Slate roofing has recently been popular due to its universal application. Durable and unpretentious material was available to most consumers. However, even strong asbestos fibers do not withstand mechanical loads, which caused the formation of small cracks that let water through. Despite the fact that slate is not subject to corrosion, as metal coatings, repair of such a roof still needs to be done. Therefore, many ask the question of how to repair slate.
Reasons for the destruction of the slate roof
Damage to fragile slate occurs in the following cases:
- Under the action of shock load or inaccurate movement on the roof.
- As a result of falling tree branches, microcracks are formed.
- On the surface of the slate, moss and lichen form, which contribute to the destruction of the roofing material.
- Temporary destruction, the process of which begins after 10 years of operation.
- In places of accumulation of rainwater, destruction of the material may occur. Such weak spots are most commonly seen around a chimney or attic window.
- If the slope of the slope does not correspond to the slate roof, then water stagnation can also be observed.
- Using ordinary nails without a rubber gasket to mount the slate can cause cracks.
- Transportation and storage according to inappropriate rules. The consequences of such a violation can only be revealed during operation.
- As a result of a sharp change in temperature, microcracks also form on the slate.
- If the fasteners do not fit the hole. The place for fastening should slightly exceed the dimensions of the nail, so that during its seasonal expansion the destruction of the slate does not occur.
- The rough surface of the slate is the reason for the constant accumulation of snow in winter. Under the influence of the first spring rays, the snow cover melts, as a result of which the water is directed downward. However, above the eaves, where the roof is always colder, the snow melts more slowly, and the flowing water freezes again. The resulting frost slowly destroys the roofing material.
It should be noted that the appearance of cracks is due not only to the influence of natural phenomena.
Incorrect manufacturing technology plays a large role in this process, while a violation can be detected at any stage:
- Some materials are taken in smaller quantities than required by the factory recipe.
- Use of short asbestos fibers.
- Treatment finished material that does not meet quality requirements.
- Deviations from the basic technological rules.
Slate defect detection method
It is quite difficult to visually detect cracks on a slate roof, which cannot be said about corrugated board. However, it is still necessary to control the operation process, therefore, during inspection slate roof it is necessary to pay attention to the following point.
One of the signs of roof damage is the smell of dampness in the attic. Minor cracks in the slate allow rainwater to enter the rafters and thermal insulation. As a result, the wooden truss system and insulation are saturated with moisture and begin to deteriorate. Therefore, it is time to repair the slate roof. To identify a defect in early stage, it is necessary to visit the attic after each rain, and check the condition of the roof.
Definition of "disease" by cracks in slate
The presence of cracks on protruding waves requires patching both above and below.
If cracks have formed in the lower waves, then the repair will be more difficult. The tightness of this place becomes impossible due to the constant accumulation of water.
The difficulty of repairing slate is affected by the direct location of the crack:
- The easiest way to see a crack is along the top wave, which is considered the most harmless. In this place, the water does not stagnate, so there should be no leaks. Repair work involves the use of galvanized iron and a special roofing tape. Iron must be bent in the shape of a wave and placed under the slate, and the crack is covered with tape from above.
- The most dangerous is the crack running in the lower wave. It is she who causes leaks. In this case, to solve the problem, how to close holes in the slate, you should stock up on sealant, patch and folded sheet galvanized.
- The most serious problems arise when a crack is found across the sheet. Over time, such a defect becomes wider and gradually passes to other waves.
How to repair cracks and holes in slate - roof repair rules
Before sealing a hole in the slate on the roof, it is necessary to carry out the surface preparation process. He means to clean the roof of debris, moss and lichens, and rinse it well with a stream of water under high pressure.
To resolve the issue of how to close a crack in the slate on the roof, you can familiarize yourself with several methods that involve the use available materials and novelties of the construction market.
Elimination of defects with sand and cement
For work, you will need dry cement and sand in a ratio of 1: 2. The components are mixed well and water is added to the desired consistency. The prepared solution is kneaded and cracks or holes are sealed with it. The repaired area is left until the solution is completely dry, then painted in the desired color.
Application of butyl rubber tape
Sometimes solving a problem than repairing a crack in slate helps to use special tape. The top material is made from nonwoven fabric which greatly facilitates the staining process.
The slate repair process in this case proceeds in the following order:
- The area to be repaired is degreased regular gasoline
- Remove the protective strip from the tape.
- With the adhesive side, apply the tape to the damaged area and glue it.
