Laying slate on the roof: We study the technology of creating slate roofs

Slate is a material of choice for roofing because of its natural beauty, longevity, and strength. Slate installation is a craft that blends antiquated methods with cutting-edge roofing technology. Every slate tile is made from real stone that has been meticulously extracted from the quarry and cut into thin, level pieces that are perfect for roofing. Slate roof construction requires painstaking attention to detail, guaranteeing long-term structural integrity as well as aesthetic elegance.

Making the underlayment ready is one of the most important steps in installing slate on a roof. An underlayment that is resilient to weather is laid down prior to the installation of the slate tiles. This underlayment helps to give the slate tiles a smooth surface and acts as a barrier against moisture. Throughout its lifespan, a slate roof that has been properly underlayment will remain weather- and water-resistant.

Slate tile installation calls for dexterity and expertise. Stainless steel or copper nails are used to attach each slate tile to the roof deck one at a time. The tiles are laid out in a particular pattern, usually working their way up from the bottom edge of the roof. Top-lapping is a technique that helps divert water off the roof and stops leaks.

With regular maintenance, slate roofs can endure for up to a century, making them renowned for their longevity. Slate is a naturally occurring material that is resistant to rot, fire, and insect damage, making it a sustainable option. Slate roofing adds a sense of elegance and prestige to buildings’ architectural aesthetics in addition to its practical advantages.

We explore the science and art involved in creating slate roofs. "Laying slate on the roof." This article covers every aspect of building long-lasting and exquisite slate roofs, from selecting the best materials to comprehending the painstaking installation procedure. In order to ensure that your roof weathers gracefully and dependably over time, whether you’re a homeowner contemplating slate for its durability and aesthetic appeal or a roofer hoping to become an expert in this age-old craft, our guide offers crucial insights into the technology supporting slate roofing."

Speaker laying methods

Slate is fixed on the crate in horizontal rows, working from the bottom up (from the cornice) to obtain a roofing. A wave or two applies each new sheet in the row to the one before it. Moreover, each succeeding row is typically moved by 120–200 mm relative to the preceding one.

The slate can be arranged in two different ways:

  • Razzing -when the sheets of slate of one horizontal row are mounted with a shift of 1-4 waves in relation to the sheets of the neighboring row. The joint line is stepped. This technology is recommended for slopes of roofs, wide in the transverse direction (horizontally), but narrow in the slope.
  • Without displacement – when the sheets of slate are mounted with the same, even rows, without a shift. The joints of all rows form one line. Since when laying it is not allowed to arrange a double overlap (that is, combine more than 2 layers of slate at one point), the edges of the sheets are cut at an angle of 30 ° -60 °. This method is most rational for covering slopes, wide in slope, but small on the diameter.

Typically, a scope is used to lay a wave slate. Given that it requires fewer trimmings, this option is less time-consuming. Slate mounting without displacement is far more challenging because nearly every sheet needs to have its corners trimmed. However, one big benefit of such technology is that it makes material saving possible.

Think about how to roof with slate step-by-step, paying attention to how the two layout schemes differ.

Shifer styling technology

Stage #1. The device of the crate

The base, a crate that is fixed directly on the rafters, must first be prepared in order to fasten the slate. The crate is sparse and continuous.

Continuous crate: this is a plywood or board flooring made from OSP. Typically, a base of this kind is employed when covering the roof with slate that has a non-standardly thin thickness.

A rarefied crate—a set of bars installed with a specific step over the rafters—is advised for a typical slate with a thickness of GOST. A suitable crate cross section ranges from 40 to 70 mm. They avoid using too thin bars because they could be damaged by an external load (like snow falling on them). Not to mention unwieldy bars. They can split the fibers of the asbestos cement with a bitch, causing the slate to crack.

As part of the crate frame, it is recommended to use bars of different heights. Private bars usually have a section of 60×60 mm, they are fixed in odd rows. Even rows make up elements whose height is slightly higher – half the thickness of the slate used. For example, if the thickness of the slate is 6 mm, then the height of the "even" bars is 63 mm. A different height – 66 mm – has the first (cornice) bar, which should rise above the ordinary to the thickness of the slate leaf. For the same type, another scheme is often used: they use rails of one height – 60×60 mm but, in even rows and near the cornice, they are increased using linings 3 mm thick.

Using screws or nails, the crate is fastened to the rafters at a straight angle. As the slate is made of sturdy, non-bending materials, installing each sheet only requires three support bars. The length of the sheet determines how far the crate steps from the bars. The crate step is 700–750 mm, and the standard length is 1750 mm.

For the purpose of later attaching skating components to them, 1-2 of the crate’s bars are mounted on the skate (one on each slope). In actuality, the bars’ height is chosen at that very moment.

Do a crate around the chimney in addition. To do this, standard bars are fastened around the pipe’s trunk, keeping a minimum of 130 mm between them (to ensure fire safety).

