Soft roofing is increasingly used to design roofs in low-rise construction. It is practical, beautiful, modern and reliable. But the longevity of its service will depend on whether the installation was carried out correctly. Proper lathing for a soft roof is of considerable importance. How to make it correctly, what requirements should it meet?

Also known as asphalt shingles. It was first introduced to the building materials market about 30 years ago. This elastic material is made from fiberglass or polyester, which are impregnated with bitumen compounds. The result is a water-resistant, durable yet flexible material that is ideal for finishing roofs.

The surface of flexible tiles is always covered with a special coating - fine crumbs obtained during the processing of various minerals. And the bottom layer has an adhesive base that allows you to glue the tiles to the roof. This type of tile is used when arranging roofs with slope angles of at least 11-12 degrees.

On a note! Flexible tiles are distinguished by a wide selection of shades, colors, and sizes. That is why you should not purchase materials made by different manufacturers, even if they are very similar to each other.

Due to their softness, such tiles require a special base. It can only be laid on a crate made in a certain way.

What is lathing, its types

Lathing is an element necessary for every roof, which is a system of boards and beams on which it is attached. roofing material. It happens different types, the choice among which is made depending on what roofing material is used. For example, if the roof is covered with slate, then the sheathing may be sparse, that is, there will be gaps between its elements (a certain pitch). If soft coverings are to be installed on the roof, then the sheathing should be continuous, without gaps. To lay bitumen shingles, you will have to use a continuous type of sheathing.

On a note! The lathing can have two layers at once - sparse and continuous. Due to this, it will be possible to achieve good ventilation of the roof, install thermal insulation and improve the quality and reliability of the roof as a whole.

The sparse lathing is always laid perpendicular to the roof rafters (parallel to the ridge), the solid one is fixed on top of the mounted sparse one. At the same time, do not forget about laying heat and waterproofing materials.

High-quality and correctly installed sheathing for a soft roof must meet the following criteria:

• be durable;
• do not bend under the weight of the roofing material;
• remain resilient even under the influence of environmental factors;
• be level - do not have any bumps, protrusions, or irregularities, all sharp elements are removed from it, the heads of nails and screws should not protrude above the level of the horizontal surface of the boards;
• should not have large gaps between individual elements (maximum step - 1 cm).

On a note! Sometimes solid lathing is laid directly on the rafters, without using sparse lathing - the so-called single-layer flooring. This is done to speed up the construction process; usually the option is used only for houses that do not need enhanced insulation and waterproofing.

Materials for making lathing

Sheathing for soft tiles can be made from several types of materials. The main requirements for them are strength, reliability, durability and evenness.

Plywood most often used to create sheathing for soft tiles. This is an environmentally friendly material, multi-layered, quite wear-resistant, inexpensive, easy to use and durable. The main thing is to purchase a moisture-resistant option for the roof - ordinary plywood cannot be used here. The most suitable brand is FSF plywood. It has the qualities necessary for creating sheathing - fracture strength, ductility, low density, light weight, and is not afraid of fungus. This plywood is resistant to moisture, which means it will not rot. In the process of its production, residues from the processing of coniferous wood are used.

Another good and suitable material for creating sheathing is OSB board, a slightly improved version of the chipboard familiar to many. She's different high level moisture resistance, dense and durable, not afraid snow load, very smooth and does not deform when exposed to moisture. It will ensure that there are no differences in height and will make the sheathing perfectly level. The material is quite simple to install and does not require the use of any special tools.

The sheathing for a soft roof can be made from edged or tongue-and-groove pine boards. The material should have low humidity - no more than 20%. The width of the boards used should be 140 mm. The main disadvantage is the tendency of the boards to deform; due to moisture, they often warp and bulges and cracks form on the surface of the sheathing.

Important! Before using wood in construction, it must be treated with antiseptic compounds, as well as drugs that increase the fire resistance of the material.

