well to both materials, and over the course of a day it hardens to the state of stone.
Waterproofing coating composition
Usage liquid waterproofing based on acrylic or butyl styrene rubber makes repairs as simple as possible. Using a brush, a knife and a metal brush, you can repair cracks of any length and size.
Thin and long damages are expanded and cleared of debris, after which a primer is applied and thin layer waterproofing. Holes large sizes can be sealed using several layers of polyester fabric, glued on like papier-mâché.
Ready-made putties
You can also repair a crack in a slate roof using a putty compound. Best results obtained by using polyester, epoxy and acrylic putties with fiberglass fillers.
All other compositions based on modified cellulose and water-dispersed polymers are not used for repairing cracks and holes due to their high sensitivity to changes in temperature and humidity.
How to repair a hole in a slate roof
In order to complete high-quality repairs slate, without removing the sheet from the roof, you can use the most simple objects and things that can be found in almost any car enthusiast's garage. To fix a hole in the roof country house, required:
- Hand brace with a thin drill 4-5 mm;
- Thin copper or annealed steel wire with a diameter of 2 mm;
- Liter of gasoline;
- Remains of bitumen sheet, resin or a piece of raw rubber from a first aid kit;
- Hammer, chisel and ten nails;
- Oil paint.
Before you begin repairing the roof, you need to prepare rubber-bitumen adhesive. To do this, we dissolve bitumen and rubber in gasoline to obtain a viscous adhesive mass.
Advice! A hole in a slate roof can be easily repaired with wire, but a patch will need to be cut out first to make the repair. This could be a piece of slate or, in extreme cases, any material with a wavy profile.
In order to secure the patch over the hole, you will need to drill 10-12 thin holes along the contour of the overlay and the damaged area on the slate. Next, we thread the wire and pour homemade rubber glue to seal the cracks on the roof. After a day, you need to cover the drilling points with bitumen-rubber mass, always with outside roof coverings.
Sometimes craftsmen try to check the quality of the hole repair by pouring water onto the patch. If the patch is glued securely, then leakage will be minimal. In this way it will not be possible to seal the roof slate “tightly”; there will always be a couple of small holes left. Their position is determined by drops of water. To repair the holes, you need to completely cover the entire patch with paint.
Repairing a crack in slate is much easier:
- Pre-drill holes at the ends of the crack. This allows you to limit the spread and increase of damage;
- Using a chisel and hammer, widen the crack line by a couple of millimeters, after which bitumen-rubber glue is poured in and covered with a strip of plastic film.
For your information! If the crack is large and threatens the integrity of the sheet, then the edges can be tied together with wire, as in the case of installing a repair patch.
Such repairs will provide the slate with several more years of life on the roof of the dacha. Of course, this is just a temporary measure and cannot replace professional repairs.
How not to repair a slate roof
Coating from asbestos cement sheet is extremely sensitive to temperature changes, so high-temperature melts based on ceresin, resin and basalt powder are not used to seal cracks. These materials are used to repair cracks in concrete roofs and to seal holes and joints in panels and slabs.
Many problems arise with sealing damage with epoxy compound and pure resin. At low temperatures and severe frost, the materials become covered with cracks and gradually peel out of the seam.
Prevention of destruction
The durability of the roofing depends primarily on how correctly the slate is laid on the roof. Since asbestos-cement sheets are nailed directly onto wooden sheathing slats, the flow of water or waterlogging of the wood can lift the slate and even break the nails. To avoid this, the slats must be treated with water-repellent impregnation.
Most often, cracks and holes in slate appear due to improper driving of nails. It is best to drive the fastener into the sheet after the hole is drilled. If it is not possible to hit nails according to the rules, then the place on the slate surface must be filled with a punch and moistened.
Experts say that the cause of the breakdown is most often the careless attitude of the owners to the roof.
Conclusion
Asbestos-cement roof covering is remarkable in that any slate repair, repairing holes and cracks, setting nails or sewing up edges, does not require special equipment and knowledge. The quality of the work, despite the apparent complexity, depends on the type of materials used and the accuracy of the repair work. According to statistics, a slate roof needs repairs once every 10-15 years, even with ideal roof installation. Therefore, in addition to adhesive materials, it will be useful to have at least one ladder on hand and wooden stairs with support board.
No matter how beautiful it looks new roof, time flies inexorably. There comes a time when the property owner is faced with the question: how to repair cracks in the slate on the roof? There are many solutions to this issue! The choice is up to the owner, only he can prolong the operation of the slate roof.
In this article
Defects in slate roofing
List of slate defects that may appear during roof operation:
- the appearance of cracks in slate;
- overgrowing of material with moss;
- mechanical damage;
- defects in the roof structure remaining after installation;
- physical aging;
- other flaws.
When the owner decides to cover the roof with slate, he knows what awaits him ahead. Heavy transportation of material to the workplace. Low aesthetics of the material, its fragility, extra work for its improvement. But, overpowering the budget cost of the material, its versatility - it was these indicators that enabled slate to become popular.
Experts advise: in order to long-term protect the material from the appearance of lichen and moss, use special antiseptics. This design will increase the operating time.
Slate cannot be called the most technologically advanced material. But holes, chips, mother-in-laws, any flaws can be repaired. Naturally, simple patches will not save you. We will have to allocate funds to eliminate the shortcomings. While the roof is new, it is advisable to immediately provide rules for cleaning the material and caring for it.
