Laying slate on a roof is not particularly difficult if you first familiarize yourself with the work technology and prepare the necessary tools and fasteners.

Main characteristics of slate

Despite the emergence of new roofing materials, the popularity of traditional asbestos-cement slate remains quite high. This is explained by the affordable cost of the material, the ability to install the roofing with your own hands, without the use of specialized tools. Classic slate is suitable for simple single-pitched and double-pitched roofs; it can be used to cover a hipped or hipped roof.

Slate is highly resistant to static loads, resistant to aggressive environments, and is easy to process. The disadvantages include the rather large weight of the material - when installing it yourself, you need to attract one or two assistants to lift the slate sheets onto the roof without the risk of damaging them.

When considering the question of how to cover a roof with slate, it should be noted that this material is best used for laying on roofs with simple geometry. It is best if the roof has a slope of up to 20° or more than 35°, since in this case the likelihood of snow accumulation in winter is reduced.

The technology for laying covering on a pitched roof involves the installation of slate sheets that comply with GOST 30340-95. It could be slate:

• six-wave (sheet thickness 5/6/7 mm, width 1125 mm);
• seven-wave (sheet thickness 5 – 8 mm, width 980 mm);
• eight-wave (sheet thickness 5 – 8 mm, width 1130 mm).

The length of any type of slate sheet is 1750 mm.

When choosing slate, you need to pay attention to its markings, which indicate the height and pitch of the wave. The arrangement of sheets of material on the roof should be developed taking into account these parameters. The wider the wave pitch, the larger the area of ​​material spent on vertical overlap. Selecting slate and the method of laying it is based on the size and configuration of the roof slopes.

When determining how to cover a roof with slate, you need to take into account the drainage system. If the gutter for collecting precipitation is supposed to be located under the roof overhang, it is enough to lay the outermost row with an overhang of 200-250 mm relative to the wall of the building. If water from the roof will drain directly onto the ground, the overhang should be at least 400 mm.

Slate rafter system

Before you install the roofing yourself, you should make sure that the rafter system is suitable for laying slate. This material belongs to the heavy category, so the roof frame design must be designed for high loads, which include:

• total weight of the roofing pie;
• atmospheric loads;
• the weight of people installing, maintaining or repairing the roof.

If the roof is designed for metal tiles, ondulin or other lightweight materials, it may be necessary to reduce the installation pitch of the rafter legs or use struts to increase the rigidity of the wooden trusses. Particular attention should be paid to the roof frame if slate is intended to be used to cover an old soft roof.

The minimum cross-section of rafters for a slate roof is 50×180 mm, the sheathing is made of 60×60 mm bars or unedged boards 15-25 mm thick. The pitch of the board sheathing should be 200 - 1000 mm. When using sheathing made of bars, it should be taken into account that each sheet must be supported by at least three horizontal jumpers. A 60×120 m beam or a 60×150 mm board is mounted in the ridge part.

To properly lay slate, the sheathing must be made of dry lumber that does not have deformations.

If you plan to install a chimney or exhaust pipe on the roof, you need to make a special sheathing for the structures before laying the roofing. The arrangement of the drainage system should be completed before laying the roofing. On the bottom row of the sheathing it is necessary to fill a strip of metal about 300 mm wide and 2-3 mm thick, which will prevent the destruction of the lower edge of the roof under load. The metal strip should be waterproofed on both sides, and holes should be made for roofing fasteners.

How to cover a roof with slate?

If you are going to install a slate covering with your own hands for the first time, you should know that this material allows you to attach no more than two layers at one point. Thus, the installation scheme should be well thought out at the roof design stage.

The sheets must be mounted with a horizontal overlap in one or two waves. A single wave overlap is most often used if it is necessary to cover a fairly steep slope with a small snow load. An overlap of two waves is required for flat slopes; this design is much more reliable, but the total cost of the coating with such installation increases, especially with a large wave pitch. Vertically, the top sheet must overlap the bottom sheet by at least 200 mm.

The installation technology requires starting installation from one of the lower corners of the slope and continuing along the eaves overhang. The slate should be laid taking into account the wind rose: the overlap should be located on the leeward side. It is recommended to lay the first row of sheets along a pre-tensioned rope so that the overhang is neat and even. To avoid combining more than two layers of slate at one point, various installation options are used. The most popular methods are staggered installation (with offset) and without offset.

The staggered installation is popular due to its simplicity. In this case, the new row is laid with an offset relative to the bottom one. Thanks to this, it is possible to avoid the overlap of waves and no more than two sheets of slate are joined at any point. When installing with offset, it is necessary to trim the outer sheets and trim the top edge of the last row on the roof slope.

Staggered laying is ideal for installing eight-wave slate - just offset in four waves and use halves of cut sheets to start each odd row. The offset lines in this installation option are arranged aesthetically, in a checkerboard pattern.

If you lay slate without displacement, you can save roofing material, but this is a more labor-intensive option, which should be taken into account when starting installation yourself. In this case, it is necessary to trim the corners to the width of the wave and 120-140 mm in height. To lay the covering elements from left to right, the lower corner of each sheet of the top row is trimmed from the side covering the previous slate sheet of the horizontal row.

