Repair of a slate roof using bituminous mastic. Slate repair: how to fix holes and cracks

Slate roofs have not lost their popularity for many decades, due to their low cost, good performance, aesthetic appearance, simple installation that anyone can perform. In Europe today, the production of this type of coating, which is based on asbestos cement, is prohibited, but in Russia, slate continues to be produced, and the popularity of its use does not fall, despite the fact that there are other types of roofing material at a similar cost and with similar performance characteristics.

But the service life of such a coating is small, after ten to twelve years the roof becomes very fragile, easily breaks, becomes covered with cracks. All this negatively affects not only the appearance, but also the condition of the entire structure of the roof and the house. But it is not always possible in such cases to completely replace the entire coating; more often they carry out small repairs, the purpose of which is to close up a hole in the slate.

Before proceeding with such a repair, you need to make sure what exactly is the reason for the appearance of cracks and holes in order to avoid further destruction of the roofing.

Types of damage to slate and causes of occurrence

The slate has a sufficient service life, but over time and under the influence of weather conditions, it still breaks down. In general, there can be several causes of damage, among them improper installation, walking on the roof surface and many others. Consider the options for defects that may appear on the slate, and the reasons for their occurrence.

Often, with carelessness during transportation, small chips and cracks appear on the material, which can be invisible when laying sheets. Over time, such seemingly insignificant defects can cause serious damage to slate sheets, since this material is rather fragile. Therefore, when transporting sheets, it is necessary to strengthen them in full compliance with all requirements.

During installation, microcracks can also occur, which subsequently cause serious damage, often this requires changing the entire roof covering. These are cracks that appear when the nails are pressed too hard during installation. In this case, the material deteriorates over time more and more, at first invisible cracks gradually grow into holes, pieces of slate simply break off at the fasteners, which can cause them to fall to the ground.

Improper installation also causes cracks in the slate when the holes for the fasteners are not drilled correctly. According to the technology, the diameter of such holes should be larger than the diameter of the nail, but this rule is often neglected, long cracks and chips appear on the sheets.

Due to temperature changes in the ambient air, cracking of the sheet is also possible. What is the reason for this? Since slate perfectly absorbs moisture, then with a sharp cold snap to subzero temperatures, such a wet sheet loses its integrity, waterproofing properties, it becomes very fragile and brittle. The slightest blow will cause the leaf to simply crumble. Therefore, it is recommended to check the condition of the roof every spring, to replace damaged and unsuitable places for further operation.

The cause of damage to the slate, the appearance of holes and cracks on it can be mechanical impact, that is, walking on its surface while servicing the structures of the house. The slate is quite easy to break, so it is recommended to finish all work on the roof immediately during installation. It is very difficult to repair such holes in the slate in the future, therefore, it is not recommended to put mechanical stress on it.

Over time, moss and lichens often appear on the roof of such material, if they are not removed regularly, the surface will lose its previous qualities.

How to restore a slate coating?

There are various ways to close a hole in the slate covering, such repairs depend on the type of damage and its size. In total, there are three ways to repair such a roof covering:

A radical repair, which includes not only changing the entire roof covering, but also the rafter system. Usually, this type of repair is necessary in case of severe damage to the sheet and rafters, or if you want to completely change the roofing material to another, which requires a different design of the rafter system and lathing.
Partial replacement of slate sheets. This is done when the slate has very large chips, cracks and holes. In this case, the sheets are removed, and new ones are installed in their place. It is immediately necessary to check the integrity of the roof structures, the rest of the coating.
Redecoration, including the repair of holes and other small defects. This is usually done by applying patches from this material, sealing cracks with special compounds. The use of waterproofing in this case will extend the service life of the slate coating by about five years, but it is recommended to check its condition every year, carefully examining each sheet. After this period, the slate must be completely changed.

So how to close a hole or crack in the roofing material quickly? It is quite simple to do this, but first you need to completely clear the repair site from debris and moss, rinse it under a strong water jet. During the period of water drying, it is necessary to prepare a repair mixture of asbestos, cement M400 and ordinary PVA construction glue.

You can patch a slate roof with asbestos sheets.

Asbestos for the mixture can be bought ready-made, or you can simply grate it from an unnecessary slate piece on a grater. When working, you must use a respirator to protect yourself from the constant inhalation of asbestos particles, which is very harmful. The mixture itself is prepared in this way: you need to take two parts of the prepared cement, three parts of asbestos and a solution of water with PVA in a one-to-one ratio. Stir this mixture until the consistency of sour cream is obtained.