- The finished area is painted in a suitable color.
Repair with hot bitumen
Cracks can be repaired with sickle tape and molten bitumen. To do this, apply liquid bitumen to the damaged area, then glue the sickle tape and re-apply bitumen. To melt bitumen, you will need a fire, an old bucket and two bricks.
A fire is kindled and bricks are laid on the sides. They put a bucket with pieces of bitumen. During the melting process, you can add a little mining to the bitumen to make the solution more elastic. Such mastic can be used even at very low temperatures.
The use of bituminous mastic
By using bituminous mastic it is very easy for slate to repair cracks in the slate sheet. To do this, the surface is cleaned and covered with a primer layer. Next, with a spatula, a layer of mastic is applied. For better spreading of the mastic, you can add a little water, but it can be used undiluted. You can apply an indefinite number of layers, it is important that each layer dries well. Experienced craftsmen It is recommended to apply mastic in two layers with a thickness of at least 1 mm.
The use of putty from asbestos, cement and PVA
To prepare the putty, you need to take cement and asbestos in a ratio of 2: 3. You will also need a solution of PVA glue and water, which are taken in equal proportions. A mixture is prepared from all components and mixed. The solution should have the density of sour cream.
Putty must be applied to a previously cleaned and dried surface. Holes in the slate are filled with a mixture and treated with a solution prepared from 1 part of glue and 3 parts of water. Then two more layers of putty are applied.
Repair with putty
In the hardware store you can buy a ready-made mixture for puttying. These solutions contain waterproofing materials, therefore can be used to repair a slate roof.
The repair procedure involves the following steps:
- The surface is thoroughly cleaned.
- The repaired area is degreased with a solvent or acetone and left to dry.
- Apply a layer of liquid primer.
- Putty is applied over the primer using a special gun or a regular spatula, and left for 6 hours.
- After this time, the problem area is covered with fiberglass and another layer of putty is applied.
Application of foam and epoxy
Troubleshooting how to close holes in slate with foam and resin is as follows:
- The repair site is well cleaned and degreased.
- The crack is filled with mounting foam and left to dry for about a day.
- A sealant is applied over the foam and the area to be repaired is covered with epoxy.
Resin can be replaced liquid foam, but it is worth remembering that it collapses faster under the influence of sunlight.
Tin patches
The problem of how to close holes in the slate on the roof is relevant for many people. A defect in the form of large holes and cracks can be repaired with a tin patch. To do this, do the following:
- A patch is cut out of a piece of tin and rolled into a tube.
- Push it into the hole and make a hole in the middle.
- A bolt with a gasket is inserted into this hole and pressed.
- Existing gaps are filled with sealant.
Repairing cracks with drying oil and chalk
Drying oil and chalk are mixed well, the resulting mixture is applied to a previously cleaned surface. After drying, the repaired area is painted with oil paint.
Application of moisture resistant glue
The use of this method is possible only on a perfectly clean surface, therefore, before sticking the slate on the roof, it is well washed by rubbing it with a stiff brush. After drying, each defect is sealed with a piece of dense fabric soaked with moisture-resistant glue.
At the same time, it is important that the fabric extends 3-4 cm beyond the edges of the hole. Another layer of glue is applied over the patch. Then the sheet to be repaired is turned over and the hole is filled concrete mortar. On the slightly set concrete, another patch is applied and poured with glue for slate.
Fixing Slate Defects with Aluminum Foil
Using ordinary aluminum foil, you can also eliminate some defects on the slate.
To do this, perform the following actions:
- Remove the old fastener.
- Cut out the patch from the foil.
- Fix the foil in the desired area and press it with a self-tapping screw.
- If the repair was carried out on a colored roof, then the patch is painted in the same color.
Ways to protect a slate roof from further destruction
If visual inspection reveals defects in different places roof, the situation becomes quite complicated. Most often this happens as a result of errors made during the installation of roofing material. In this case, a simple repair can only temporarily solve the problem, so it is important to stop or minimize the destruction process.
To achieve this goal, you can use a strip of dense fabric, which is pre-impregnated with paint. The strip is covered with cracks formed on the slate.
You can fix the crack in another way: a hole is drilled in the crack and a self-tapping screw is screwed in. In this case, the hole is additionally sealed with roofing sealant, which will tighten the edges.
After graduation roofing works the owner of the house admires the almost finished building and does not think about how and when he will repair the slate on the roof. It seems that this material is so strong that it will withstand all temperature fluctuations and any amount of precipitation. But that's not the case...