Preparatory work for repairs
Before making repairs, the slate must be cleaned with a broom and water. Remove all foreign objects, dirt, debris, soil. After cleaning, determine what type of repair is required. It can be radical, that is, complete. They mean replacing the entire system: rafters and coverings. This type of work is used when sheets of material and rafters are severely damaged.
Then a different design of sheathing and rafters is required. Partial renovation performed when it is necessary to remove the old slate and put in new sheets of material. During cosmetic repairs, flaws in slate are repaired with patches using specific compounds.
Methods for sealing cracks
Repairing cracks in slate is the most common option. There are many solutions to the problem. If a crack is found on the sheet, it and the area around it must be degreased with gasoline, acetone, or solvent. Then the area should be treated with a primer with a base of PVA glue. Fill it with an insulating mixture, possibly a cement composition.
Repair mixture
Mixtures are made from water, asbestos, cement, and PVA glue. It’s simple to do: add three parts asbestos to one part of cement. PVA construction adhesive and water are added to this composition in equal quantities. Then mix everything carefully until a mixture with a thick consistency is formed.
The mixture is made in small portions! This is done for its long-term preservation. The defect is sealed with the resulting mixture in two layers. The thickness of each must be at least one mm. IN construction stores ready-made formulations are available for sale. They are based on waterproofing materials. You can use this composition, but preliminary degreasing of the material before repair is always carried out.
You can work with the same composition, but only diluted xylene. The defect site is first coated with a primer, then covered with a compound. As soon as six hours have passed, you need to put fiberglass on this layer. And, reapply a layer of sealant.
Application of aluminum foil
To complete the work, prepare a patch with the necessary parameters. The corners of the patch should be rounded. The inside must be coated with universal glue. Then, with a little force, press it onto the slate sheet from which the old fasteners have already been removed. After applying the patch, the sheet of material is attached to the roof with nails. This must be done through prepared holes. But they must be located in new places.
Advice: construction foam– also an option for sealing defects in slate sheets. And the most permanent and accessible! If several layers of polyurethane foam are applied to the defect. Then after it hardens and dries, it is cut along the contour of the wave of the material, and a layer of sealant is applied on top. Then the area is dried and a layer of bitumen resin is applied.
Sometimes sealing butyl rubber tape is used as a patch. It is self-adhesive and double-sided work surface. On its top there is decorating material or non-woven fabric. And there is an adhesive base, it is protected by a strip of paper. It is anti-adhesive, or a polymer can be used for the same purpose. It is with this strip that the damaged area is sealed. The upper part of the strip can be painted in your preferred color if desired.
Is there some more simplest method to eliminate defects in the material. Thick fabric should be placed alternately on the defective area, then it should be treated with nitro paint.
It is also fashionable to repair a crack in slate directly on the roof without removing the sheet. Then you need to use silicone paste. First, the crack is filled with slate chips, then filled with silicone.
Another method: if the crack is small, then holes with a diameter of up to four mm should be drilled along its edges. Then fill it with hot resin or special roofing sealants. They will dry out and become like rubber.
Safety precautions
The work of repairing materials on the roof, like any other work, requires strict adherence to the rules for the preservation of people. The person performing the work must have appropriate special clothing. Non-slip shoes must be worn on your feet. The work is performed in calm, not sunny weather, without rain or wind. If necessary, you need to invite one more person. This is done to insure against an accident.
Once upon a time, slate roofing was considered perhaps the most versatile: affordable, durable and unpretentious. Cheap and cheerful, as they say. But for all the strength of asbestos fibers, such sheets are not very resistant to mechanical loads: over time, many small cracks always appear on them, through which moisture easily seeps. Fortunately, a slate roof is at least not subject to corrosion, like a metal roof, which is covered rusty spots from the slightest scratches, and yet repairs will still have to be done from time to time. So how can you repair a crack in slate and stop further destruction of other sheets? Now we will understand everything in more detail.
Why does a slate roof collapse?
Fragile slate is damaged quite easily:
- From shock loads. From careless walking on the roof.
- From microcracks due to falling tree branches.
- From mosses, lichens and other misfortunes. Moss and lichens, which especially love slate, not only deprive it of its aesthetics, but also slowly destroy it!
- From time. Unfortunately, the service life of a slate roof is not long, and after 10-12 years the first cracks and holes appear.
- From constantly stagnant rainwater. Any roof, and not just slate, has weak spots around it skylights and pipes. Pay attention to these elements right away - sealing them is not difficult.
- The roof angle is not suitable for slate roofing.
- The slate was laid with certain violations, and the material is constantly under excessive stress. It’s also bad if during installation you used ordinary nails without rubber gaskets to fasten the sheets - you won’t be able to avoid cracks later.
- Inaccurate transportation and storage. Such defects may not be detected immediately, but they will immediately become noticeable when walking on them on the roof.
- Sudden temperature changes. Believe me, any asbestos-cement material does not like this.
- Due to disproportionately small holes for screws or nails. Don’t forget that metal tends to expand seasonally, and therefore you need to leave a little more space for such fastening (but not so much that it flows). rainwater). This is why rubber gaskets are needed.