Rules for making lathing

The creation of lathing can only be done in compliance with certain rules. Otherwise, the structure will not last long and will quickly deteriorate. And the manufacturer of soft tiles does not provide a guarantee for its material in case of violation of the installation technology.

So, special attention requires determining the angle of inclination of the roof slope. If it is very small and is only 5-10 degrees, then soft tiles need to be laid only on a solid sheathing made of plywood and boards. And in general, in this case, this material is not recommended. If the slope angle is within 10-15 degrees, then the sheathing is made of timber with a cross-section of 45x50 mm and covered with plywood or OSB. The bars are installed in increments of 45 cm. If the angle exceeds 15 degrees, then a beam of the same cross-section is used to create the sheathing, but mounted in increments of 60 cm.

Attention! When calculating lathing requirements, it is important to consider climatic features region - the load that the roof will experience due to snow cover. The load that will be created by the roofing material itself is also taken into account.

Table. The dependence of the pitch of the rafters on the thickness of the material used.

Step, cm	Plywood thickness, mm	OSB thickness, mm	Board thickness, mm
30	9	9	Not used
60	12	12	20
90	18	18	23
120	21	21	30
150	27	27	37

When installing the sheathing, it is worth remembering about the compensation gaps that are left between the elements of the material from which the solid base is created. The gap between sheets of plywood or OSB should be 5-10 mm. If the material swells, it will save the roof from curvature, and the roofing material from damage.

Lathing technology. Design Features

The basis of any roof is the rafter system. They are fixed on the Mauerlat - a support that is mounted around the perimeter of the house and will test maximum load. Therefore, the Mauerlat must be durable and securely fixed. Fixation is done using anchor bolts. If the walls of the house are not built of wood, but of aerated concrete or brick, then it is recommended to additionally fix the anchors with cement.

After installing the Mauerlat, the creation occurs rafter system. Rafters can be made of wood, metal and other materials. Wood is the easiest to work with, it can be easily adjusted to specific dimensions on site, and you don’t have to order it for lifting to the top. special equipment. The rafters are installed in increments, which are determined based on the thickness and width of the materials used for continuous sheathing(if she lays on them immediately). For example, with a board thickness of 2 cm, the step can be 50 cm. The same step can be used when laying plywood or OSB with a thickness of 10 cm. If the step is too large, the base of the roof will bend over time under the weight of the roofing material itself.

On a note! If the sheathing is mounted from a board, then it is important to round its edges in order to avoid the occurrence of unevenness on the surface in the future.

Do not forget that the roof must have ventilation. The gap that is formed between the solid and sparse sheathing is quite suitable as it. If the boards are laid on joists, then it is important to think about how to make vents. Otherwise, condensation will accumulate under the roofing material, which will cause negative impact for all elements included in the roof structure.

Waterproofing too important aspect which should not be neglected. Material capable of retaining moisture is laid on the rafters and fixed with bars - a counter-lattice (sparse lathing) is formed.

Thermal insulation is useful if the house is planned to be used as a residence throughout the year. In the case of temporary country house where they will live only in the summer, thermal insulation may not be useful.

The sheathing materials are fastened using self-tapping screws. Nails are used less frequently. However, regardless of which fastening option is used, the caps must in any case be recessed into the base. Otherwise, the coating on top may be damaged. Fastening is done in increments of at least 15 cm.

Sheets of plywood are laid staggered - their joints in parallel rows should not be in the same place. OSB boards are installed in a checkerboard pattern, that is, seam spacing is also necessary. The joints of longitudinal seams should be located on the battens of the sheathing (counter-lattice).

Important! After the work on creating the sheathing is completed, the lining carpet is laid on a flat base. Only after this the most flexible tiles are installed.

Don't forget about the drip

The protection of eaves and rafters from moisture is provided by a drip tray. Its purpose is to remove moisture from the roof into the drainage system. Thus, this element will protect the wooden parts of the structure from exposure to moisture, the onset of rotting processes, and the development of mold or mildew.