The question of how to cover a roof with slate is directly related to the choice of fasteners and the method of their installation. Slate nails, self-tapping screws and self-tapping screws are characterized by an enlarged head and are installed using a special rubber gasket, which ensures the tightness of the fastening point. The fasteners should not be driven in or screwed in all the way.

To avoid damage to slate sheets during installation, it is recommended to mark and drill holes in them for fasteners in advance. The holes should have a diameter 2-3 mm larger than the diameter of the nail or screw.

The slate is attached to the roof only at the crest of the wave. The first attachment point is located in the lower part in the second (overlapping) wave with a distance of 120-150 mm from the edge. The second attachment point is diagonally from the first, and the attachment at the top in the second wave is carried out after laying the overlapping slate roofing sheet.

After installing the covering with your own hands, you should install special ridge elements made of asbestos cement, arrange all abutments and joints, ensuring reliable waterproofing.

Safety rules and maintaining the integrity of slate

When working on the roof, not only installation technology must be observed, but also safety precautions. It is necessary to use safety cables and ropes. If the height of the building exceeds 6 meters, fencing should be provided. To carefully lift the slate sheet, it is recommended to use a nylon cable and a pulley system. If you need to cover a low building, assistants can supply the material.

Walk on the installed surface carefully. In order to freely walk on a slate roof during its repair or maintenance, it is necessary to install wooden ladders to distribute the load.

Compliance with safety precautions implies the use of protective equipment when working with asbestos-cement material: when drilling and cutting slate sheets, use a respirator correctly to protect the respiratory tract from harmful dust.

Despite the active spread of the latest roofing materials, slate remains popular due to its ease of installation and low cost. By following our instructions, you can cover the roof with slate yourself or control the quality of work performed by a contractor.

Slate selection

There are several types of slate: natural slate, polycarbonate, bitumen, but today we will talk about the most popular - corrugated asbestos-cement. This roofing material is available in several formats, which differ in size and thickness. Complete information on the characteristics of slate and additional parts for slate roofing can be found in GOST 30340-95.

A slate sheet can have from six to eight waves. The waveform is defined as a module - part of the marking of the form 40/150, that is, height / width. Of all the formats, six-wall slate is the thickest - 6 and 7.5 mm, the wave has a module of 54/200, the sheet width is 1125 mm, that is, one of the waves in the sheet is incompletely covering. The seven- and eight-wave sheets have a thickness of 5.8 mm and a width of 980 mm and 1130 mm, respectively. Thus, six- and eight-wave slates are almost equivalent in terms of format, but the first is almost twice as heavy. The standard length of slate produced according to GOST is 1250 mm, but large-format sheets up to 2.5 m long are also available.

The overwhelming majority of slate is produced in the form of untreated sheets, which is associated with the main disadvantage of this coating - overgrowth with moss and darkening due to the accumulation of dust in the pores. Painted slate does not have such a flaw, but it is somewhat more expensive. However, you can apply the protective coating yourself: clean the slate with a wire brush, sweep it away from dust and open it with pentaphthalic primer PF-020 or PF-010M. If you want to add color to the coating, apply universal alkyd enamel PF-115 as a second layer. The protective coating on slate not only performs an aesthetic function, but also increases the hydrophobicity and service life of the roof.

Installation of sheathing

Roofs of completely different configurations can be covered with slate - from ordinary gable roofs to hip roofs, including those with internal slopes. The supporting system is traditionally formed by rafter legs, to which a horizontal sheathing is nailed for attaching slate sheets.

For sheathing, you can even use an unedged board, but it must be of the same thickness - at least 25 mm, the permissible width is from 100 mm. The sheathing pitch is determined by the length of the sheets used. The first bottom board is nailed flush with the bottom edge of the rafter. All subsequent ones - with the expectation that each sheet of slate is attached along three lines: 100-150 mm from the bottom and top edges, as well as in the middle. Thus, taking into account the slate overhang of 50-100 mm above the rafters, the first two boards are placed with an interaxial distance of about 40 cm, the rest - 50 cm each. In this case, the third board should be positioned so that the sheet protrudes above it by about 50 mm. When the main elements of the sheathing to which the slate will be attached are nailed, the gaps between them are filled with second-grade lumber, which acts as a support for the slate for a more even distribution of loads.

Fastening the sheathing to the rafters should not be done with self-tapping screws; it is much more correct to use nails from 100 mm for this purpose, even better if the nails are rough. Slate is very sensitive to the curvature of the sheathing, so before final fastening it will not be superfluous to tighten the cord and level the boards into a common plane, placing wooden chips or scraps of roofing material under them. On the convergence lines of the slopes, where the skates will subsequently be installed, it is necessary to nail embedded boards to attach the protective pads.

Roof waterproofing

Slate roofing requires mandatory waterproofing to protect against leaks when the snow cover melts or in case of destruction of the coating. This part of the roof can have two implementations depending on the presence of insulation.

For uninsulated roofs, it is customary to use roofing felt, euroroofing felt or glass insulation in one layer. Installation of waterproofing is carried out in a horizontal direction from bottom to top. Each canvas is attached to the sheathing with special buttons, which are called roofing felt. The upper webs cover the lower ones with an overlap of 100-120 mm, while the fold is heated and pressed to form a tight, airtight connection. On skates, the waterproofing is cut along the convergence line of the slopes, then one solid sheet is laid on top, which is also soldered to the underlying layer. In the same way, the waterproofing contour in the valleys is closed.