And finally, snow can add new problems. The fact is that a slate roof is not as smooth as a metal roof, and snow constantly lingers on it. And a few sun rays are enough to flood this entire snow cap from below - as a result, the melted water flows down to the cornice, where it meets a new layer of snow (the cornice is always colder than the roof above living quarters). Here the melt water freezes again and, in the form of ice, destroys not only slate sheets, but also drainage system. In addition, all this mass, under natural expansion from the low temperature, is driven under the sheets and from there, melting, falls directly onto the rafters or into the insulation.
Also, often the cause of cracks in slate lies in its incorrect manufacturing technology. And at several stages:
- During the preparation of the solution, less cement was added than required by the factory recipe (guess why).
- Gross violations of slate sheet production technology (handicraft production).
- Short asbestos fibers were used in the slate (and this was the manufacturer’s decision).
- Poor quality processing of finished slate sheets (lack of control).
- Reducing the material opening period (it takes 28 days).
Now let's talk about how and with what to seal holes and cracks on the slate roof of a house.
How to detect coating defects?
Agree that it is quite difficult to notice new defects or cracks on an externally heterogeneous slate roof, while on a smooth seam roof or corrugated sheeting this is easy to do even from a neighbor’s building. Therefore, pay attention to these warning signs that your roof needs to be repaired urgently:
The fact is that undetected leaks are quite insidious: the rafters immediately become saturated with moisture, the thermal insulation becomes damp and deteriorates, and the ceiling needs repairs. Go into the attic if you have these suspicions: if you smell damp, there is a problem. And individual spots of mold indicate that there is a crack in the slate somewhere, but so far it does not make itself known except for small leaks. Also check the under-roof area of your slate roof after every rainstorm.
We make a “diagnosis” based on sheet cracks
If the cracks appear along the protruding waves of the slate, then the fillers must be applied both from below and from above.
Cracks in the lower waves require the most difficult decisions. After all, this is where water will constantly stagnate, and it is quite difficult to achieve the necessary tightness.
But let's first look at the crack itself - a lot depends on this:
- A crack that runs along the top wave of slate(it is easiest to notice) usually does not leak due to the fact that the water under it does not stagnate. This is the most harmless crack, and it is easy to repair - just bend galvanized iron and slide it under the slate, and cover the crack itself with a special roofing tape.
- A crack that runs along the lower wave, the most dangerous - you can’t do without leaks here. Use caulk, patch and bent sheet.
- A crack that runs across a slate sheet, the most dangerous! And leaks alone are not enough - the crack will begin to expand and will move on to subsequent waves in the future.
Have you decided on your future renovation? Proceed with caution! Remember that in many countries of the world this roof covering is completely prohibited due to harm to health, so when dismantling old sheets or mechanical processing, protect yourself from asbestos fibers. Here's how professional teams do it:
How to repair cracks and holes in slate?
Before applying any patch, it is important to completely clear the surface to be repaired of debris and moss, and then wash it with a powerful stream of water. Here's how to fix holes and holes in the slate roof available materials and new products on the construction market:
Method number 1. Cement and sand
Prepare a mixture of one part dry cement and two sifted sand. Pour in water and knead to the desired consistency. Close it up. Let the cracks dry thoroughly and paint them in a suitable color.
Method number 2. Butyl rubber tape
A special butyl rubber tape is also good as a patch for holes and cracks. What’s good is that its surface is made of non-woven material, making this patch easy to paint in the desired shade. And it’s also easy to work with:
- Step 1. Degrease the area of the slate sheet to be repaired with gasoline.
- Step 2. Remove the protective strip from the tape and stick it to the damaged area.
- Step 3: Paint in a color so your roof doesn't look patched.
Ready-made butyl patches are also used for repairs:
To seal slate cracks, serpyanka is also used - a tape that gives strength to the putty joint of the sheets. To do this, a layer of bitumen is first applied to the crack, then serpyanka is applied to it, and then everything is coated with bitumen again.
Or use a more expensive one modern version tapes that are designed specifically for repairing such roofs:
Method No. 3. Hot bitumen
It’s not difficult to prepare bitumen mastic over a fire:
- We light a fire and place two bricks on the sides.
- We take an old bucket and put a piece of bitumen in it.
- Place the bucket on the fire and stir carefully so that nothing catches fire.
If you work at sub-zero temperatures, add 10% waste to the bitumen to give it elasticity and prevent cracking of the mastic. Especially if you are processing the edges of slate sheets:
Hot bitumen is also suitable for sealing small cracks:
But remember that any putty gives only a temporary effect. The problem with using traditional slate putties is that this roofing material has little flexibility for expansion, whereas putties usually have a completely different coefficient. This is why, after a few cycles of temperature fluctuations, leakage problems return again. And sometimes it is much easier and more reliable to simply replace the defective sheet.
Method number 4. Putty made of asbestos, cement and PVA
First we take asbestos into finished form. If you can’t get one, just grate it on a grater made from a piece of slate. Be sure to protect your respiratory tract while doing this!
So, to prepare the mixture you will need to mix 2 parts of cement, 3 asbestos and a liquid solution of PVA glue and water, taken equally. Stir the mixture until it thickens like sour cream. If you cleaned part of the slate before repairing, wait until it is completely dry. Next, apply the prepared mixture, treat with a solution of PVA and water (now the ratio is 1:3) and apply 2 more layers of the mixture.