You can fill the hole with the prepared composition in this way: we apply our glue to the damaged area (it must dry completely before that!), Then we treat this area with a solution of water and PVA in a ratio of three parts of water to one glue. After such priming, we apply two more layers of the repair mixture, while the thickness of each should be more than one millimeter. Roof repairs should be done in dry but not sunny weather. The asbestos in this mixture should dry out on its own, gradually gaining strength.

There are also special, ready-made repair mixtures based on waterproofing materials. In this case, the hole can be repaired in this way: the damaged area is cleaned, wiped with a rag with gasoline, acetone or solvent to degrease the surface. In winter, a blowtorch or gas torch is used for drying to dry the place, in summer it dries up perfectly on its own.

The slate surface is primed with a liquid solution of the repair mixture (diluted with xylene, adding about five to ten percent of the total mass). After priming, the mixture is applied with a spatula or a special pistol, after five to six hours, we apply fiberglass to this layer, after which we again cover it with a layer of sealant.

It is quite easy to close up all the holes and cracks in the slate if you follow all the recommendations and rules. You should also carefully inspect not only the defective place, but also the entire surface, the rafter system, since rainwater that got into the hole could damage the tree, insulation, if any. Therefore, it is better to immediately identify and fix the problem than then completely block the roof.

Since the sixties of the last century, slate has become the main roofing material in our country. Cheapness, fast, simple installation allowed slate sheets to hold the leading position for more than a dozen years. Despite the fact that today slate is being replaced by metal and tile coverings, slate roofs are found in almost every settlement. Most often, the service life of such roofs is more than 10 years, which means that cracks and chips appear on the slate coating. It is recommended to replace heavily damaged slate sheets, but this article will tell you how to extend the life of a cracked sheet.

The reasons for the appearance of cracks on the slate are microcracks when branches or cones fall from trees, germination of moss and lichens, stagnant rainwater, installation errors (for example, using construction nails without a rubber backing or incorrect sheet cut), the severity of melting snow if it is untimely dumped from the roof ... You can tell if there are cracks in the slate roof by the smell of dampness or mold stains in the attic. The second method for detecting hidden cracks is a low dull sound when tapping with a rubber hammer on the sheet.

The most affordable and easy-to-use method for repairing chrysotile cement sheets is to cover it with a solution of sand and cement. This option is suitable for cracks and holes, regardless of their size.

The combination of bitumen mastic and roofing material allows you to quickly and without preliminary preparation cover up a crack or apply a repair patch on damage. A significant drawback is the likelihood of an increase in a crack or a split in a slate sheet when the bitumen is overheated.

The best option for filling narrow cracks is epoxy, which is poured just above the gap level. Epoxy compounds will cope quite well with a sheet of slate split in half. To do this, the two halves are connected with tape, the joint is degreased with gasoline and filled with epoxy.

Butyl-based self-adhesive tapes are an alternative to epoxy. This material is distinguished by elasticity, tightness, high adhesion, the ability to hold the wave of chrysotile cement sheet in the desired position. Butyl rubber tape removes the crack in just five minutes. The versatility of this type of self-adhesive allows you to use the material for repairing any surfaces. The disadvantages are the rather high cost and the required smoothness of the surface; therefore, it is recommended to pre-sand or paint over the surface with roughness.

A budgetary, but no less effective way to cover cracks is to use nitrocellulose glue. It is important that the adhesive is waterproof. The glue is divided in half, one part is diluted with acetone to a liquid state, the second is mixed with slate chips after cutting the sheet. The liquid part is applied to the crack in three to four layers. After drying, a mixture of glue and saw cut is laid on it, which is closed with construction tape.

No matter how beautiful the new roof looks, time is running inexorably. There comes a time when the real estate owner is faced with the question: how to seal the 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

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;
defects in the roofing device remaining after installation;
physical aging;
other flaws.

When the owner decides to cover the roof with slate, he knows what lies ahead. Heavy transport of material to the workplace. Low aesthetics of the material, its fragility, additional work on its refinement. But, the budget cost of the material, its versatility, overpowers - these are the indicators that made slate possible to become popular.

Experts advise: to use special antiseptics for long-term protection of the material from the appearance of lichen and moss. This design will increase the operating time.

Slate cannot be called the most technologically advanced material. But holes, chips, mother-in-law, any flaws can be repaired. Naturally, simple patches won't help. We'll have to allocate funds to eliminate the shortcomings. While the roof is new, it is advisable to immediately provide for the rules for cleaning the material, caring for it.