Why is it necessary to repair a slate roof?
Under the slate modern construction several types of materials are implied to protect the structure from precipitation. There is even a natural layered material of natural origin, but it is practically not used in the construction of modern buildings. Most often, wavy or asbestos cement fibers are used to cover the roof. Sometimes polyacrylic or jute fibers are used instead of asbestos. These fillers make the sheets lighter. And products made of bitumen are usually called euroslate.
Years fly by very quickly, and after 10–15 years, chips and cracks form on the roofing. Much more annoying when the roof starts to leak before the end of the warranty period. venturing self repair slate roofs, you should understand the causes of cracks and chips. This must be done to prevent further damage. The main reasons for the rapid aging of the material should be sought, first of all, in poor-quality manufacturing and violations of the technological process cycle by manufacturers.
More often than not, the consumer cannot correct such imperfections as lack of cement, incorrectly sized asbestos fibers, and poor-quality completion of finished sheets. Also, very often, manufacturers put on sale fragile sheets with a broken hardening period. Sometimes consumers themselves make critical mistakes when performing installation work. For example, incorrect laying of sheets, incorrect choice of roof slope and fastening of products without special gaskets under the caps.
If the amount of damage is very large, and it is clear that it is impossible to repair individual cracks and chips, it is necessary to replace the old slate with a new roofing. Work should begin with the dismantling of the broken by time asbestos-cement sheets. During this work, it is necessary not only to remove the nails and lower all parts of the damaged slate to the ground, but also to carefully examine the entire truss system structures. Since a fungus could start from leaks or rotting of wood could begin..
If rotten elements of the roof frame are found, they should be replaced. The entire truss system must be re-treated with antiseptics and a new roofing laid.
There is not always money and energy to work on replacing defective slate on the roof. Therefore, you should look for alternative ways restoration of the tightness of the roofing material. To extend the life of the slate coating and restore its functionality, there are several completely real ways. As a rule, this is the manufacture and application of a patch on a crack or the usual coating with a sealant. Below are a few step-by-step explanations on how to repair slate yourself.
Slate roof repair with asbestos paste
Such repairs are made using a special paste, consider this method.
How to repair a slate roof with asbestos paste - a step by step diagram
Step 1: Prepare the Ingredients
It is advisable to first remove the product from the roof. For liquidation small crack in this slate sheet, you can independently and quickly make a thin asbestos paste. The mixture for the manufacture of such a paste consists of asbestos fiber, cement, PVA glue and water. After mixing cement with asbestos in a ratio of 1: 3 in a container, water and PVA glue should be added in equal amounts. The consistency of the composition obtained after stirring should resemble the density of high-quality sour cream.
Step 2: Apply the mixture
Cracks are carefully caulked, the fibrous material can be pre-treated with hydrophobic compounds. Then this place is covered with a creamy asbestos-cement paste. After complete drying, for greater aesthetics, you can walk sandpaper along the resulting seam, just do not overdo it so as not to open it again. A roof repaired in this way will protect the home from moisture penetration for about 5–10 years.
How to repair a slate roof with foil?
The patch on the roof can be applied quickly and easily with aluminum foil, which you can even take from a chocolate bar. When the damaged element is dismantled and cleaned, wrong side A specially selected adhesive is applied in a thin layer of foil, which can glue aluminum to a slate sheet. The corners of the patch should be rounded off to prevent curling. If such a patch is needed at the place where the sheet is attached to the roof, then, having closed this damage with foil, scroll a hole for fastening in another part of the slate surface.
Now we install the element back, do not forget, just like during the initial installation, use a rubber gasket under the slate nail. At the end of the work, it is necessary to disguise the patch in the color of the entire roof surface. Paint should be applied when comfortable temperature in dry weather. It is best to paint over the patch in the traditional way - with a roller or brush. For the best effect, two approaches should be made, and after the first layer, the repaired area must be thoroughly dried.
How to repair slate without dismantling?
It was more convenient to carry out all the previous methods on the removed sheet, but there are tricks for those cases when the sheet is not dismantled. Let's try to eliminate the defect without removing the slate from the installation site. We provide ourselves with insurance and climb onto the roof. The damaged area should be thoroughly cleaned of dust and small pieces of asbestos. wire brush. You can degrease the repaired surface with acetone, gasoline or a special solvent. Pour slate chips into the gap and evenly distribute it throughout the crack.