Method No. 5. Ready-made putties
Well suited for repairing such roofs ready-made mixtures, which include waterproofing materials. You need to work with them like this:
- Step 1. Clean the surface to be repaired well.
- Step 2. Degrease the area using solvent or acetone and dry thoroughly.
- Step 3. Prime the surface with a repair mixture, only diluted to a liquid state.
- Step 4. Apply the mixture using a special gun or spatula.
- Step 5. After 6 hours, cover with fiberglass and add a new layer of mixture.
Please note that such renovation work on a slate roof it is necessary in dry and cloudy weather so that the necessary components in the mixtures dry without rushing.
Method number 6. Foam and epoxy resin
They also seal cracks and holes in slate. liquid foam, but for this you will have to purchase a whole cylinder. The so-called “three-layer” method is also practiced among home craftsmen:
- Step 1. Clean and degrease the area.
- Step 2. Seal the crack with foam.
- Step 3. Dry or just leave for a day.
- Step 4. Apply sealant.
- Step 5. Cover it all with resin.
Epoxy resin is also suitable for repairing slate roofs, as it is much less destroyed by ultraviolet rays than polystyrene foam.
This is an expensive but reliable method for dealing with small problems, although it is inconvenient to use on an inclined plane. So, if the slate sheet is split along its entire length, fasten the wavy joints with epoxy glue. But first, secure them together at the bottom with mounting adhesive tape, and only then fill the gap at the top.
Method No. 7. Tin patch
This method is suitable for repairing large holes and cracks in a slate roof. So, step by step:
- Step 1. Cut out the patch from tin and roll it into a tube.
- Step 2. We push it into the hole so that a hole can be made in the middle of the patch.
- Step 3. Insert a bolt with a gasket into the hole and press it.
- Step 4. Fill the gaps with construction sealant.
Slate roof repairs need to be taken seriously. If the patch continues to let even a little water through, the rafters will eventually become completely unusable.
Method No. 8. Drying oil with chalk
This is one of the most proven traditional methods. So, we clean out the cracks, cover them thoroughly, and when dry, paint them with oil paint. That's all!
Method number 9. Moisture resistant glue
- Step 1. Wash the sheets well with plain water and scrub them with a stiff brush.
- Step 2. We wait for the slate to dry and seal each hole with a piece of thick fabric so that its edges extend beyond the hole by about 3-4 cm. To do this, saturate the patch with moisture-resistant glue.
- Step 3. Once again apply a layer of glue (Emalit) on top of the patch.
- Step 4. Turn over the damaged sheet and fill the hole with concrete.
- Step 5. Once the solution has set, glue another patch.
- Step 6. Drill a hole at the end of the crack and seal it with elastic sealant.
Method No. 10. Aluminium foil
Ordinary aluminum foil will also help to cope with cracks:
- Step 1. Remove the previous fasteners from the sheet.
- Step 2. Round off the corners of the patch.
- Step 3. Attach the foil and press it with a self-tapping screw.
- Step 4. If the slate on your roof is colored, paint the patch the same color.
In extreme cases, it is easier to replace a section of slate roofing than to repair it. Then cut out the necessary elements from the new sheets:
Often the ridge of a slate roof also becomes unusable, which is not difficult to replace with a metal or wooden one:
How to protect slate from further damage?
The situation is worse if the roof begins to burst in different places. This usually indicates installation errors at the time, and normal repairs slate on the roof will only give a temporary effect. It is urgent to stop the destruction process:
- Method number 1. To prevent cracking, temporarily place a strip of paint-soaked cloth over the crack.
- Method number 2. Also, to prevent the crack from spreading further, a hole is drilled in it and fixed with a self-tapping screw. Moreover, such a hole must be additionally sealed with roofing sealant, which will tighten the edges of the hole like rubber.
But, if you are not going to replace the entire roof in the next decade, then approach the issue of repair more globally:
That's all! Choose a method for which you already have materials and know how to work with them.
Slate repair - how to repair holes and cracks?
The most proven methods for repairing slate roofing: from budget patches to modern rubber tapes.
8 Ways to Fix a Crack in a Slate Roof
Despite the wide range of roofing materials, slate today is no less popular than it was a couple of decades ago. This demand for coating is due to its relatively low price. At the same time, the relevance of the material is very justified if the roof has a simple configuration (1-2 slopes). However, it is worth knowing that over time, the strength of slate decreases significantly, which provokes the appearance of small and large cracks or holes on it. Therefore, in the article below we will learn how to repair a crack in a slate roof or how to deal with a hole in it.
Causes of slate destruction
In order not to look for an answer to the question of how to seal slate, it is worth knowing that holes or cracks in it can appear for various reasons that can be prevented. But the main ones are:
- Wear of the coating over time. As a rule, after 10-15 years the material becomes more brittle, which provokes susceptibility to point impact loads (fall of an icy branch, fruit, etc.).
- The tendency of slate to accumulate moisture in shaded areas of the roof. In this case, where the coating sheets are more moist and there is no direct sunlight, moss is growing. As a rule, this is the north side of the roof. Moss is a destructive organic substance for asbestos cement.
- Incorrectly assembled roof drainage system. If rainwater stagnates in certain areas of the roof, the strength of the coating will begin to decrease, which will lead to the appearance of cracks or holes over time. Here it is worth taking into account non-compliance with the operating conditions of the slate. That is, if the slope angle of the slopes is not met, water will stagnate on the roof.