Preparatory work for repair

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. They imply the replacement of 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 the lathing and rafters is required. Partial repairs are performed when it is required to remove the old slate and put new sheets of material. For cosmetic repairs, flaws on the slate are patched up with certain compositions.

Crack bridging techniques

Filling a crack in a 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 cement it.

Repair mixture

Mixtures are made from water, asbestos, cement, PVA glue. It is simple to do: one part of the cement is covered with three parts of asbestos. 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 its long-term preservation. The defect is closed with the resulting mixture in two layers. The thickness of each should be at least one mm. There are ready-made compositions on sale in hardware stores. They are based on waterproofing materials. You can use such a 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 compound. 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 required parameters. The corners of the patch should be rounded. From the inside, it must be smeared with universal glue. Then, with a little effort, press it against 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 the prepared holes. But they should be located in new places.

Tip: construction foam is also an option for sealing defects in a slate sheet. And the most staid and affordable! If several layers of polyurethane foam are applied to the defect. Then after it has hardened and dried, it is cut 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 butyl rubber sealing tape is used as a patch. It is self-adhesive and has a double-sided work surface. A decorating material or non-woven fabric is located at its top. And there is an adhesive base, it is protected by a strip of paper. It is antiadhesive, or a polymer can be used for the same purpose. It is with such a strip that the damaged area is sealed. The top of the strip is dyed in your preferred color if desired.

There is also a simpler method for eliminating material flaws. A dense fabric should be alternately laid on the defective place, then it should be treated with nitro paint.

It is also fashionable to fix a crack in the slate right 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, become like rubber.

Safety engineering

Work on the repair of material on the roof, like any other, requires the indispensable observance of the rules for the preservation of a person. The person performing the work must wear appropriate special clothing. Non-slip shoes should be worn on your feet. The work is carried out in calm, not sunny weather, without rain or wind. If necessary, you need to invite another person. This is done to hedge against an accident.

How to repair a crack in the roof slate? Such a question can often be heard from summer residents, whose roof of a house is leaking, covered with slate for more than a decade. And to change, for various reasons, there is no way.

The appearance of cracks in the slate can be associated with both mechanical damage and improper installation and operation.

Slate defects and the reasons for their appearance

Good old gray wavy slate tested over the years. It would seem that he has no demolition. However, in reality it is far from the case. Cracks, chips, holes are usual for him. Repair? Yes, it is possible. But you need to clearly understand that patches will not save you for a long time. If only for a short time, while funds for radical repairs accumulate, but then the roof still needs to be changed. Alas, slate is not the most technologically advanced material. And you should start by identifying the reasons that contribute to the appearance of these very cracks. And there can be many such reasons.

natural "aging" of the material or its operation beyond the prescribed period;
non-compliance with the production process; liberties can be very diverse: for example, the norm of the cement laid in the solution is not observed, instead of long asbestos fibers, short ones are used, the terms for hardening of the sheet are not met, etc .;
a slate roof is based on an incorrectly selected slope angle;
violation of the manufacturer's requirements during the transportation of slate, mistakes in preparation for fastening work, during laying and installation;
using for fasteners not slate (with special rubber gaskets), but ordinary nails;
mechanical impact on slate.

Before starting repairs, the slate should be cleaned with a broom and water.

To know how to repair slate, you need to determine what type of work the planned work belongs to.

A radical (complete) renovation, which implies the replacement of the entire roofing system, namely: rafters, roof coverings. It is used when the slate sheets and rafters are seriously damaged or a person just wants to change the slate for a different roofing material, but it requires a completely different design of rafters and battens.
Partial renovation. Occurs when it is required to replace the old slate, dotted with cracks, chips and large holes, with new sheets.
Redecorating. In this case, small defects in slate are repaired with patches, special compounds, etc.

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Preparatory work and methods for sealing cracks

Let us dwell in more detail on the latter option and, in particular, on filling the cracks in the slate. There are simply a huge number of such methods.

But first about what unites them: this is the obligatory preparation of the surface for repair. And it consists in the following:

first with a broom, and then with water, dirt, litter, grass, foliage, moss, earth and other debris are removed;
the crack is degreased with acetone, gasoline or another solvent, then treated with a primer based on PVA glue;
the area to be repaired is filled with cement or other insulating mixture.

And now about the most common methods.

Slate repair mixture is made of cement, asbestos, PVA glue and water.