If a protection belt in the form of mineral wool is placed in the rafter system, waterproofing is performed with superdiffusion membranes. The procedure for their installation is similar to “cold” waterproofing, with the only difference being that the overlap is made according to special markings on the edge of the rolled material. In addition, sealing between the sheets is not performed; waterproofing is attached only in the upper part, then the fasteners are covered with the top layer. A mandatory requirement when laying superdiffusion membranes is their correct orientation: the side on which the fleecy cover is present must face up.

Laying slate covering

Installation of slate can be done in two ways. On slopes where the width significantly exceeds the height, the sheets are laid staggered with an offset of 2-4 waves relative to the previous row. This placement helps avoid the formation of four layers of slate at cross joints, which occurs when laying without offset.

Nevertheless, direct placement of sheets also has a right to life; this method is optimal for covering high slopes of small width. In this case, before installing the adjacent sheet in the row, it is necessary to trim the corner on the bottom sheet to the width of the covering wave and the height of the overlap between the rows. The same is done when installing the top row: the corner of the bottom sheet is cut in the opposite direction, due to which there are no areas with four-layer overlap left in the coating.

The first row of slate is aligned horizontally, for which a mooring cord is pulled along the bottom line. Each sheet has nine attachment points, three in each line. The extreme points should be located no closer than the second wave from the edge of the sheet. The slate is fastened with special nails, the heads of which are protected by an aluminum or plastic cover. The nail is installed at the very top point of the wave, then the slate is pierced with one sharp blow and the nail is driven into the sheathing until the head is pressed tightly against the covering. The nails cannot be bent on the reverse side, but can be cut with a grinder, leaving “stumps” of 5-7 mm.

Installing a slate roof is a dangerous job; the height factor is aggravated by the significant weight of the materials. Therefore, work must be carried out with a safety rope, which is thrown over the roof and tied to a stationary object on the back side of the building. It is most convenient to lift slate onto the roof along two parallel pipes as guides, picking up the sheet from below with a hook on a rope. A not entirely obvious danger factor is the dust generated during cutting, so slate processing should only be carried out with a respirator and safety glasses. It is the asbestos dust generated during cutting that causes the notorious danger of asbestos-cement slate, but when the coating is fixed to the roof, it is absolutely harmless.

Construction and protection of junctions

It is somewhat difficult to reduce the coverage on the convergence lines of the slopes - ridges and valleys. The top ridge is cut quite simply: a horizontal cord is pulled, along which a cutting line is applied to the slate at the fitting site. You can do the same on inclined skates; it is only important to calculate in advance the height of the coating above the waterproofing. In such cases, one of the sides of the junction is cut along the cord, the other side is marked with a pencil from the back along the profile of the already laid coating.

In valleys there is no way to try on slate in place, so proceed as follows:

1. The overlap line is marked on the outermost solid sheet;
2. From the marking, the distance to the center of the valley in the lower and upper parts is measured.
3. The obtained values ​​are transferred to a sheet of slate and cut diagonally, making an indent of 20-30 mm.

GOST 30340-95 provides for the production of special products from asbestos cement to protect junctions: lower and covering elements of ridges, tray parts for valleys and corner strips to protect wind overhangs. However, these products are extremely rare, so the ridges and valleys of slate roofs are covered with protective elements made of roofing iron with galvanized or polymer coating, and the wind overhangs are covered with boxes made of boards.

Houses covered with ordinary gray slate can be found everywhere. At one time, this material was used as roofing in both expensive cottages and small private houses. This is due to its high performance, long service life and low price.

A roof made of slate can be painted in bright colors, and in this case its decorative properties are comparable to the most modern finishing materials. It is also important that it is quite possible to fasten the slate with your own hands and, of course, you need to know how to do it correctly. Interestingly, slate can be laid in different ways.

Properties of wave slate

Wave slate is a sheet of wave-shaped profile made from a mixture of asbestos and cement. There are from six to eight waves on the surface of one product unit. Asbestos acts as a reinforcing component and gives mechanical strength to the product.

Slate sheets can withstand weights of up to two hundred kilograms, so you can walk on them without fear when laying them. In addition, the material can withstand up to fifty defrosting cycles without loss of performance, and this parameter determines its service life. The following properties of wave slate highlight its advantages:

• Fire safety;
• resistance to aggressive environmental influences;
• good thermal insulation qualities;
• excellent noise-absorbing properties;
• ease of installation;
• low price.

The negative qualities of this material include low resistance to point impact loads and breaking force. A stone thrown into a roof can make a hole in the roofing; in addition, due to the porous structure of the material, lichen and moss can settle on it.

Asbestos in the composition of slate sheets is in a bound state, and the release of its fine particles in the form of dust into the environment can be negated by impregnation with drying oil or painting, so the harm to health is controversial.

Sheet size options

The length of a standard slate sheet is 1750 millimeters. The width varies depending on the number of waves on the surface. If there are six of them, this parameter is 1125 mm, 7 - 980 mm, 8 - 1130 mm. Many manufacturers of this type of product produce slate sheets of non-standard sizes. This circumstance must be taken into account when purchasing, so as not to make a mistake in calculating the amount of material required to perform a specific type of work. The slate dimensions determined by GOST are shown in the following table.