- Gross violations when laying slate sheets. In particular, we are talking about the use of simple nails without rubber gaskets to fix the roofing sheets and the incorrect laying of the sheets, in which the roof is now under constant stress.
- Inconsistency of holes for nails and screws when laying the material. If they are too small, then over time the metal, which is prone to seasonal expansion, will destroy the structure of the asbestos-cement sheet and holes will appear on its surface that will require restoration.
- Failure to comply with the conditions of transportation and storage of the coating. In this case, small microcracks will be invisible at first, and then you will have to look for the answer to the question of how to repair a crack in slate.
Important: if all of the above possible reasons The appearance of cracks on slate is not about you, it means that you purchased a substandard product that was produced with gross violations of technology. In particular, the proportions of the components could be violated, short asbestos fibers were added, or poor-quality final grinding/treatment of the coating was carried out with a reduction in its settling time.
We identify defects on slate, crack danger level
To see a crack on a slate sheet, you need to use special telescopic equipment, since such violations of the structure of the asbestos-cement sheet are difficult to notice with the naked eye. In order to understand whether a slate roof needs to be repaired and whether there are holes/gaps/cracks in it, an assessment must be carried out attic floor And rafter system from the inside. That is, according to appearance insulation and wood rafters can indicate possible leaks in the roof. They will be evidenced by:
- Wet and rotting rafter wood;
- Stains and mold on insulation or other components of the roofing pie;
- Stains on the attic floor in a specific area.
If a leak is identified, it is worth determining the level of danger of the leak. So, let's look at the types of cracks:
- If the crack is located in the lower ridge of the roof slate, then urgent restoration of the roof covering is needed. Because over time, water will simply spill on the heads of the residents of the house. After all, it is in the lower ridges of the roofing wave material that water accumulates in maximum quantities.
- If the hole has formed on the upper crest of the coating wave, this is a less dangerous option, but still requires thinking about how the cracks in the slate are sealed.
- And finally, the most unpleasant from a prognosis point of view is a transverse crack. Here, a hole can spread to neighboring waves, which will lead to the breaking of the entire covering sheet. Therefore, it is best to replace it completely.
Important: When starting repair work, wear protective clothing. Because asbestos fibers are toxic to human health.
Slate sheet repair
It is worth knowing that any repair manipulations with slate should be carried out only after it has been cleaned of debris and moss, thoroughly washed and dried. In addition, you should degrease the crack or hole with cotton wool soaked in solvent or acetone.
Repair option 1
If you don’t know how to fill holes in slate, then the simplest and most old-fashioned method One way to seal a hole is to use bitumen mastic. Previously, only it was used to cover up any holes in the walls of the house or fence/roof. It is simply prepared in a bucket over a fire, melting it to a viscous state. If repair work is carried out in cold weather (with minuses), then about 10% of the waste must be added to the bitumen mass so that the mastic is plastic. The crack is gradually filled with the finished mixture, leveling it level with the sheet.
Important: but it is worth remembering that this method of repairing cracks in slate is not the most reliable. The fact is that bitumen mastic tends to expand at positive temperatures and contract again in the cold. As a result of such deformation, after several cycles of temperature changes, the hole will leak again.
Repair option 2
Or you can use a cement-sand mixture if you don’t know what and how to fill holes in the slate. To prepare the mixture, you need to mix the above components in a ratio of 1:2. Dilute the mixture with water to the consistency of thick sour cream. The resulting solution is used to cover holes and cracks and leave to dry in the shade. The finished repaired sheet can be painted in the desired color.
Repair option 3
Also, to seal slate roofs, you can use a ready-made putty solution without having to bother with special inventions. The mixture can be purchased at a specialty store. Before applying it, the surface of the crack or hole must be well primed. Then putty is applied to the hole and after six hours it is covered with a piece of fiberglass. Another layer of putty is applied on top, and thus the use of a sealing combination saves the slate.
Important: apply putty mixture You can use a spatula or a gun. In this case, it is better to carry out repairs in dry weather with heavy clouds, so that the putty can dry without haste.
Repair option 4
And here, in order to cover a slate roof, you can use a mixture of cement, asbestos and PVA glue. This mass is very plastic and fits well into all the joints and gaps of the slate.
So, let's prepare the mixture:
- First, mix equal parts water and PVA glue. Mix everything well until smooth.
- Now mix cement and asbestos in a separate container in proportions 2:3.
- Mix all ingredients until very thick sour cream.
- In a separate container, prepare another PVA solution from three parts water and one part glue.
- Cover the finished, degreased and dried surface of the crack with the resulting mixture of glue, cement and asbestos. Lubricate the top with additional glue solution. And again we apply two more layers of asbestos cement on top.
Repair option 5
And in this way you can seal holes from nails that have crumbled over time and now allow water to pass through. In this case, you need to take a piece of aluminum foil and cut a patch out of it according to the right size holes. The foil is greased with universal glue and the patch is placed on the hole.
Important: in this case, the hole for the self-tapping screw will now have to be made in a different place on the sheet.
Repair option 6
Here, to repair a large break or nail hole, you can use tin for patching. A piece is cut out of it, rolled into a tube and, crushed, pushed into the hole. It is necessary to compact the tin so that it fills the hole as much as possible. Now a hole is drilled in the tin plug for a self-tapping screw and the slate is fixed to the roof using a high-quality rubber gasket. In this case, water will not flow under the roof.
