The size of suburban areas and the desire of their owners to use the fertile soil layer to the maximum convinces them to make decisions about expansion useful areas in the vertical rather than horizontal direction. It is easier and more profitable to equip an attic above the bathhouse than to attach it to it extra room rest or build a separate house. True, this option will be acceptable only if there is more than 50% of the useful under-roof space with a height of 2.5 m, and if the ceiling above the bathhouse is designed in such a way that you can walk on its upper plane without fear. If the above prerequisites are met, insulating the attic will allow you to turn it into an excellent living space.

• Let's start with the fact that the roof configuration is far from the shape of a classic cube. The insulation will have to be installed on inclined surfaces. And since we are considering insulating the attic from the inside, it is impossible not to take into account the complexity of installing soft and flexible rolled materials.
• Let us remember that the vast majority of the area of ​​the upper fence is roof structure with a rafter system. Its coating is made of extremely light materials with high waterproofing qualities, but also with considerable thermal conductivity. The wooden elements of the sheathing of the rafter structure are laid with gaps that do not form a thermal barrier.

• Let's take into account that in attic floor There is not only a roof surface, but also at least two gables and a valley. Leaving them without insulation or poorly insulating them means reducing all efforts to zero.
• Let's not forget that roofing material that does not allow atmospheric moisture to pass through also prevents the escape of fumes that are natural for a bathhouse and not only for it.
• We will ensure the safe use of living space by insulating the attic roof with materials with the environmental and hygienic characteristics required for home improvement.

Summarizing the above criteria, we will create a unique formula of the requirements that the thermal insulation system being constructed must meet. According to the tasks set for insulation, we will select the material and find out everything technological nuances. For efficient work thermal insulation is necessary to:

• the insulation layer completely covered internal surfaces without “gaps” in a kind of carpet, so that there are no weak points in the thermal insulation system in the form of an unprotected ridge and pediments not covered with insulator;
• the insulating material, resisting the attacks of a cold atmospheric front from the outside and a warm, humid front from the inside, was protected from condensation formed as a result of their confrontation;
• on outer surface the thermal insulation layer did not accumulate moisture that was not allowed out by the waterproofing roofing coating, so that excess moisture was removed through the ventilation ducts;
• lightweight roofing insulation was equipped with wind protection, preventing heat from blowing out of the attic on windy days;
• the material is suitable in terms of technical, technological and sanitary-hygienic parameters.

The listed requirements are a detailed answer to the question “how to properly insulate an attic.” If the thermal insulation system meets all conditions, then it will serve for a long time and work efficiently.

Choosing the right insulation

From a technological point of view, slabs are best suited for creating a thermal insulation system from the inside. Using a material that holds its shape, it is easier, faster and more convenient to insulate the attic with your own hands with a minimum number of additional fixing devices. For their correct installation, longitudinal bars with dimensions allowing to ensure ventilation gap. The outer plane of the bars must coincide with the outer plane of the elements rafter system, the internal plane of the heat-insulating material must coincide with the internal plane of the rafters.

Note. If the power of the selected insulation is greater than the width of the rafters, each element of the rafter system will have to be nailed or installed with screws additional beam. Wooden additions must be treated with an antiseptic before installation.

In any case, both with sufficient and insufficient rafter width ventilation space must be left between the insulation and roofing material.

Indicators of the thermal properties of the material determine the climatic characteristics of the region. The collection of building regulations numbered 02/23/2003 will help you find them out. According to the indicator specified in SNiP, the material must be selected.

• Styrofoam - budget material and a convenient way of insulation. Lightweight slabs will not be difficult to install; the thermal insulation system will not significantly increase the weight of the roof. However, the weak ability to conduct steam and its attractiveness as a tasty dish for mice make us think about whether it is worth insulating the attic with polystyrene foam.
• Mineral wool is also a convenient and democratic option. The slabs, cut to a size a couple of centimeters larger than the gap between the rafters, are easy to install. Before installation, the insulation element must be slightly compressed and placed in the required location. Having straightened out, the elastic mineral wool will “sit” firmly in its nest. Glass wool can be used as an almost equivalent alternative.