Now you can pour silicone paste on the surface of the crumbs and let it grab, and then paint over the entire roof with paint to match. Such slate roof repair takes less time and is quite reliable. Roof sections with a painted surface should be painted over immediately after the silicone paste has set, since asbestos-cement sheets have a porous structure, and the edge of the repaired surface will quickly become dirty.
Puzzled by the question of how to repair a slate roof, one can recall another way to seal cracks - foam. After cleaning and degreasing, a kind of cake is created at the site of damage. At first, the crack is not completely blown out with mounting foam. After drying the repair site, cut off the excess foam on the sides with a sharp knife and apply a layer of sealant of the same thickness. The most effective option for waterproofing will be the use of a waterproof composition. Such a slate protection material has good adhesion and therefore adheres tightly to the surface.
To complete, coat the resulting surface with bituminous resin. To keep the resin in a liquid state, a little diesel fuel should be added to the heated mass. It turns out a primer, in which ordinary clean sand can be added for density. This method of repairing damage will reliably protect the roof from leaks on long time, although it will make you work hard and even, probably, get dirty quite well.
No matter how beautiful the new roof looks, time runs inexorably. There comes a time when the owner of the property faces the question: how to repair cracks in the slate on the roof? There are many solutions to this question! The choice is up to the owner, only he can extend the operation of the slate roof.
In this article
Slate roof defects
The list of slate defects that may appear during the operation of the roof:
- the appearance of cracks in the slate;
- overgrowing of material with moss;
- mechanical damage;
- roofing defects remaining after installation;
- physical aging;
- other flaws.
When the owner decides to cover the roof with slate, he knows what lies ahead for him. Heavy transport of material to the workplace. Low aesthetics of the material, its fragility, extra work for its beautification. But, the budget cost of the material overpowers, its versatility - it was these indicators that made it possible for slate to become popular.
Experts advise: in order to permanently protect the material from the appearance of lichen, moss, use special antiseptics. This design will increase the operating time.
Slate cannot be called the most technologically advanced material. But holes, chips, cracks, any flaws can be repaired. Naturally, simple patches will not save. We will have to allocate funds to eliminate deficiencies. While the roof is new, it is advisable to immediately provide for the rules for cleaning the material and caring for it.
Preparatory work for repairs
Before making repairs, the slate must be cleaned with a broom with water. Remove all foreign objects, dirt, debris, earth. After cleaning, determine what type of repair is required. It can be radical, that is, complete. According to them, they mean replacing the entire system: rafters and coatings. This type of work is used when the sheets of material and rafters are badly damaged.
Then a different design of the crate and rafters is required. Partial repairs are carried out when it is required to remove the old slate and lay new sheets of material. At cosmetic repairs flaws on the slate are closed with patches, certain compositions.
Crack Filling Methods
Sealing a crack in slate is the most common work option. There are many solutions to the issue. If a crack is found on the sheet, it and the place around it must be degreased with gasoline, acetone, solvent. Then the place should be treated with a primer with a base of PVA glue. Fill it with an insulating mixture, you can use a cement composition.
Repair mixture
Mixtures are made from water, asbestos, cement, PVA glue. To do it is simple: three parts of asbestos are poured into one part of cement. PVA building glue and water are added to this composition in equal amounts. Then everything is gently mixed until a mixture with a thick consistency is formed.
The mixture is made in small portions! This is done for 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 there are already ready-made compositions on sale. They are based on waterproofing materials. You can use this composition, but preliminary degreasing of the material before repair is always performed.
You can work with the same composition, but only diluted xylene. The place of the defect is first covered with a primer, then covered with a composition. As soon as six hours have passed, it is necessary to put fiberglass on this layer. And, reapply a layer of sealant.
Application of aluminum foil
To perform the work, prepare a patch with the necessary parameters. The corners of the patch should be rounded off. From the inside, it must be smeared with universal glue. Then, with a little effort, press against the slate sheet, from which the old fasteners have already been removed. After applying the patch, a sheet of material is attached to the roof with nails. This must be done through the prepared holes. But they must be located in new places.
Advice: construction foam- also an option for sealing defects in a slate sheet. And the most affordable and affordable! If several layers are applied to the defect polyurethane foam. Then after it hardens and dries, it is cut off along the contour of the wave of the material, and a layer of sealant is applied on top. Then this place is dried, and a layer of bitumen resin is applied.
Sometimes a sealing butyl rubber tape is used as a patch. It is self-adhesive and double sided. work surface. On its top is a 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 dyed in the preferred color if desired.