Stage #2. Calculation of the number of slate

Accurately calculating the quantity of slate is another crucial step that will shield the roofer from having to rush to buy one or two missing sheets and arrange for transportation.

You must realize that the material does not reach the roof’s direct coating on its whole surface. Under the overlap, a portion of the area (around the sheet’s perimeter) is lost.

Consequently, the following method is used to calculate the number of slates:

1. Use the following formula to find the number of slate in the transverse (horizontal) series (P):

2. Use the following formula to find the number of slates in the longitudinal row (n):

3. After rounding the results to the nearest whole number, the total number of sheets for each slope of roof is obtained. The computed number of sheets (+10% for marriage and battle) is obtained twice if the roof is gable.

Stage #3. Schifer sheets cutting

Sorting and cutting the slate sheets according to the chosen laying scheme is required before lifting them onto the roof.

Several tools are available for cutting slate:

  • grinder;
  • hacksaw on wood or foam concrete;
  • electrician;
  • Using a drill.

Slate can be cut more quickly and easily with a grinder that uses a diamond disk or a stone (concrete) disk.

  • A slate of slate is laid on bridges from the boards so that the cut place is raised above the ground;
  • make the cutting line of the cut with a flat wooden rail;
  • The cutting place is watered with water to avoid overheating of the disk, make the slate softer and supple, as well as besiege the released asbestos -cement dust;
  • They perform the cut, constantly wetting the cutting line and the disk of the grinder (pouring them with water from the bottle).

Similarly, an electrician or hacksaw are used to saw the sheets; however, you must use extreme caution when using these tools to avoid breaking them.

Techniques for cutting with a slate nail or drill require particular consideration.

A 2 mm drill bit is used to drill through the openings made along the cutting line at 0.5 cm intervals. Following the drilling, the slate is split along the intended line after the sheet is placed on the support (a table, for example) and pressed to the other edge.

To create through holes, a hammer and a sharpened nail can be used in place of a drill. This can be accomplished by placing a nail on the desired line and hammering the hat. Blows ought to be clean, sufficiently forceful, but not pointy. Consequently, puncture several point holes that are close to one another. The sheet is then divided into two halves.

A video tutorial demonstrates how to cut slate sheets with a grinder using this technology:

Stage #4. Laying of slate sheets

Slate is first laid on the side that faces the direction of the predominant winds. That is, if there are strong winds blowing from the right, start installing the sheets from the left, and vice versa. This will prevent snow and rain from blowing into the areas where the sheets overlap.

To level the slate’s slopes, a cord is pulled along the cornice at a distance equal to the length of the overhang. You can use a flat wooden rail in place of a cord.

The workflow in the event of a scope is as follows:

1. Whole slate sheets are used to create the first horizontal row. One or two waves of the preceding sheet are overlapped by each succeeding sheet (usually, one wave falls on the overlap). Roofing nails or screws with soft (rubber) gaskets are used for the mount.

2. Depending on the required displacement of, the first sheet is divided into several waves in the second row. Place whole, unstressed products after that. The sheets form a 200 mm overlap with a slope of 15-20 ° and a 150 mm overlap with a slope of more than 20 ° with respect to the underlying row. In other words, less overlap is allowed the steeper the slope.

3. Sheets removed from the first sheet of the underlying row and cut into twice as many waves form the basis of the third row and all subsequent rows. For instance, if the first row’s first sheet was shortened by one wave, the first row’s first sheet will need to be shortened by two waves, then by three waves, and so on. Doing a displacement of half the slate’s width is more practical. In this instance, only half of the sheets in each even row will need to be cut. Entire sheets are used to compile odd rows.

4. The final skate is the one that emerges from the cross-cut sheets.

In the event of relocation:

1. Without trimming, the first sheet is laid out completely. Adjust it with self-tapping screws or nails, then line it up with the cord. If the installation starts on the right side of the slope, the upper right corner of the next sheet of the first row is mowed at an angle.

2. The lower left corner of the first sheet in the second row is cut, and it is then joined with the cut angle of the second sheet in the front row. The next set of sheets is mowed diagonally in the upper right and lower left corners. Only the upper right corner is missing from the final sheet of the second row (which is on the left).

3. The upper row’s components (under the skate) are actually cut in height as well as along the lower left corner. There are no shortcuts taken in the final sheet. When laying sheets from right to left, a comparable plan for forming angles is dependable. If one is installing from the left to the right, pruning is done in the corners opposite to the direction of the installation (left angles to right, and vice versa).

Stage #5. Installation of additional elements

The installation of finishing touches starts once the roof has been covered with slate. It is recommended to use special skating parts made of asbestos cement to cover the skate. These elements are all made up of two parts that are hinged together. You can use your own or a galvanized sheet bent on a leaf beasting machine in place of the factory part.

Corner pieces made of asbestos cement or collars made of galvanizing are used to decorate the collars of chimneys, auditory windows, and wall placements. With the aid of self-tapping screws driven through the wave crests, they are secured atop slate sheets. The apron’s upper edge is sealed and fastened to the wall. At least one regular sheet wave overlaps the bottom edge.