• Expanded polystyrene is usually laid on top of the rafter system, forming a ventilation gap by installing a counter batten between the insulation boards and the roofing. It is not suitable for insulating a roofing system from the inside, but can be used for insulating gables.
• Polyurethane foam - easily applied to surfaces of any complexity by spraying. A contractor with a portable installation that supplies foamed insulating material under pressure can work on planes with any slope. Insulating the attic with polyurethane foam will create a monolithic layer without the slightest gaps. In addition, there will be no need for a vapor barrier layer to protect interior decoration from exposure to condensation.
• Ecowool is a heat insulator from the category of sprayed materials. Its properties are similar to wood; it contains an antiseptic that prevents damage to the insulating layer and the wood in contact with it. Just like the previous analogue, it creates a continuous cover that does not sag during many years of use. To insulate ecowool, it will be necessary to install false ceiling and install a sheathing to attach vapor barrier material to it.
• Foil materials that work not only as insulation, but also as a mirror reflector of heat tending to escape. In order for the foil heat insulator to perform its job perfectly, during installation you need to unfold it with the aluminum layer inside the room and leave a distance of 5 cm between it and the vapor barrier layer.

The list is quite sufficient so that there is something to focus on, but the most popular materials for insulation from the inside are recognized as mineral wool. Spraying with polyurethane foam is popular, but not available to everyone due to the lack of equipment, which, however, can be rented for a while in construction organization. All that remains is to figure out how to insulate the attic with your own hands and get excellent results.

What should a proper constructive pie look like?

Exaggeratedly, the thermal insulation system represents the following constructive pie, if you start listing the layers from the side of the space being developed:

• Cladding made of plasterboard slabs.
• Vapor barrier layer, preferably a membrane type option. It is a continuous shell created from strips laid with a 10-centimeter overlap roll material. The canvases are secured at horizontal and vertical joints with special adhesive tape.
• A sheathing that performs three functions. The slats attached across the rafters hold the insulation, serve as the basis for fixing the vapor barrier and form a ventilation space, which is especially necessary when using foil material.
• Insulation laid in one or several layers depending on the thermal effect created. When insulating the attic from the room side, it is mounted between the rafters.
• A waterproofing layer that protects the insulation from getting wet, which results in a decrease in thermal properties.

Note. Builders who thoroughly know how to insulate an attic strongly advise leaving a ventilation gap between the thermal insulation material and the waterproofing. According to technological standards, its absence is considered a grave mistake.

• Another counter-lattice that creates a ventilated space between the waterproofing and the roofing material. Ventilation in this case is necessary to remove moisture accumulating on the waterproofing membrane. To remove moisture, holes are provided at the base of the slopes and in the valley area. The width of the gap for ventilation is determined by the roofing material. If the roof is covered with tiles, slate, corrugated sheeting or corrugated ondulin, it is enough to leave 25 mm, if flat material without profile relief you need to leave 50 mm.
• Windproof vapor barrier equipping the ventilation space. It is needed to retain heat in the event of active ventilation in the ventilation gap. It is laid above the rafter legs, secured with slats, on top of which the roofing covering is mounted.

By insulating the attic with your own hands, observing all the details, the owner of a bathhouse with an attic will provide himself with a comfortable living space, eliminating the need to build on summer cottage house. For arrangement mansard roof There is no need to obtain permits or seek the consent of neighbors for housing. But the benefits and economic effect obvious.

So that the roof meets everyone's needs architectural features modern buildings, it is often made in the form of structures from many multi-pitched roofs. Geometrically complex frames of the rafter system have a large number of junctions of pitched surfaces forming internal corner roofs. Such areas in a wooden roof structure are called valleys. Another name for this element is a valley or valley gutter. Having a v-shape, the roof valley actually plays the role of a gutter through which water flows are directed and removed. Proper installation of this element is of great importance, since installation errors can lead to leaks, damage to the insulation and additional repair costs.

Valley design diagram

The valley is one of the most important and complex elements of the roof structure. The interface between adjacent slopes is subject to severe climatic loads during operation. When it rains, water flows down it from neighboring slopes, and in winter snow accumulates here.

A properly installed valley not only protects the house from bad weather and precipitation, but also extends the life of the roof.

Typically, the valley consists of a decorative upper strip that covers the junction of two slopes, and a lower gutter, which is located under the roofing.

The number of valleys depends on design features roof, as well as the presence of additional roof windows.

Depending on the design features of the roof, the number of valleys installed will vary.