Repair option 7
Repairing holes in slate will also help with regular polyurethane foam. Craftsmen use it to fill cracks and crevices in slate roofing. This is a good answer to the question of how to repair and seal slate sheets. The mixture is applied to a clean and grease-free repairable area, and thus the hole is sealed. Then, after drying, the crack is treated with sealant and everything is lubricated with epoxy resin.
Repair option 8
Often craftsmen seal cracks in ACL with butyl rubber tape. By the way, it is good for painting, which will allow your roof not to look patched. The tape is laid on the cracks in the slate after they have been cleaned and degreased. They press well, and after drying they can be painted in any color.
Important: a sheet of slate with repaired holes and cracks will last a maximum of 3-5 years. Therefore, at the first opportunity, it is better to change the covering sheet. Otherwise, the cost of restoring a rotten rafter system can be much greater than the cost of new slate and the work of replacing it.
How to repair a crack in slate on a roof or a hole caused by nails
Identifying slate defects on the roof and how to repair the crack? Causes of material destruction. Description of options for repairing slate, filling holes and cracks.
Roofing made from asbestos cement sheets is famous for its durability. However, even with such wear resistance, damage to slate during operation cannot be completely ruled out. As a rule, after ten to a year and a half, chips or cracks can be found on its surface.
Repairing slate can extend the service life of the roof by about another ten years, so the question of how to repair the coating is very relevant. Once upon a time, slate roof repairs were carried out using ordinary oil paint and fabric strips. The effect of such intervention was short-lived - only a few years. Modern materials make damage repair methods much more effective.
How to repair cracks
When slate leaks, it means there are cracks in the covering. There are several fairly simple methods that really help restore its functionality. All of them are available for self-execution, you just need to know how to seal the slate. This usually involves applying a patch to the damaged area or using a sealant. Let's see what needs to be done when the roof leaks, what is the best quick way, how to patch a slate roof, how to glue it together. This is especially important in bad weather conditions.
Let's look at the most common technologies for restoring damaged sheets. So, the slate has burst and is leaking. How to seal it, seal it? The simplest option- This is asbestos paste.
Step-by-step instructions for using asbestos paste
Preparation of the composition
The mixture is a composition that includes asbestos and cement; you can prepare it yourself. In a separate container, mix the powder components (take three times more asbestos) and add equal volumes of water and dispersive polyvinyl acetate glue until a homogeneous creamy mass is obtained. The mixture must be mixed very thoroughly to avoid lumps forming. Work with asbestos mixture is carried out in a respirator.
If the composition is not used for a long time, it loses its qualities. Therefore, it is advisable to knead it in small portions.
Application method
Before sealing the slate, prepare the damaged area:
- remove garbage;
- wash the damaged area and degrease it, for example, with gasoline;
- in the case of an ordinary crack, a fiberglass tape (serpyanka) is fixed along its entire length, which is at least 5 cm longer than the crack.
- significant damage or holes are first filled, e.g. raw rubber or caulked; for greater effect, the fibrous material is pre-treated with hydrophobic compounds.
The asbestos-cement composition is applied to the damaged area gradually, in successive layers as evenly as possible. The total layer thickness must reach at least 2 mm. When the patch is dry, the resulting seam is treated with sandpaper.
It is desirable that the mixture significantly covers the damaged area.
Such repairs will protect the under-roof space from moisture penetration for 8–10 years.
Using foil
The patch on the roof could be made of aluminum foil, even from an ordinary chocolate bar. Universal glue is applied to it and applied to the damaged area from the wrong side. To prevent the corners of the patch from bending, they are rounded. The connection between the foil and the roof is strong and will reliably protect the roof from water.
If the crack passes through the fastening area, then first seal it with foil and drill a hole for the fastening element in another part of the sheet.
After the work has been completed, the dismantled sheet is returned to its place. We must not forget that rubber gaskets for nails are a mandatory requirement. When the work is completed, the patch is masked to match the tone of the roofing. The paint is applied in dry weather; it is advisable to use a roller or brush. The best effect can be achieved if you treat the repaired area in two approaches, with a break to dry the first layer.
These methods are much more convenient if performed on a removed sheet.
Repair of asbestos cement roofing without dismantling
There are some methods for repairing a roof made of asbestos cement material, for which the damaged sheets are not dismantled. This work is performed directly on the roof, so insurance must be provided.
Sealing cracks with silicone paste
Cracks can be covered with silicone paste, which has good adhesion to asbestos-cement coating. The damaged area is carefully cleaned of dust and small asbestos chips using a metal brush. Then it must be degreased. To do this, you can use, say, acetone or a special solvent. Asbestos chips are poured into the crack in an even layer.
The next step is to fill the crumbs with silicone paste, let it set and paint it to match the color of the roof. This work takes little time, but the result is quite reliable.
The repaired areas of the roof are painted over as soon as the silicone paste sets. This is necessary due to the porous structure of asbestos cement sheets, due to which the repaired surface around the edges quickly becomes dirty.
Using polyurethane foam
The damaged area is cleaned and degreased. Next, the crack is blown out with foam, but not completely. The area to be repaired is dried and excess foam is cut off on the sides, after which a layer of sealant is applied. The work is completed by covering the restored surface with bitumen mastic.