Is there some more simplest method to eliminate the defect of the material. On the defective place should be alternately laid dense fabric, then it should be treated with nitro paint.
It is also fashionable to eliminate a crack in the slate directly on the roof without removing the sheet. Then you need to use silicone paste. First, the crack is covered 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
Work on the repair of material on the roof, like any other, requires indispensable compliance with the rules for the preservation of man. The person performing the work must have appropriate special clothing. Non-slip shoes must be worn on the feet. Work is carried out in quiet, not sunny weather, without rain and wind. If necessary, you need to invite another person. This is done to protect against an accident.
Slate - the material for roofing is quite good and practical. And relatively inexpensive, in comparison with other, more modern and stylish coatings. But he has one good minus; he's too fragile. Especially after some time has passed. As the slate on the roof ages, cracks and holes appear in it. In order to avoid these troubles, it is necessary, at least once every six months (in the spring, after the snow melts and in the fall, after the leaves from the trees fly around), to clean the roof with a broom or brush. It is even more necessary if trees grow near the building. If this is not done, fallen leaves, needles and small branches from trees rot on the cover, and there it appears and begins to spread green moss and fungus, as a result of which the slate decays and cracks and holes form on it.
By following these simple steps, you will significantly extend the life of this coating. However, sooner or later, cracks in the slate will still appear. And here I want to advise one of the ways how to eliminate a crack, or a small hole in a slate sheet, if it is not possible to replace it.
It will take
- Gasoline (I used AI-92 brand).
- Styrofoam.
- Small nylon mesh (glass cloth can be used).
- Brush.
- Scissors.
- Solvent.
- Rag.
- Hard brush.
Cooking glue
To begin with, let's prepare our homemade glue without forgetting the precautions; make sure that there is no open fire nearby, because we will work with gasoline! And try not to inhale gasoline vapors - this can affect your well-being not in better side!More convenient work it will do, in my opinion, if the glue is in some kind of dish, with a wide neck, like a plastic mayonnaise bucket. So, let's pour two hundred and fifty milligrams of gasoline into a measuring cup (the higher its octane number, the easier and faster the foam will dissolve in it) and pour it into a bucket.
I used 92 gasoline, but since it is quite stale (I drained it from an old motorcycle), and probably ran out of gas, I had to splash another fifty milligrams of 646 grade thinner into it.
If you are using fresh gasoline 92nd or 95th, it is not necessary to pour solvent into it - it will do an excellent job with the foam. Now we break the foam into pieces of suitable size, and send it to a bucket of gasoline. The foam is dissolved there almost instantly, effectively hissing and bubbling.
We continue to dissolve the pieces of foam until the resulting glue acquires a gray consistency, similar to organic wallpaper paste; the same viscous and thick enough to stay on the brush and, later, on the nylon mesh.
Next, put everything you need in a bag; a bucket with freshly prepared glue, a nylon mesh, scissors, a brush, a solvent, a rag and climb onto the roof, to a damaged place on the slate, not forgetting, again, about precautions.
We repair slate
Now it is necessary to clean the place of gluing (fields, five centimeters from the edges of the crack) with a stiff brush, from debris, dust and sand. Next, we moisten the cloth with a solvent and wipe the places cleaned with a brush where the glue will lie.
On the treated edges of the crack, apply a layer of glue with a brush.
We lay a nylon mesh on a crack with glued edges. Top it all off with glue.
Now you need to wait two to three hours for the glue to dry a little. Yes, and catch your breath during this time from gasoline vapors! After the indicated time, we rise back, apply a fresh layer of glue to the slightly dried glue and lay the mesh with the second layer in order to fix the result, so to speak. And now on top again, thoroughly, and not sparing the glue, we apply the last layer of glue. Styrofoam dissolved in gasoline will tightly cling to the slate, so that no bad weather will tear it off and wash it away! It is possible, if desired, until it starts to dry out, sprinkle the whole thing on top with dry cement so that the repaired section of the roof is not conspicuous if it is in a conspicuous place. This completes our work. The rest is a matter of time. Seven to nine hours will be enough to weather the gasoline vapors from the adhesive and further harden it. Do not forget to find out the weather forecast for the next day before starting work, since excessive moisture will obviously not benefit such work. Such repairs will extend the life of the slate by at least another couple of years. Well, or until it becomes possible to change the old coating to a new one.