If necessary, ordinary gray slate can be painted, and how to do this, read the article. Currently, slate is also produced, painted at the factory. Laying, laying and fastening the material is possible using various methods. In this case, it is better to cover the roof with an assistant.

Requirements for the rafter system for slate roofing

Due to the fact that slate sheets have a fairly large weight, reaching up to thirty-five kilograms, the coating made from them places a serious load on the rafter system. Based on this, the following requirements are imposed on its arrangement:

• ability to withstand the total weight of the roof;
• unfavorable precipitation;
• weight of the installation team.

The lumber used to make the structure is pre-conditioned in stacks. During the drying process, the beams bend; they should be laid with the convex part down for unhindered drainage of moisture. Knotted wood cannot be used; it will not withstand the load placed on it.

The smallest cross-section of lumber for arranging the rafter system is taken to be 5 cm * 18 cm, the lathing for laying slate is made of 6 cm * 6 cm bars, and each sheet, when strengthened, must rest on at least two bars. The angle of inclination of the roof slope is of great operational importance: the smaller its value, the more often the beams should be located.

A continuous sheathing is installed at the minimum permissible angle of inclination, since in this case it experiences maximum load. The ends of the nails used for fastening should not protrude outward from the wood; under no circumstances should they be bent so as not to limit the mobility of the structure. Over time, the components of the roof will be subject to shrinkage and displacement. The fasteners must be of high quality; slate roofing is subject to significant operational loads.

Let's calculate the amount of slate for the roof

You can calculate the amount of slate to cover the roof by remembering your school geometry lessons. To do this, the measured length of the roof eaves is divided by the width of a standard slate sheet. The result is the number of sheets in the first row. This figure should be increased by ten percent, since the installation is done with overlap.

Next, the distance from the ridge to the roof overhang is divided by the height of a standard slate sheet. As a result, the number of rows required to cover one roof slope is determined. The resulting value also increases by approximately fifteen percent.

By multiplying the obtained values, we find the desired result, showing how many sheets of material will be required to complete the work on one slope. If the roof has a complex shape, it is divided into simple geometric shapes, their area is determined using formulas and calculations are made in the same way. Of course, if triangular-shaped elements are needed, there will be a lot of waste that cannot be used.

Preparation for installation

Before starting work, you should prepare the necessary tools and a flat surface on which you will drill holes and cut slate sheets. For the convenience of performing all manipulations, an unobstructed approach to the work site should be ensured. The following materials and tools will be required:

• ladder and ropes;
• hammer and nails;
• grinder and drill;
• metal hooks and a respirator.

The slate is lifted using metal hooks and ropes. Having hooked the sheet with ropes thrown over the block, it is pulled to the required height. This way one person can lift the slate. If a team of roofers is working, they can pass sheets to each other. standing on the stairs.

Plain gray slate can be painted before installation to close microscopic cavities and create a smoother surface that makes it easier for precipitation to roll off the surface. Asbestos is subject to thermal expansion, so holes of a larger diameter are drilled into the sheets than those used for fastening nails.

Instructions for laying slate on the roof with your own hands

The technology for performing the work is not noticeably complicated. Installation of slate is carried out as follows. First, the material is laid in one row, while cutting the internal corners. This manipulation improves the appearance of the coating and prevents snow from penetrating into the cracks under the influence of wind load. To cover the roof, you need to follow the instructions below:

• the truss structure is checked;
• a beam is strengthened in its lower part to organize even laying of slate sheets;
• The initial row is fixed along the timber using nails;
• subsequent rows of material are laid up to the ridge.

Installation of slate sheets is carried out from the bottom. The slate elements are fastened with special roofing nails or self-tapping screws. Fasteners must be made of high quality steel. Nailing slate with your own hands is not difficult at all.

How to lay asbestos slate correctly

The service life of the roof as a whole ultimately depends on how correctly the asbestos slate is laid. When performing work, you should carefully observe the technological details of the installation process. The first step is to install a good sheathing, which is the base for laying asbestos sheets. A layer of waterproofing made from a waterproof film is initially laid under the slate.

Installation is carried out staggered or with sheets offset relative to each other. The first method, in which each subsequent sheet is laid on top of the previous one, does not require the use of half sheets, but it does require cutting off the corners, which complicates the work. When installing with the sheets of the top row shifted halfway, there is no need to trim the corners, but you will have to cut some of the slate sheets lengthwise.

Asbestos slate is fixed with nails with an increased head size. A sealing washer is placed under it to prevent the penetration of atmospheric moisture.

The service life of the roof depends on the reliability of the fastening.

Fastening sheets with nails or screws

Fastening sheets with nails is considered the most reliable. They prevent displacement and deformation of the material. Nails should be driven in at the highest point of the wave, placing them strictly vertically. The hardware should be held not with your hand, but with pliers, so as not to break the slate with an inaccurate blow. It is better to use rough nails with notches that allow them to be securely held in the body of the wood, however, if dismantling is necessary, they are quite difficult to remove.