Mastic for repairing damage
Sheets with joints are treated with mastic with a reinforcing filler of a wavy structure.
Small pieces of bitumen are melted in a separate container. This creates foam and impurities, which are removed during the process. Melting at 200–220°C is continued until the bitumen is completely dehydrated. Then filler is added to small portions of molten bitumen, which is preheated to 110°C.
Hot mastic is applied to the joints with a spatula or other suitable tool. During the application process, the material is smoothed. In this way, excess moisture is removed and the mastic is firmly compacted.
Another option for sealing cracks is to use self-adhesive butyl rubber tape. It has exceptional adhesive characteristics to any substrate. After gluing the crack, a high-quality lining is formed that excludes the ingress of water and is resistant to any atmospheric influences, ultraviolet radiation, and temperature changes.
To increase the adhesion of repair materials, it is advisable to prime cracks or chips with PVA glue.
Repairing significant damage
It is possible that during a roof inspection a sheet will be found split along its length; it can be glued together using epoxy resin. First, parts of the sheet are fastened from the inside with adhesive tape, and only after that the gap is filled with epoxy resin.
If the slate sheet turns out to be severely damaged, say, partially destroyed, or an impressive hole has formed on it, even several, its complete replacement is necessary. Partial repair of old slate in this case is ineffective. Not only will it not provide the coating with the required characteristics, but it will also not stop further damage and soaking.
Slate repair: use of mastic, primer, sealant
Some time after installation, a roof made of asbestos cement sheets may lose its original appearance; cracks and chips will form on it. It's unavoidable
Being the most durable roofing material, slate has been used to cover buildings since the middle of the last century. But despite all of it positive traits, time and mechanical stress can cause unexpected damage. And in this case, it is very important to know how to repair a crack in slate, or eliminate the resulting chip.
A crack in the slate – is it worth sounding the alarm?
To avoid the need to completely replace the sheet, which is not an easy task, you can use various methods correcting the defect that has arisen. And, despite the requirement for certain skills, it is easier than replacing the entire sheet.
Most often, damage occurs due to the “aging” of slate. But besides this, there are other reasons:
- the kit included a sheet created in violation of manufacturing technology;
- poor quality of processing of the sheet itself at the final stage;
- low-quality asbestos material;
- error in choosing the angle of inclination when laying it;
- violation of the order of laying sheets, which caused additional stress;
- no special nails were used to fasten the slate;
- the crack appeared during or cutting;
- the entry of solid material onto the roof as a result of gusts of wind or the pranks of children.
Often roofing manufacturers do not adhere to curing time requirements. It is defined by standards at 28 days. But, as always, profit becomes the priority. Many reduce this period by sending uncured sheets for sale. This is the main reason for the increased fragility of slate. But the experience of roofing craftsmen is the source of many recipes that allow you to repair cracks and chips in slate.
Our advice and knowledge will help you choose the most suitable way. It is important to ensure that the problem is resolved as quickly as possible. Especially when weather conditions do not allow you to think for a long time.
Slate crack repair - ways to restore damaged sheets
One of the options, when sealing cracks in slate, requires the presence of a repair mixture, which is prepared independently. It contains: asbestos, cement, water, PVA glue. The preparation of the mixture should be carried out in compliance with the ratio of asbestos and cement - 3 to 1, water and PVA glue are added in equal quantities to obtain the consistency of homogeneous sour cream. It is very important to pay attention to the mixing process - do not allow the formation of lumps.
Before applying the solution, the crack must be prepared. If it is just a crack, then a serpyanka (fiberglass tape) is fixed on top of it, along its entire length. If there is significant damage or a hole, it must be filled, for example, with raw rubber. You can now apply the resulting solution over the damaged surface, trying to do it evenly. Moreover, it will be very good if the mixture significantly covers the damage area.
Another method is based on the use of special aluminum foil. You must first apply universal glue to the foil, and then apply it to the damaged area. This provides a very strong connection between the foil and the roof, preventing water from entering. There is another way to cover up cracks in slate. Silicone paste should be available for these purposes. The previously damaged slate area must be cleaned, degreased and dried. The paste will adhere well only to such an area.
The fourth option, demonstrating the possibility of how to repair a crack in slate, is the proven method of using butyl rubber tape. Self-adhesive tape has high adhesive qualities. It is capable of sticking very firmly to almost any material - wood, plastic, iron, glass, film. When gluing a crack on asbestos slate, a high-quality lining is obtained that does not allow water to enter and can withstand any climatic influences and temperature changes. This tape is not afraid of dirt, dust or ultraviolet radiation.
Based on the options described, you first need to decide what is best to cover the cracks that have formed in the slate, or use tapes to get the most efficiency from the method used and lower costs for this repair.
How to repair a crack in slate - basic rules
The primary step in the process is always preparing the repair area. Under no circumstances should you begin work if this step has not been completed. Each material, and especially the repair solution, is most effective at the very beginning after its preparation. Any delay leading to its untimely use may result in practical failure. The solution will lose its properties and will not provide quality protection.
First, the garbage is removed. The damaged area is thoroughly washed and degreased. You can use gasoline here. When working with asbestos solution, it is necessary to use a respirator. The mixture does not need to be prepared in large quantities. Its properties are lost if not used for a long time. It is enough to mix in small volumes, covering the crack area gradually. The solution itself is poured into the crack sequentially, twice. It is required to achieve a layer thickness of at least two millimeters.