The drip line is fixed on the edge of the roof in a vertical position. Due to this, water from the roof will flow directly into the drain. As a rule, this element is made of galvanized steel, painted in a color to harmonize with the roofing material. It is installed along the entire perimeter of the roof. Fastening is done to the sheathing.

Creating sheathing for soft tiles

Step 1. Taking into account the bearing capacity of the foundation and the shape of the roof, a rafter system is created from boards with a section of 150x50 mm. The elements are installed in increments of 60 cm.

Step 2. A vapor barrier membrane is attached to the rafters from the inside, which will prevent moisture coming from inside the house from affecting the roofing materials. The vapor barrier roll is rolled out parallel to the eaves, the material is fixed by using a construction stapler to the rafters. Individual strips of material are laid overlapping each other. The overlap is 10-15 cm. The membrane is also overlapped onto the walls.

Step 3. Insulation is being laid. Mineral wool, which will be used in this case, has a thickness of 20 cm. This best option for regions of Russia. In general, the thickness of the insulation will vary depending on the climate of the area. The material is laid on top of the vapor barrier membrane. The width of the insulation should be equal to the installation pitch of the rafters. If the material is laid in several layers, then the vertical seams should be spaced apart.

Attention! From the inside, several support boards are nailed to the rafters through the membrane, which will help hold the insulation in place.

Step 4. A counter beam with a cross section of 5x5 cm is installed in increments of 60 cm. Another layer of thermal insulation 5 cm thick is laid between the individual beams.

Step 5. A vapor diffusion membrane is being laid, which will protect the roofing materials from dust and moisture. It is laid on the insulation, the roll of material is rolled out parallel to the cornice. The individual strips are laid with an overlap of at least 10 cm. It is also ensured that the membrane extends 20 cm beyond the contour of the insulated layer of the building. The material is fixed using a stapler. The overlaps are additionally taped with adhesive tape.

Step 6. To ensure under-roof ventilation, a ventilation chamber is created. To do this, counter beams with a section of 5x5 cm and a pitch of 30 cm are installed parallel to the rafters. The beams are attached in a checkerboard pattern so that there is a free gap of about 5-10 cm between them every 1.5-2 m.

Step 7 A continuous base for flexible shingles is created from oriented strand board or plywood. The thickness of the material is at least 9 mm. The slabs are laid staggered relative to each other, leaving small gaps between them - 4-10 mm. The sheets are laid parallel to the cornice.

Step 8 The cornice strips are being attached. They are installed on the edge of a solid base. Fixation is carried out with self-tapping screws in increments of 25-30 cm. Individual elements are installed with an overlap on each other. The overlap must be coated with sealant.

After this, the underlay carpet is laid and the soft roof is laid directly.

Video - Creating a base for a soft roof

The sheathing is one of the most important parts in a roofing system created using soft tiles. Creating a sheathing is not difficult, but it is important to remember all the subtleties of installation, otherwise the roofing material will not last long.

Recently, flexible roofing has begun to be used along with standard roofing materials. It is made from three constituent elements : fiberglass canvas or cellulose, which is the basis.

The second component is filling from modified bitumen, acting as a connecting element.

And finally, the third - stone granulate, which is a sandy coating, painted in various shades. It limits the influence of ultraviolet radiation and precipitation on underlying elements.

Advantages of using flexible tiles:

• Waterproof;
• The elements are completely resistant to biological influences (moss, fungi, lichen, etc.);
• Roof color fastness;
• It has light weight, which greatly simplifies transportation. Thanks to this quality, there is no need to further strengthen the underlying structures;
• The elements are laid out in such a way that the percentage of waste is reduced to a minimum;
• The flexibility of the elements allows the roof to adapt to deformations and irregularities that arise during operation;
• Easy to care for and.

Specifications you can recognize the tiles by.