Endovs are covered with asbestos-cement or galvanized trays, which are installed from the bottom up. Here, the slate sheets and the tray’s longitudinal walls should overlap by at least 150 mm.

The final styling of the slate roof was achieved upon the consolidation of the additional elements.

Features of slate fastening on the roof

The choice of fasteners and how they are used to secure the slate to the roof is a crucial detail that needs to be covered separately.

As anchors, you can employ:

  • Slate (roofing) nails. Produced from strong steel, their main feature is an enlarged hat reaching 14 mm in diameter. To exclude the appearance of rust, hats are made of galvanizing or metals covered with anti -corrosion composition. The length of the slate nails should be directly proportional to the height of the wave of the slate. That is, the higher the waves of the slate, the longer the nails driven into them. According to the recommendations of experts, the length of the nails should be 10 mm larger than the total height of the slate wave (where the fasteners will be driven) and the thickness of the crate (bar or boards). The excess of the rod is not necessary.
  • Self -tapping screws for slate. These fasteners are more expensive than nails, but also more convenient to work. Self -tread heads can have three execution options: for a wrench (hexagonal shape), under a flat screwdriver (with a straight slot), under a cross -shaped screwdriver (with a cruciate slit). Under the hat is a sealing goal with a rubber gasket. Some manufacturers stain the heads and washers in different colors (most often – according to the RAL palette).

There are two options for mounting fasteners:

  1. In the holes pre -drill in the slate. Their diameter should be 2-3 mm wider than the rods of fasteners. The resulting gap will protect the slate from cracking with the movements of a wooden crate, but can cause water flow under the roof. To prevent this from happening, a rubber gasket is put on the fasteners, which sealing the slate roof. Self -tapping screws are equipped with such a gasket constructively, unlike roofing nails. Therefore, under nails, a waterproofing washer will have to be bought separately or cut it independently – from rubber, roofing material or felts. Then it is put on the rod, under the hat.
  2. Without pre -drilled holes (This method recommends most "experienced" masters). In this case, only roofing nails without gaskets are used to fasten the slate on the roof. The nail is driven into the coating with light beats of the hammer so that the asbestos -cement layer crumbles from blows, and not crack. Otherwise, slate can burst. However, even with properly carried out technology for driving nails directly into the slate, it often cracked. This is due to the poor quality of the material, which, unfortunately, occurs entirely.

An essential component of the fastening is leaving a small gap of 2-3 mm between nails or self-tapping screws during installation to account for temperature variations. If you disregard this advice, the slate roof will begin to crack soon.

Only where the slate meets a crate (to join a roof sheet with the crate’s material)—the upward-protruding portions of the waves are where fasteners are placed. The mount is done between 80 and 100 mm away from the sheet edges.

Suggested placement for the screws (nails):

  • for a 5-wave slate-mount in the 2nd and 4th waves;
  • for the 6-wave slate-mount in the 2nd and 5th waves;
  • For 8 wave slate-mount in the 2nd and 6th waves.

Six nails (screws) are needed for each sheet because the slate typically rests on three bars of the crate and the fastening is done at the locations where two waves meet the crate.

Introduction to Slate Roofs Learn about the traditional technique of using slate as a roofing material.
Benefits of Slate Discover the advantages of slate roofs, such as durability and aesthetics.
Installation Process Step-by-step guide on how slate roofs are installed, from preparation to finishing.
Maintenance Tips Essential tips for maintaining a slate roof to ensure longevity and performance.

Slate roof installation demands exact planning and execution to guarantee longevity and visual appeal. Slate is a common material for roofing because it is a long-lasting and weather-resistant natural stone. Because of its special qualities, it can be used in a variety of climates and architectural styles.

The first step in making a slate roof is choosing premium slate tiles. These tiles come in various sizes and thicknesses and are usually obtained from quarries. Hand-selected for quality and consistency, each slate tile guarantees a uniform look throughout the roof.

Starting at the bottom of the roof and working your way up, the slate tiles must be installed in overlapping rows. Nails or hooks are used to firmly fasten each tile, preventing water seepage and withstanding wind and other environmental factors.

Periodic inspections and repairs are necessary to maintain a slate roof, though slate itself requires little upkeep because of its durability. Slate roofs are a sustainable and economical option in the long run because they can last for more than a century when installed properly.

In summary, installing slate on a roof requires a careful procedure that combines artistry with long-lasting materials. Slate roofs provide timeless beauty and dependable protection, guaranteeing a home stays both structurally sound and aesthetically pleasing for generations to come, whether for a modern construction project or a historic restoration.

Video on the topic

Schifer laying so that the roof with a small slope does not flow

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Alexandra Fedorova

Journalist, author of articles on construction and repair. I will help you understand the complex issues related to the choice and installation of the roof.

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