After preparatory work, it is necessary to make a repair mixture. It is done simply: 1 part of cement is poured into 3 parts of asbestos, where then water and PVA construction glue are added in equal proportions. Everything is thoroughly mixed until a thick consistency is formed. The resulting mixture in 2 layers should be filled with a hole or crack, and the thickness of each of them should be at least 1 mm.

It is necessary to repair slate roofs in dry weather, when there is no sunlight, thereby providing the opportunity for asbestos to gain maximum strength.

For long-term preservation of its qualities, the mixture should be prepared in small portions.

In addition, there are ready-made compounds based on waterproofing materials. In this case, the damaged area is cleaned of debris and degreased with acetone or gasoline.

Further, with the same composition, only with a more liquid (diluted xylene), it is first primed, then covered directly with it, and after 6 hours a glass cloth is applied to this layer, followed by another layer of sealant.

And aluminum foil is also used to repair cracked slate. A patch of the required size is cut out, the corners are rounded off. From the inside, it is coated with universal glue, after which, with a little effort, it is firmly pressed against the sheet, from which the old fasteners are first removed.

At the end of the process (patching), the slate is attached to the roof with nails through the holes made in it already in another place.

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A few more easy ways

Construction foam can be used to seal cracks in slate.

Also, a butyl rubber sealing tape is used as a patch. It is self-adhesive with a double-sided work surface. At the top, the tape is made of a decorating material or non-woven fabric, at the bottom the adhesive base is protected by an anti-adhesive strip of paper or polymer.

All you need is to remove this strip and seal the damaged area. And the upper part, if desired, can be painted in any color, the material allows it.

Another such method is the application of several layers to the crack at once. Polyurethane foam is blown into the hole on the prepared surface. After hardening, drying and cutting it along the contour of the wave (slate sheet), a layer of sealant is applied on top, and after a while (after drying) - another layer of bitumen resin.

It is good to use such a flaky cake when the slate roof is leaking. A simpler analogous method is to alternately lay dense fabric (almost any) and nitro paint.

Sometimes a crack in a slate can be repaired right on the roof without bothering to remove the material to the ground. In this case, the decisive role is played by the silicone paste. After preliminary procedures, the desired crack is first covered with slate crumbs, and later filled with silicone.

Along the edges of a small crack, holes up to 4 mm in diameter are drilled. She herself is filled with hot resin or special roofing sealants, which, when dry, become like rubber.

When carrying out repair work, especially on the roof, you should carefully observe safety precautions.

As you can see, the methods are not very complicated. And for repairing a slate roof with your own hands, you can safely use them.

However, if there are no primary skills or there is no elementary desire to tinker with slate, you can hire a specialist who will solve the problem quickly and efficiently.

Everything is suitable for repairing slate: cement, polyurethane foam, sealant, bituminous resin. But much more important are high-quality preparatory work, summer and dry weather. There is a sense in repairing only when the roof is leaking in a maximum of two or three places.

In case of large damage, you should not try to fix something, it is easier to replace the damaged sheets, and if such a procedure is impossible, it is better not to touch anything at all.

Despite the fact that roofing made of asbestos-cement sheets is durable after decades, external atmospheric and climatic factors affect the material. Something has to be replaced, something to patch up, somewhere to block. This is where the application of knowledge in the field of construction is required, and if you know how to repair a crack in the slate on the roof, then such work will not seem difficult.

Cosmetic repairs will help extend the operating life of the roof by up to 10 years. Therefore, the topic is especially relevant. In the past, the roof was sealed using oil paints and fabric strips. This technique was not famous for its particular effect, and the state of the overlap improved by only a couple of years. Today, modern materials are freely available that make the process of removing cracks and chips on the roof more efficient.

Simple roof reconstruction of a house

Roof leakage indicates damage to the integrity of the material. To get rid of such a problem, you can use one of the effective methods. Any of them is easy to apply in practice and not difficult, but here it is important to know how to repair a crack in the slate on the roof. In 90% of cases, installation of a patch or sealing of the affected section of the roof will be required.

Check out the options for action in the event of a roof leak, the easiest and fastest method to eliminate a leak, the slate patching technique. It is important to talk about such details in advance.

The most common technology for restoring damaged asbestos-cement sheets is the use of asbestos paste.

How to work with the material: application features

Using asbestos paste for filling cracks, take care of preliminary dismantling of the damaged roof fragment and lower it to the ground.

What is required to prepare the composition

The mixture consists of two components: asbestos and cement. This pasta is easy to make at home.