The construction of a roof always involves the creation of an additional lattice structure, on which further laying and fastening of parts is carried out. It is made of boards and beams located at right angles to the rafters. Depending on what roofing material the sheathing is laid under, you can distinguish several of its types:

• Continuous sheathing step for a soft roof, the gap between adjacent elements is no more than 1 cm. It is used for roofing made of flexible materials.
• Sparse lathing, the elements of which are located at a greater distance. Used for rigid roofing. Most often made from boards.

In addition to the fact that the solid lattice serves as a basis for fastening elements, it also acts as additional sound and heat insulation.

Sheathing for flexible tiles can be divided into:

• Single layer, the elements of which are only plank or block elements laid perpendicular to the rafter legs;
• Double layer, having more complex design. It consists of a base, the structure of which is similar to a single-layer sheathing, as well as a top covering layer of oriented strand board, plywood, planks or tongue-and-groove boards. The elements of the top layer should be located at a minimum distance from each other, perpendicular to the underlying frame or at an angle of 45 degrees, thereby creating a continuous structure. Double-layer lathing is used for soft roofing, as well as for roofs with large rafter pitch.

The structure of the sheathing for flexible tiles

Requirements for the design of sheathing for bitumen shingles:

• Sufficient bending strength, allowing the elements to withstand constant loads from the weight of the coating, as well as snow and wind influences;
• Resistance to mechanical stress;
• The parts must be uniform, without knots, bumps or cracks, exceeding 6 mm;
• Boards and sheet materials must be straight and have no sag.

Base installation

As mentioned earlier, the design of the sheathing for a soft roof can be single-layer or double-layer. Let us consider in detail the installation of elements of each of these options. In turn, it will be laid on the sheathing.

Installation of single-layer lathing for a soft roof

For this type of construction the following materials can be used: Panel board (FSF, OSP-3).

Sheet materials are fastened directly to the joists of the rafter system in a perpendicular direction. Such installation is carried out quite quickly, since large-sized elements are used.

The thickness of OSB for flexible tiles depends on the pitch of the rafter legs:

• 27 mm– for a rafter pitch of 1.5 m;
• 21 mm– for a rafter pitch of 1.2 m;
• 18 mm– for a rafter pitch of 0.9 m;
• 12 mm– for a rafter pitch of 0.6 m;
• 9mm– for rafter spacing less than 0.6 m;

Adjacent elements are stacked with the formation of a 2 mm gap(if work is carried out in winter time, then it needs to be increased to 3 mm). If we neglect this rule, then under the influence of moisture wood materials may swell and swell. All laid elements must be treated with antiseptic solutions, since their moisture resistance is not ideal.

When using FSF sheets, they are secured to the rafters using self-tapping screws or nails, in increments of 150 mm. To select the appropriate length of fasteners you need to use the following formula:

L = h × 2.5;

• L – length of self-tapping screw or nail;
• h – thickness of the plywood sheet.

Installation of OSB sheets is carried out in a similar way. For fastening, in addition to self-tapping screws, can be used spiral or ring nails. The pitch between them should be 150 mm, and if spiral elements are used, it can be increased to 300 mm.

NOTE!

Self-tapping screws and nails must be driven into the sheet material up to the head. In this way, the coating will be better protected from exposure to atmospheric moisture. You can calculate the number of tiles and the sheathing system on our website.

At the last stage, the underlying carpet is laid, on which the soft roof is mounted.

Single-layer sheathing made of tongue-and-groove boards or planks

The basic principle of arranging this type of base for a soft roof is the transverse laying of pieced wooden elements directly on the rafters.

The width of the boards is usually 10-14 cm.

The thickness is selected depending on the pitch of the rafters, since this distance directly affects the required bending resistance of the boards.

The pattern is as follows:

• Rafter pitch from 300 to 900 mm – board thickness 20 mm;
• from 900 to 1200 mm – board thickness 23 mm;
• from 1200 to 1500 mm – board thickness 30 mm;
• For a pitch of 1500 mm - board thickness 37 mm;

Installation is carried out from the lower edge of the slope. In this case, the elements must be placed strictly perpendicular with trays up(to carry out the movement of moisture from rain along the tray to the eaves).