The sheets can also be fixed using self-tapping screws. This method has its advantages, since, due to the hardening of the metal, during manufacture such fastening material is characterized by very high strength. In addition, the variety of head shapes and lengths makes it easy to select self-tapping screws to perform a specific job. They are equipped with high-quality sealing gaskets that prevent moisture penetration. To reduce operating time, screw in self-tapping screws using a power tool.

Installation of connections to the chimney

There are many options for connecting the roof to ventilation pipes and chimneys. In general, the work is performed as follows. At the junction of the roofing covering and the chimney, a galvanized collar with a hole for the chimney outlet is installed on top of the waterproofing layer.

The pipe is lined with asbestos sheets, and slate is laid on top of the collar. The gap between it and the chimney is filled with cement mortar.

Installation of additional elements

To give the roof a complete appearance and prevent negative environmental impacts, additional elements are installed at the final stage of the work. In addition to functional, they also have a decorative purpose.

In the best case, the ridge is decorated with industrially produced parts made from a mixture of asbestos and cement. They can be replaced with your own curved sheet of galvanized steel. Collars are installed on dormer windows, ventilation and chimneys, secured with self-tapping screws. Galvanized trays are installed on the valleys.

With a large selection of roofing materials on the construction market, asbestos slate continues to be in high demand. This popularity is due to its high resistance to temperature changes, the ability to withstand fairly high loads and reasonable price. At the same time, a properly installed slate roof can last more than fifty years. In order to properly cover a roof with slate with your own hands, you need to know several important conditions and rules, which you will learn about in this article.

Choosing slate for roofing

Asbestos slate

bitumen euro slate (): its cost is 1.5 times higher than asbestos, but the rigidity of this material leaves much to be desired; it can only be laid on a perfectly flat and hard surface, otherwise it will immediately warp; plus bitumen, even reinforced, melts easily in the sun;

Ondulin

metal: made from galvanized steel, as a rule, can be coated with a protective polymer layer; significant disadvantages are the tendency to corrosion and low noise absorption;

Metal slate

translucent plastic PVC, acrylic or polycarbonate: used mainly for covering greenhouses.

Plastic slate

The best option for roofing is 6-, 7- and 8-wave asbestos material. The thickness of the 7- and 8-wave is 5.8 mm (the 7-wave can also be produced in 5.2 mm). 6-wave sheets are thicker– up to 7.5 mm, they are used mainly for industrial buildings. Flat slate Most often used for fencing and facade finishing.

For small roofs or roofs with complex configurations, the ideal option is 7-wave slate, producing less waste. On large area roofs, 8-wave material is used. Its use can significantly reduce installation time. Reducing the number of overlaps significantly reduces the weight of the roof.

Sheathing device

Bars that are too thick will accumulate moisture, and bars that are too thin may simply not withstand the weight of heavy slate. To install the sheathing, use well-dried timber without knots and cracks with a diameter of 50-75 mm.

1. To protect against rotting, before laying, the bars should be treated with any antiseptic.

2. The sheathing is installed from the bottom up. In this case, the boards must be joined on the rafter legs staggered, perfectly straight, without sagging, bumps or protruding nails.

Important! The roof ridge must be positioned strictly horizontally, and all slopes must be level, without kinks. If necessary, they should be aligned.

Slate lathing

3. The first cornice beam must have greater height. To do this, you can use linings equal to the thickness of the slate (5-8 mm). This is necessary for a tight fit of the roof to the frame when the sheets overlap. It is necessary to increase by half the thickness of the slate (by 3 mm) even bars.

4. The bars are nailed to the rafters or screwed with self-tapping screws along the edges, and the caps must be tightly recessed into the wood.

5. Continuous sheathing used mainly with a slight slope (6-12°) of the roof and a fairly large roof area. In other cases, the lathing is done sparse and is positioned so that each sheet of slate lies on 3 bars with a margin of 15 cm on each side. The width of the step between the transverse bars depends on the length of the sheet.

Marking and fastening the sheathing

Important! To ensure ventilation when installing a continuous sheathing, a gap of 1 cm should be left between the bars.

6. Lathing is done on the eaves overhangs and valleys (the junction of two slopes) solid. Additional bars are also installed along the entire ridge.

7. At the chimney Additional bars are attached at a distance of 13 cm. The resulting space is subsequently covered with galvanized steel.

Important! The sheet of metal near the chimney should be located under the slate and waterproofing layer. In the absence of waterproofing, the upper edge of this sheet is laid under the slate, and the lower edge is placed above it.

Installation of sheathing near the chimney

Laying slate

1. The slate is lifted onto the roof using ropes with hook along guide bars installed obliquely. At the same time, two people are on the roof and accept the sheets, and the third one catches the sheets and secures them from falling.

2. To avoid mistakes, the slate is pre-sorted and laid out on the sheathing. If necessary, it is trimmed steel cutters or grinder with an abrasive disc.

3. To protect against moisture, it is advisable to lay a layer under the slate layer waterproofing. For these purposes, roofing felt is most often used.

Important! With a slight roof slope (up to 12°), roof waterproofing is required.

4. Installation is done down up taking into account directions of prevailing winds so that in places where there is an overlap the slate is blown through as little as possible. For marking along rows the cord is stretched. Start laying on the right.