Components:

asbestos - 3 parts;
cement - 1 part;
water - 0.5 parts;
dispersion polyvinyl acetate glue - 0.5 parts.

Water and glue can be added as needed until the paste reaches a creamy consistency.

For cooking:

prepare a separate container;
pour out the required amount of asbestos and cement (proportion 3: 1);
mix the components thoroughly;
add water and dispersion adhesive;
stir the paste until a smooth, creamy consistency is achieved.

How to work with asbestos mixture

Knowing how to repair the crack in the roof slate, you can get to work. Try to use the prepared pasta immediately. During storage, the composition loses its properties. Therefore, prepare exactly as much grout as is required to repair the roof of the house.

Preparatory moment

Before gluing the roof, prepare the damaged area:

clean the slate from debris;
rinse the broken slate thoroughly and degrease it. Gasoline is suitable for such purposes;
if an ordinary crack has formed on the surface, glue a fiberglass tape (serpyanka) along the entire length, extending it by 5 cm to each side from the crack (vertically);
fill the voids and cracks with wet rubber or seal them. The fibrous material can be further treated with a hydrophobic composition.

Application of asbestos-cement paste

The composition is applied to the damaged area gradually, evenly distributing each of the layers over the surface. In this case, the total thickness of the applied paste must reach at least 2 mm. After the patch has dried, the seam must be sanded with sandpaper.

When restoring, try to paint over so that the coverage area extends beyond the crack. After repairing broken slate sheets, you don't have to worry about the roof leaking for the next 8-10 years.

Foil use

Asbestos paste is not the only option for treating roof damage. If you do not know how to repair a crack in the roof slate, use foil instead of paste, on which a little all-purpose glue is applied and applied to the damaged area from the wrong side. A snug fit of the patch is ensured by rounding the corners, so they are less bent. The bonding of the foil to the reconstructed surface is obtained firmly due to the used universal adhesive and reliably protects the inner space of the attic from the penetration of water and moisture.

If you need to close up the part of the roof where the fastener is located, then seal the crack with foil and drill a hole for the fasteners in the other part of the sheet.

After repair, the removed slate sheet is mounted in place. Do not forget about the use of special rubber pads under the nails in order to protect the corrugated board from damage during installation. After finishing the reconstruction, disguise the patch to match the tone of the roofing material. At this stage, work is carried out in dry weather, and when applying paint, use a brush or roller. It is better to apply several layers, proceeding to re-painting only after the first one has completely dried.

Some of the methods do not involve dismantling damaged products in the place where the slate burst. How to close the crack, if you need to climb up, read on. This work is done directly on the roof, and for this it is vital to provide insurance.

Silicone paste for roof repair

Often used for roof repairs. The product is characterized by increased adhesion to materials made of asbestos cement.

Getting started, the damaged area is prepared: it is cleaned of dust and small dirt crumbs, using a brush for cleaning metal products. To do this, use acetone or a special solvent.

Before sealing the crack, it is filled with crushed asbestos crumb, which is then filled with silicone glue for slate. Such restoration is not difficult to carry out, and the whole process takes a maximum of a day and ends at the stage of tinting the treated area to match the general style of the roof. At the same time, coloring plays not only an aesthetic role, but also gives the connection additional reliability. Coloring in this case is simply necessary. The top layer allows a multi-layer patch to be anchored, since asbestos-cement sheets are porous themselves.

Elimination of damage with mastic

It is important to remember that at the joints, slate sheets are treated with mastic with a special reinforcing filler with a wavy structure.

Bitumen is melted in a separate container, pre-crushing. Foam and impurities generated in the process are removed. The melting process takes place at temperatures above 200 ° C until the bitumen is completely dehydrated. The grout consists not only of bitumen, a filler is added to the composition, which is preheated to a temperature of 110 o C.

Hot mastic, using a spatula or other suitable tool, is applied to the surface prepared for repair.

Sometimes a kind of rubber slate paint is used to restore damaged sheets. The tool has increased adhesive and strength properties. This method of slate restoration is gaining popularity.

How to use polyurethane foam to seal cracks in slate

Using polyurethane foam for restoration, the slate is pre-cleaned and degreased. Foam is blown into the resulting crack, but a little free space is left for the sealant, which, after the foam hardens, is squeezed out in a dense layer over the foam. A bituminous mastic is applied on top of the patch formed, which helps to seal the crack in the slate and protect the attic from atmospheric precipitation.

Now you understand all the complexities of slate repair. How to fix holes and cracks - you know, you understand the details, but this is the main thing when carrying out restoration work with