The design of the valley involves the construction of a base in the form of a continuous sheathing, on which a layer of waterproofing is laid, as well as the presence of a lower and upper element. The lower valley strip serves as a gutter, and the upper element serves as a decorative detail covering the joints of the slope. Most often, these roofing elements are made of metal. The most quality material for the manufacture of valleys are steel sheets with applied polymer coatings and special sprayings. In some design options, the upper part of the valley is not used.

To improve the waterproofing properties of the lower valley, its upper flanges can be sealed with self-expanding porous material

Depending on the angle formed at the junction of the roof joints, there are three types of valleys:

The design of the rafter system, which serves as the basis for installing the valley strips, depends on the intended type of roofing. In this regard, there are several types of lathing for laying valley planks:

1. Continuous sheathing is used during installation soft roof. In this case, the valley is made in the form of a continuous coating of waterproofing layers. Installing a valley in this way is the easiest.
2. If slate, profiled sheets or tiles are used as roofing for a gable roof, the sheathing will have a completely different look. To install it, use 2 or 3 edged boards, which are mounted along the joints of the roofing in increments of 10 cm.
3. Lathing with additional elements. When using metal tiles, intermediate strips can be installed to the main battens of the sheathing.
4. The wooden base for the ondulin is made of two boards 10 cm wide, which are mounted in increments of 15–20 cm. Such a base will prevent the valley from sagging.

Video: arrangement of valley and junctions

Valley installation sequence

Installation of the valley is carried out in the following sequence:

1. Before installation begins, a drip line is installed along the entire length of the eaves overhang to drain condensate from the under-roof waterproofing.

   The drip cap is made of the same material as the main roofing covering

2. On both sides of the bone rafter with a gap of 5 cm from its edges, horizontal counter-lattice bars are nailed. The lower ends of the bars must be sawed flush with the eaves overhang.
3. There are increased requirements for waterproofing in the valley area. Three layers of diffusion membrane are laid here. Its task is to protect the underlying structures and thermal insulation materials from moisture, but not to prevent the escape of water vapor. The first layer of membrane is laid out along the valley on top of the horizontal counter-lattice. The film inside the counter-lattice forms a kind of groove that protects the wood from getting wet on the side in the event of under-roof condensation. The membrane is attached using staples to the top and side edges of the planks. Then the membrane is cut along the edge of the drip and counter-lattice.

   The waterproofing material protects the counter-lattice strips from getting wet on the side and is attached to them with a construction stapler.

4. Next, the diffusion membrane is laid out along the slopes onto the rafters according to pre-made markings. Laying waterproofing on slopes is done in a pigtail, that is, alternately on both sides of the valley. In this case, the membrane is transferred through both horizontal counter-battens and cut off behind its opposite edge. The membrane is also fastened to the slopes using a stapler on the side and top edges of both horizontal counter battens. The joints of this waterproofing barrier can be sealed using double-sided tape.

   When gluing the membrane, it is necessary to make an overlap of at least 10 cm and glue it with double-sided tape

5. To prevent the membrane from flapping against the drip tray from the wind and from fraying over time, it is necessary to glue it to the edge of the drip tray with double-sided tape.
6. On top of the waterproofing, valley board bars are packed, which form air gap for ventilation of the under-roof space and removal of condensate from the film.
   

   A gap is left between the bottom valley strip and the waterproofing film to drain condensate

7. Laying the membrane from the opposite slope, as well as fastening it with brackets to the horizontal counter-lattice and gluing it with double-sided tape occurs in the same way.
8. After both adjacent slopes and the valley are covered with a membrane, the filling of the counter-lattice is completed on them and the installation of the sheathing bars begins. Installation of the lower sheathing along the eaves overhang is carried out flush with the ends of the counter-lattice.

   Wooden sheathing laid on counter-lattice bars is necessary for ventilating the under-roof space and for attaching the finishing coating

9. In the valley area, markings are made on the lower planks of the sheathing at an angle for precise joining with each other. A ventilation strip is installed along the entire eaves to protect against bird penetration.