When exposed to moisture and temperature changes, wood changes its geometric dimensions. Therefore, it is necessary to create a gap of 3 mm between the ends of the boards. Fastening is done using nails or self-tapping screws, driven as close as possible to the edge of the product.

Installation of continuous two-layer sheathing

The main difference from a single-layer base is the presence of a lower counter-lattice frame. It is made from boards (25mm × (100-140) mm) or bars (30 × 70 mm, 50 × 50 mm), by placing them on the rafter base at a right angle. The pitch of the counter-lattice boards should be about 200-300 mm.

The next layer is laid with a layer of boards at a 45-degree angle. Between them, as in the case of a single-layer structure made of piece elements, a stabilizing gap of 3 mm is arranged. In addition to boards, you can use plywood or OSB sheets, with or without laying a layer of insulation (for a warm attic).

Installation of combined sheathing step by step:

• Laying and securing thermal insulation between rafter elements;
• A waterproofing film is stretched over this layer and nailed to the rafters using counter-lattice bars (25×30mm). In the case of a cold attic, installation of thermal and waterproofing is not required.
• Sheet materials are secured in increments of 300 mm in places above the rafters, and 150 mm above the counter-lattice bars.

CAREFULLY!

Wood materials must have a moisture content of no more than 20%.

Installation of rafters under a soft roof with your own hands

Rafters - elements load-bearing frame roofs, receptive and redistributing load from atmospheric influences and the weight of the entire roof on the wall structures. In addition, it is the basis for subsequent work on the construction of the upper part of the building.

It differs from the construction of a rafter system for other materials only in the presence of additional sheathing, which provides fastening of small flexible tile elements.

Sequence of installation of the rafter frame:

1. It is being built at a height board template, repeating the design contours of the future roof;
2. The template falls to the ground. In accordance with its outlines, they are installed and secured load-bearing rafter legs;
3. Inside the triangular frame are the remaining elements of the truss (braces, racks, tie rods, etc.);
4. All parts are connected to each other by rigid connections;
5. On load-bearing walls longitudinally Mauerlat is being laid, which is bars 100*150 mm. It is secured with a wire rod or a pin connection;
6. A load-bearing log or timber ridge girder is installed (if the span between the walls is more than 6 m, preliminary installation of additional truss structures will be required);
7. The first truss rises, and installed on one of the ends of the building. Its preliminary fixation is carried out;
8. The second farm is rising, which must be installed on the other end, and also secure using a detachable connection;
9. A rope is stretched between two trusses, with the help of which the vertical installation is checked;
10. The final fastening of the supporting rafter system is carried out using a rigid or hinged connection.
11. The following trusses are installed with a certain step. The rafter pitch for a soft roof should be from 0.6m to 1.5m. It should be taken into account that the larger the number, the smaller the pitch of the rafter legs should be.
12. On rafter legs A single-layer or two-layer sheathing is constructed for a soft roof. almost ready.

Useful video

And now the installation of the sheathing using the example in the video:

Conclusion

Soft roofing is one of the innovative options for finishing the upper part of the building. It is practical and easy to use, and also has high technological and aesthetic performance properties. However, its construction will require a little more effort and time, since you need to take care of installing an additional lattice frame.

In contact with

When buying bitumen shingles you need to remember important detail. Along with this coating, you definitely need to choose a base for the roof. Moreover, there are a number of requirements, only by observing which, the roofing material will retain all its advantages. The flooring under asphalt shingles must be smooth, continuous, clean and dry.

The materials used are moisture-resistant plywood, tongue-and-groove edged boards and OSB-3 oriented strand board. Remember that the manufacturer's proprietary warranty is automatically canceled in cases where the under-roof base does not form an even flooring, and damage or defects in the roof are caused by its deformation (shrinkage, bending of the crack, etc.).