If the damage is significant - the split has occurred along the entire length of the sheet, you can use epoxy resin for gluing sheet parts. Previously, adhesive tape is used from the inside for connection. You can use a fixed galvanized patch - silicone or bitumen mastic is used in the junction area. This option is often used if the crack has spread across the entire surface of the sheet, starting from the site of the previous repair. To do this, old fasteners are removed. After repairing the sheet, both parts of the slate are attached in new places.
Among the various repair methods, there is a method that uses polyurethane foam. In the case of large holes, it is blown into the damaged area, following the rules for using such material. And here one condition must be fulfilled - when the foam has hardened, it must be cut along the contour of the sheet. By outside slate along the damage, the foam itself must be protected by a sealant. It is additionally treated with roofing mastic, which is intended for waterproofing roofs.
Repairing a crack that has damaged a slate sheet will be successful if you ensure high adhesion of the materials - it is better to prime the damaged area with PVA glue.
And one more very important rule. In case of severe damage, for example, partial destruction of the sheet, the formation of significant or even several holes, the only solution is to completely replace such a slate sheet. Repair will not provide the slate with the required properties and will not be able to protect it from further damage and soaking. And this in turn will lead to leakage. In addition, the consequence will be meaningless financial and labor costs.
Slate roofing has been very popular for a long time.
Such popularity was achieved due to the low cost of the material, good performance, and ease of installation.
Today in European countries It is prohibited to produce materials containing asbestos cement.
In Russia, slate continues to be produced, and it is in great demand, although there are many other roofing materials with a similar cost.
But in most cases, after ten to fifteen years, a slate roof loses its strength and cracks appear on it. But it is not always necessary to completely replace the entire roofing covering.
You can carry out minor roof repairs, the purpose of which is to seal small cracks and holes in the slate sheets. Sometimes such repairs are quite a labor-intensive task. This article will tell you how and with what to fill holes in slate.
Asbestos slate has a long service life, but over time, under the influence weather conditions it loses its protective properties. The reasons for failure may be improper installation of roofing material, walking on slate, improper transportation, etc.
1) Damage received during transportation of the material. Small cracks and chips appear on the slate, which may go unnoticed at the time of installation.
It would seem that such minor flaws should not cause trouble. But after some time, such cracks can cause serious damage.
2) Damage that occurred during the laying of sheets. Small cracks caused by strong nail pressure during installation can cause major damage.
This may result in the need to completely replace the roof covering. Over time, small cracks become larger and develop into holes. Pieces of slate break off at the fastening points.
3) Incorrectly drilled holes for fasteners can also cause cracks in the material.
According to technology, the diameter of the hole should be larger than the diameter of the nail, but this rule is often forgotten, as a result of which, after some time, chips and long cracks may appear on the slate.
4) Cracking of the slate sheet may also occur due to temperature changes. Asbestos slate absorbs water well and when there is a sharp cold snap to sub-zero temperatures, it becomes fragile.
Even a slight blow to a slate sheet can cause it to fall apart. Therefore, it is advisable to check the roof in the spring and replace damaged sheets with new ones.
5) Another reason for the appearance of defects may be careless movement on the roofing.
Over time, lichens and moss may appear on the roofing, and if they are not removed, the slate may lose its protective properties.
How and with what to fill holes in slate?
The choice of roofing restoration method depends on the size of the damage and its type. There are 3 ways to repair damaged coating:
— Major repairs (and the rafter system). This method is used if the rafters and roofing are severely damaged. It is also used when completely changing the roofing material to another, which requires a different design of the rafter system and sheathing.
— Selective replacement of sheets. In this case, sheets with holes, chips and cracks are replaced. You also need to check the condition of the roof structures.
— Performing cosmetic work, which consists of sealing holes and other minor defects. To do this, you need to apply patches or seal cracks using special mixtures.
But how can you fill holes in slate to achieve maximum effect? You can buy a ready-made mixture or make it yourself.
Let's look at the second case first.
First of all, we clean the surface to be repaired of moss and accumulated debris. Then rinse it thoroughly with a powerful stream of water. While the surface is drying, we prepare a mixture consisting of cement, asbestos and PVA glue.
First, we buy asbestos ready-made or grate it from a piece of slate. Asbestos is harmful to the body, so when performing this work you need to protect your respiratory tract. To make the mixture itself, we take 3 parts of asbestos, 2 parts of cement and a solution of PVA and water in a one-to-one ratio. Stir the resulting mixture vigorously until it thickens to the consistency of sour cream.
You need to seal the hole in the sheet as follows:
— wait for the surface to be repaired to dry completely;
— apply the prepared mixture to the damaged area;
- treat the damaged area with a solution of PVA and water (in a ratio of 1: 3);
— apply 2 more layers of repair mixture (the thickness of each layer is more than 1 mm);
To carry out such repairs, dry, but at the same time not sunny weather is necessary, since the asbestos in the prepared mixture must dry out on its own.
There are also ready-made mixtures for repairs, which include waterproofing materials. When using them, you must first clean the surface of debris and degrease it with acetone or solvent. Then you need to dry the surface.
The damaged surface is primed with a liquid solution of the repair mixture. After this, the mixture is applied using a spatula or a special gun. We wait 5-6 hours, cover with fiberglass and again put a layer of the mixture.