The mass use of slate in previous years was determined by its affordable price and durability. There are still many houses covered with this popular roofing material, not requiring special care. But minor repairs you still have to do it, because over time, cracks and even holes appear on the surface. Those who by different reasons cannot part with the cement-asbestos coating, they make repairs with improvised materials. Let's see how this works out in practice.
Why cracks appear
With all the remarkable advantages, slate retains a low resistance to mechanical stress. Although the coating tolerates solar ultraviolet and high moisture quite well, their prolonged exposure weakens the original strength. Over time, the structure of the material becomes more vulnerable, and with sudden changes in temperature or when branches fall, longitudinal or transverse cracks appear in the sheets. Affects and wind load, the pressure of winter layers of snow, which is why the strong crest of the wave begins to sag, exposing the heads of the nails. If you do not close up the defects that have appeared, then they will gradually expand.
Of course, it is better to completely replace the damaged coating. But if this is not possible, then minor repairs become the only way to eliminate leaks and protect the building from destructive moisture.
Care prolongs the life of the roof
In addition to knowing the process of repairing a slate roof, you need to understand how not to bring the roof to a deplorable state. Even inaccurate movement on the roof when cleaning the pipe and repair work ah can lead to the appearance of new cracks under the weight of the master. Therefore, it is necessary to lay special wooden flooring on the coating so that the transverse slats that fasten the boards from below are located in the recess of the slate wave. This allows you to evenly distribute the load over the entire coverage area. On steep roof slopes for work, there should be a ladder-ladder, having a length equal to the full slope of the roof, with a hook for the ridge.
Chronic disease of slate roofs - colonies of mosses and lichens, especially in shady places. If the vegetation has already taken over the depression of the wave, it will block the flow of water, and the growing moss will begin to lift the joints of the sheets, opening the way for rain moisture. Any vegetation on slate creates conditions for the formation of new cracks.
simple and effective method fight against mosses and lichens - regular painting of the rough surface of slate with several layers of resistant atmospheric paint. Cleaning the old roof from the green carpet can be done mechanically, and then treated with a preparation that destroys the root system of the colony.
Inspection should be done at least twice a year roofing from the attic side. In the presence of an insulating subroofing layer, it is more difficult to detect cracks, but it is necessary to carry out an audit. Otherwise, spots of mold will soon appear in the places of leaks, which will pass to wooden structures.
How to seal cracks
Longitudinal cracks along the crest or deepening of a wave can be repaired with a waterproofing self-adhesive butyl rubber tape specially designed for slate. Install it from the outside and inside cracks or just outside. If you install the tape only from above, then it is better to install a strip of galvanized sheet under it, which should be shaped in advance in a wave shape. Then the movement of the crack will not affect the integrity of the tape.
The outer side of the tape is usually covered with a non-woven fabric, which, if desired, can be dyed in the desired color. It is not difficult to stick the tape on the slate if it is well cleaned and degreased. Tape piece desired length put on the crack from one edge, and gradually remove protective film from the inside of the material while pressing it against the damaged part. Check the adhesion of the tape to the roofing material so that there is no partial peeling off of the edges.
We use bituminous mastic
To repair longitudinal cracks, you can use a fiberglass serpentine mesh or fiberglass, which is best glued using cold-curing bituminous mastic. Transverse cracks are usually sealed with the same sickle mesh, but sometimes you still have to completely change the damaged sheet. To do this, you have to remove several adjacent sheets in order to remove the damaged one, and then put everything back and securely fasten it.
Cracks found in the sheets of the cornice row of the coating are more difficult to repair, so they are most often replaced with new ones. With such a replacement, careful removal of the nails connecting the cornice and the second row of the roof is required, since even whole sheets of old slate can crack if not installed carefully.
If for some reason it is not possible to replace the sheets along the eaves line, then they will have to be removed, and the cracks should be glued with a fiberglass mesh on bituminous mastic, applying materials from the upper and lower sides of the cracked slate. Then the repaired sheets must be reinstalled. Leaving damaged sheets is not recommended - cracks and chips will inevitably expand over time.
This material can also be used to repair holes or wide cracks, additionally using fiberglass. For reliability from the side of the attic, it is necessary to press a galvanized sheet with a wave bend to such damage, which can be removed after the cement mortar has completely solidified. withered cement mortar can be primed and painted with weatherproof paint.
To make traces of repair work invisible, you can paint the entire surface of the slate coating with a single color. Then your roof will serve you for many more years.