When laying, take into account the direction of the prevailing winds

Important! If you carefully examine the slate sheet, you will notice that wave height it's different. On one side of the sheet (overlapping) it is higher than on the other. This is done so that the slate does not bulge when overlapped. When installing, be sure to take this difference into account.

5. When calculating the amount of slate, you should take into account the size overlapping sheets, which is 1 or 2 waves. Overlapping sheets in adjacent rows– 12-20 cm. In order not to cut the slate, the size of the overlap can be increased if desired.

6. When covering in one wave, a coefficient of 0.8 is used (that is, the useful area of ​​the slate is multiplied by this value). With an overlap of two waves, this coefficient will be equal to 0.7. Thus, to find out the required number of sheets, the roof area should be divided by the sheet area multiplied by 0.8 (with an overlap of two waves 0.7).

7. Roof ridge installed last. To do this, a ridge blank is prepared from galvanized steel, which will be laid on top of the slate. Wherein its bend angle should be slightly less than the slope of the slope. The same nails are used to fasten the metal.

Ridge installation

Advice. Since the main enemy of the foundation is melt and rain water flowing from the roof, you should take care of the drainage when planning the roof.

Types of slate laying

with cut corners: this method is used for a narrow roof slope; the corners of two diagonal sheets are cut off; the sheets are arranged in a checkerboard pattern, the second row starts with half a sheet; since joining four sheets at one point is unacceptable, with this method the lower edge of the sheets located diagonally is cut off by 10-12 cm.

The first method is simpler, does not require frequent pruning, and therefore is used most often. However, when laying with an offset, material consumption increases significantly. In addition, the edge of the roof with this method is uneven.

Slate laying methods

Laying without displacement (with cut corners)

Advice. In case of strong winds or an abundance of snow, as well as on low-slope roofs, it is advisable to use double overlap.

Joining sheets at one point is unacceptable

How to nail a slate sheet

2. The sheets are attached to the sheathing using ordinary galvanized or special 7-12 cm slate nails, which come complete with rubber gaskets or galvanized washers.

3. They score with their regular hammer. In this case, the nail together with the gasket is inserted into a previously prepared hole and driven in, but not all the way, but so that the slate cannot be moved from its place.

4. Do not bend nails under the sheathing. If they are too long, it is better to cut them off.

Important! Only fasten slate in the upper crest of the wave. The likelihood of water getting into the mounting hole with this method is minimal. With this method, during thermal expansion of the slate, the risk of loosening the fastening will be minimal.

Slate Nailing

5. Sheets with 6 waves are attached with two nails in the 2nd and 4th waves to the bottom bar of the sheathing; two more nails will go through this sheet after the next sheet is applied.

6. To prevent the slate from cracking, extreme wave never nailed down; You should not make fastenings too close to the edge: you should step back 15 centimeters from it.

7. 7-wave slate is nailed into the 2nd wave, and then into the 5th, 8-wave sheets - into the 2nd and 6th.

8. To the extreme sheets slate, three fastenings are first driven in: one in the 4th or 5th wave in the lower part of the sheathing, the other two in the 2nd wave to the lower and middle beam of the sheathing; accordingly, there will be only five nails in such a sheet (two more will appear after nailing the top sheet).

9. On the cornice the sheets are attached to three nails: the first should go into the 4th or 5th wave and two into the 2nd wave.

The slate is secured with special nails using backing plates

Watch a video on how to cover a roof with slate with your own hands:

Roofs for the installation of which asbestos slate is used have been highly popular in the construction industry for many decades, and despite the fact that in recent years many modern roofing materials that meet all requirements have appeared on the market, asbestos cement sheets still do not lose their relevance. Due to the relatively low cost of the material, its chemical inertness and resistance to static loads, neither roofing iron nor metal tiles have the right to compete with it. The aesthetic properties and technical parameters of slate, as well as the ease of installation and long service life are in no way inferior to those of its more expensive analogues, which also has a significant impact on the popularity of the roofing material. The steady popularity of slate, like any material used in the construction industry, has experienced ups and downs, but the use of slate in country and individual construction has revived when multi-colored asbestos cement sheets went on sale. But their appearance did not in any way affect the popularity of classic slate, which, having stood the test of time, has not lost its consumer. The first question that arises before the master when the conversation turns to slate is how to lay this roofing material. Like any construction process, laying slate includes several stages, each of which is characterized by certain nuances. Their compliance plays an important role in the effectiveness of the final result, and, accordingly, the length of the roof’s service life. In this regard, in this article we will answer the question: “How to cover a roof with slate?”

Slate: basic information about the material

Slate is a traditional roofing material made from asbestos cement and is characterized by high mechanical strength and durability. Today, both flat and wavy slates are available for sale, as well as models produced in multi-colored designs. Asbestos-cement sheets cannot be classified as environmentally friendly materials, since it has been proven that asbestos can be harmful to human health during operation. Taking into account this circumstance, slate can only be used for external work.

Important! Wave slate can only be used for installation of roofs with a slope, the angle of which must be at least 22 degrees. If the roof slope is small, it is necessary to additionally seal the joints, increase the overlap of the slate and use additional fasteners. To maintain the integrity of the slate sheet, holes for fasteners must not be punched, but drilled.

Important! Material based on asbestos cement is supplied in packages where slate sheets are lined with polyethylene. They must be stored in this form until they are used for work.