Cheap and cheerful

Relatively inexpensive material still remains wooden plank . This kind of flooring can be done well and correctly, but for some reasons it is quite difficult. Firstly, the boards are usually not the same width, and this can lead to an uneven surface of the base. Secondly, there is a high probability of material deformation during operation due to high humidity lumber. According to the recommendations of flexible roofing manufacturers the relative humidity of the board base should be no higher than 20%. Measure this indicator in living conditions- the task is not easy. In addition, the material may gradually gain moisture during storage, transportation or installation.

When working with such a base, experts recommend using narrow tongue-and-groove boards ( up to 100 mm wide). To prevent their deformation, they should not be pulled together. When fastening, it is necessary to use galvanized (spiral, rough) nails. One of the advantages of wooden flooring is environmental friendliness, since it does not contain harmful chemical impurities and adhesives.

Who is OSB-3?

Oriented Strand Board or oriented strand board marked “3” or “4” (the number means density) is a reliable and convenient material for creating roof decking. Thanks to special technology pressing, there are practically no voids or air pockets inside such slabs. Plates OSB-3 And OSB-4 recommended by experts for several reasons. Their strength characteristics allow them to be used in the construction of pitched roofs in the Russian climate. They're great resist deformation And practically do not warp when exposed to moisture.

When choosing this material, pay attention to several important points. The thickness of the material should be more than 9 mm. Look at the labeling carefully. OSB-3 and OSB-2 boards are practically indistinguishable by eye. The main participants in the oriented strand board market are manufacturers from the USA, Canada and Europe. If roof installation work lasts more than 3 weeks, it is better to choose the third option, since European products are superior to North American ones in moisture resistance.

Durable and reliable

Moisture-resistant plywood - easy to install and quite expensive material. It effortlessly allows you to create a smooth and even surface even on “difficult” roofs.

As in the case of OSB-3 boards, you should pay attention to the thickness - it should be more than 9 mm. Thin plywood can sag as a builder moves across the roof, thereby destroying the adhesive bonds of the material. Its use is justified only when creating complex geometric shapes, for example, spheres or cones. But even in this case, its thickness should exceed 6 mm.

On the Russian market you can buy 3 types of moisture-resistant plywood. FC- moisture-resistant plywood price per sheet from 490 rubles. , which contains urea resins for gluing substances. This material is suitable for interior decoration premises, but not at all suitable for roofing coverings. FSF- plywood with increased moisture resistance. It contains phenolic resins, which are used for gluing substances. Any of the 5 classes of this material is suitable for creating a base for a soft roof. FB- moisture-resistant plywood impregnated with bakelite varnish. Of the 3 types, this is the most expensive and moisture-resistant option.

Despite all the advantages, moisture-resistant plywood has 2 disadvantages. Firstly, the high price. Secondly, it is not environmentally friendly, the main reason for which is the content of phenolic resins. Moreover, the higher the water resistance class, the worse this indicator.

Alternative solution and flat surface

To create a base for a flexible roof, some experts advise using alternative method. Its essence is combining sheet material(OSB-4, OSB-3, moisture-resistant plywood) and board sheathing. A huge advantage of this solution is that it allows for under-roof ventilation in two directions. It should be remembered that, regardless of the choice of material for the roof base, it is recommended to use underlayment when installing over the entire surface of the roof. It allows you to prevent the base from getting wet during work or in case of damage to the tiles during operation, and also partially smooths out surface unevenness (for example, joints between sheets of plywood).

In conclusion, it is worth noting that no matter what option you choose, all materials for creating the roof base must be of high quality and proven. Savings in in this case can lead to the fact that even very expensive flexible tiles will fail in just a few years. Before purchasing, be sure to consult with practicing roofers, for example, on . This will help you avoid possible mistakes.

The article was prepared based on materials from the magazine “Roofs”