Before laying slate, experienced craftsmen recommend covering it with acrylic paint, which helps extend the service life of the material. The service life of unpainted material is about 20 years, while slate coated with acrylic paint lasts several times longer.

Before we answer the question: “How to lay slate?”, it should be noted that the installation of slate, like any other construction project, requires preliminary planning. Taking this into account, first of all it is necessary to consider all possible options for the shape of the future roofing, since this is the determining factor when calculating slate.

Important! Roofs for the installation of which sheet materials are used can be flat, that is, single-pitched with a slope of no more than 1-2 degrees, without attics (single and gable with a slope of no more than 7%), as well as attics, the design of which implies a slope of more than 40 degrees. . It is important to know that experts do not recommend giving preference to intermediate options (for example, roofs with a slope of 25-35 degrees), since it is in this case that the maximum amount of snow accumulates on the roof. Modern development of construction technologies makes it possible to equip complex roofing structures of any configuration, including those with four slopes, however, for arranging slate roofs, it is recommended to choose a simpler geometry.

Advantages and disadvantages of slate: what do you need to know about slate roofing?

Features of modern equipment and the development of innovative technologies have significantly improved not only the appearance of slate, but also its performance characteristics. Among the main advantages of slate are the following:

• Frost resistance and resistance to sudden temperature changes;
• Resistance to high humidity;
• Good tolerance to ultraviolet radiation;
• The ease of installation and the possibility of doing it yourself is another reason to pay attention to this roofing material.

Despite a wide range of advantages, slate also has certain disadvantages that significantly complicate installation activities and are the reason for refusing to use this roofing material.

Disadvantages of slate:

• Relatively large weight of slate sheets;
• The fragility of slate requires care during transportation of the material and installation activities;
• The slate is made on the basis of asbestos cement, which contains asbestos, which has a negative effect on human health;
• Taking into account the previous factor, you need to know that during the installation of a slate roof, provided that slate cutting is required, it is necessary to use personal protective equipment.

How to choose slate: basic rules

In most cases, domestically produced slate is used on construction sites, the dimensions of which are regulated by GOST 30340-95:

• for six-wave slate: sheet thickness is 5, 6 and 7 mm; width - 1125 mm;
• for seven- and eight-wave slate: sheet thickness - 5 and 8 mm; width - 980 and 1130 mm, respectively.

The length of the sheet, regardless of the type of slate, is 1750 mm.

Knowing the brand of slate, you can determine not only the number of waves, but also the wave height, which is the distance between the crest and the bottom, as well as the wave pitch, which is equal to the distance between any points of adjacent waves. Let's look at this using slate grade 40/150-8 as an example. 8 in this case means that this slate has eight waves, 40 mm is the wave height, 150 mm is the step length. These parameters must be taken into account when calculating slate, since when laying staggered, which involves superimposing waves of vertical sheets, the consumption of six-wave slate exceeds the consumption of eight-wave slate. This is due to the width of the wave step, which is slightly larger for six-wave slate than for eight-wave slate, and therefore the area of ​​material required for overlap increases.

The sediment collection system is another factor that influences the order in which slate roofing is laid. If you plan to install a gutter under the overhang of the last slate row, it is enough to carry out the installation in such a way that the slate sheets of the last row protrude beyond the facade line by no more than 200-250 mm. If you prefer a direct type water discharge system, which involves discharging water from the roof directly onto the adjacent area, the size of the protrusion should be at least 400-500 mm.

Slate roofing installation technology: main stages

Installation of slate roofing is carried out in several stages.

• Preparatory activities, including calculation of the required amount of material, as well as its acquisition and delivery to the construction site;
• Installation of the rafter system and the process of arranging sheathing under slate, combined with laying waterproofing materials;
• The final stage is the installation of roofing material. He is the most responsible, since the quality and duration of the service life of the roof depends on him.

How to calculate the required number of slate sheets? Basic recommendations

Before laying the slate, you need to calculate the amount of material that will be required to install the slate roof. To find out this, you need to carry out simple calculations, the procedure for which will be discussed below:

• Firstly, the length of the roof slopes is multiplied by their height;
• The result obtained, corresponding to the roof area, must be divided by the area of ​​the slate sheet;
• As a result of these calculations, we received the required number of slate sheets, which must be increased by 10%, which is due to the slate roof installation technology, which involves overlapping it.

Preparatory stage: arrangement of load-bearing structures

The preparatory stage includes the installation of sheathing, for the arrangement of which it is necessary to prepare material from durable wood, but it is not necessary to choose oak or larch. This is due to the fact that slate is a fairly light material, and therefore any dense wood can be used to install the sheathing. Before installing slate with your own hands at the stage of arranging the sheathing, the wood must be treated to prevent rot.

It is important to note that before installation begins, the slate must be stored indoors in its original packaging and in a horizontal position, covered with plastic film.

Having decided on the design and slope angle, before installing the slate on the roof, it is necessary to lay the rafters, for the manufacture of which 50x180 timber is used. The rafters are installed in such a way that the narrow side is vertical.

Important! If you use boards to make the sheathing, the distance between them should be from 200 to 1250 mm. If beams are used, they should be laid in such a way that each sheet of slate rests on at least three beams, that is, the distance between them should be approximately 400-450 mm.

If you plan to install a gutter, it must be installed before installing the slate sheets. Along the sheets of the last row of roofing, it is necessary to nail a strip of metal to the bottom edge, the width of which is 300 mm and a thickness of 2-3 mm, which is necessary to prevent the sheets from chipping. A layer of waterproofing material must be applied to the metal strip on the inside and outside. In the places where the slate is attached, the required number of fasteners are drilled into the metal.

Important! To improve the performance characteristics of the attic roof, experts recommend laying a vapor barrier membrane under the slate.

It is important to know that horizontally adjacent slate sheets must always be laid with an overlap, which can be one or two waves, while the latter option is more expensive, but it guarantees higher strength characteristics of the roof. Due to the fact that problems often arise when fixing more than two sheets of slate at one point, there are several ways to solve them, and, consequently, methods of laying roofing material.

The most popular method of installing slate roofing is “staggered laying,” which involves laying each new row offset relative to the previous one. Thanks to the use of this technique, there is no coincidence of wave overlaps in each of the rows, as a result of which only two sheets can be joined at each individual point. To carry out the shift in this case, it is necessary to trim several waves from the outermost sheet. The disadvantage of this method is that during the installation of the last vertical rows of slate, an uneven roofing edge is formed, which requires additional leveling.

As for eight-wave slate, there is a more practical modification of this installation method. In accordance with it, it is necessary to cut in half all the first sheets of odd horizontal rows (i.e. into 4 waves), which will lead to a fairly clear (through the row) repetition of the displacement lines and a more aesthetic appearance of the roof. In addition, using two sawn halves of a slate sheet, you can begin installing two rows at once. Once you have installed the first sheets, including the halves, you can simply lay the sheets horizontally without worrying about offset, as offset formation occurs naturally. However, trimming may be required during the end-edge alignment process.

If you are concerned about material waste, a non-offset installation may be your best option, although more labor intensive. In accordance with this technology, in the case of laying sheets from left to right, it is necessary to trim the corners of the sheets forming the top row of the roof by no less than 100 mm in wave width, and no less than 120-140 mm in wave length. In this case, the lower corner is cut from the side covering the previous sheet of the horizontally oriented row. Experts say that thanks to the use of this technique, the most optimal overlap of all sheets of material is achieved not only horizontally, but also vertically.

In the process of laying slate, it is necessary to use nails, self-tapping screws or special screws, characterized by the presence of an enlarged head and a rubber gasket under it.

Important! To prevent damage to the roofing material during installation, it is necessary to mark the slate in advance and drill holes in it for fasteners. It must be remembered that the diameter of the hole should be 2-3 mm larger than the diameter of the screw or nail.

The holes for fastening elements should be located as follows: the first hole is in the lower corner of the slate sheet, the second is in the second overlapped wave, the third is symmetrical relative to the previous one, that is, in the second overlapped wave. The final sheet of the row, located horizontally, must be additionally secured in the area of ​​the sixth (penultimate) wave.

Important! It must be remembered that regardless of the type of fastening elements, they must be installed at the crest of the wave, since a different placement of screws or nails will cause premature (and quite rapid) destruction of the roofing. At the same time, taking into account the magnitude of the vertical overlap between the rows, 120-150 mm retreat from the transverse edge of the row.

How to maintain the integrity of slate: basic safety rules

In the process of laying slate, it is important to observe not only the installation technology, but also safety precautions. In order to be able to clean it during the operation of the roof, as well as to carry out similar work on top of the slate, it is necessary to install wooden scaffolds, supplementing them with transverse strips-steps. If the roof is installed on a building higher than 6 m, a fence made of metal reinforcement must be provided around it. In order to carefully lift a sheet of slate to a construction site, experts recommend using a system of blocks and a nylon cable. If the roofing installation is carried out on a low building, assistants can supply the material.

Important! Moving along the installed coating must be carried out carefully. To move freely along the slate roof during its repair or maintenance, lay wooden ladders on it, thanks to which the load will be distributed evenly.

During the work it is necessary to use safety ropes and other devices. As for safety precautions when working with asbestos-cement materials (cutting and drilling slate), they imply the use of personal respiratory protection (respirators) that will protect the respiratory system from harmful dust.

To equip ridges, cornices, roof joints, junctions with pipes and similar areas, experienced craftsmen recommend using commercially available special asbestos-cement elements, after installing and securing them with cement and bitumen mastic, you don’t have to worry about the strength of the roof being installed. Sometimes wooden boards or galvanized strips are used for these purposes, however, due to the low aesthetics and ineffectiveness of this method, it is not widely used.

If all technological stages of laying this roofing material are followed, the service life of a slate roof without repair (with the exception of emergency situations caused by spring influences) reaches 50 years or more.

Rules for caring for slate roofing: main points

Slate coating requires simple maintenance, which will significantly extend its service life.

Its main provisions are as follows:

• Inspection activities and roof cleaning must be carried out twice a year - before and after the rainy season;
• Despite the fact that even a broom can be used to clean the roof, these activities can be significantly accelerated by using an electric pump;
• In winter, it is recommended not to neglect the need to clear ice and snow;
• If you do not have the opportunity to independently care for your roof, use the services of specialized teams.