   The bottom battens of the sheathing in the valley area are trimmed to form an even joint

10. The ends of the sheathing on the side of the gable overhang are covered with a flap of membrane folded up, which is fixed to the bars with a stapler. A frontal board is placed on top of it. If this is provided for in the project, brackets for attaching gutters are installed along the entire eaves overhang.
11. In the valley area, in the middle between the rows of sheathing slats, additional bars are packed, which support the gutter, preventing it from deforming under the weight of snow. At the same time, thanks to the increased sheathing, the space under the valley groove is well ventilated. In the presence of drainage system a plastic overhang apron is installed. Its task is to prevent water and snow from getting into the ventilation gap between the tiles and the waterproofing.

    To counteract snow loads, a thick sheathing is installed under the lower valley strip

If there is no drainage system, installing an eaves apron is not necessary.

Video: installation of a valley on a metal roof

Connection of two valleys on a slope

The installation process at the junction of two valleys is carried out as follows:

1. If the design provides for a junction of valleys below the ridge, then the gutters on both sides are trimmed for a tight fit and secured with self-tapping screws. The junction of the gutters is carefully sealed with sealing tape along the entire length, profiled along the edges and rolled with a roller.
2. The valley strip in the upper part is attached to the sheathing with brackets. Top corner The joint is formed by hand, and the flange is pressed against the surface of the grooves.

   To prevent moisture from penetrating into the under-roof space, bends are made along the edges of the valley planks.

3. The flange is completely bent inward along its entire length, while force can only be applied in places above the sheathing. Along the entire length of the valley groove, foam rubber strips are glued on both sides. They protect the under-roof space from precipitation and dust. The lower edge of the foam strip should be on the overhang aerial element. If foam strips were not used for some reason, water, snow and dust will constantly get under the roofing, thereby reducing the life of the structure.

   Foam strips must be installed to protect the space under the valley strip from water, snow and dust

4. Roofing material is laid on both adjacent slopes in the direction from the gable overhang or valley ridge, covering the groove as much as possible. To ensure unhindered drainage of rainwater and snow removal along the valley gutter, the covering on both sides is trimmed at the same level. The overlap of the trimmed tiles on the valley groove should be from 13 to 15 cm or 8–10 cm from the center of the bottom strip.

   Sheets of metal tiles are cut so that they extend onto the bottom bar of the valley by 13–15 cm

A smaller overlap will lead to the foam strip being destroyed due to exposure to solar radiation, and a larger overlap will complicate the installation of the tiles.

The cutting line is applied with a dye cord along the marks located at the top and bottom of the valley, and is marked on both sides of the groove.

Video: valley with access to a slope on a metal roof

Features of fastening elements of the valley assembly

The valley node looks like a concave angle between two roof slopes. To fasten this roof element, roofing screws are used, which are equipped with a rubber or plastic washer. The washer performs several functions:

• protects the surface of the roofing material from scratches and damage;
• serves as a waterproofing layer between the self-tapping screw and the hole in the roof, hermetically closing all cracks.

The rubber washer provides soft pressure on the screw and waterproofing of the hole

When installing the valley strip, an overlap of at least 10 cm must be made.

To better seal these roofing elements, it is necessary to use sealing tape.

The lower valley strips are mounted directly to wooden sheathing using clamps fixed with nails or self-tapping screws. The upper element of the valley must be screwed with self-tapping screws to the metal tile. It should be noted that the screws for fastening the upper valley should not rest against the lower gutter. The gaps between the roofing and the gutter sheets must be filled with foam rubber sealant.

Clamps secure the bottom strip of the valley without damaging its edges

When installing valley units, you should pay special attention to the quality of the sheathing. It is recommended to install the lower gutter on a continuous sheathing, the width of which should be no less than the width of the valley itself.

Installation of valley nodes is carried out as follows:

The brackets should be attached not to the regular sheathing, but to the thickened sheathing, otherwise they will interfere with the even laying of the tiles.

The upper groove is laid on the underlying one with an overlap of at least 10 centimeters. When laying, it is necessary to align the transverse ribs of the gutters and secure subsequent grooves in the same way as the first.

When installing a valley from several planks, it is necessary to make an overlap of 10 cm

Installation of overhang aero element

An overhang aerial element is installed to provide additional support for the bottom row of metal tiles, as well as to prevent birds from entering under the roof.

If the discharge is larger, it will hold debris and fallen leaves in the gutter, and also prevent snow and rainwater from sliding.

Strengthening the valley

The functionality of the valley is directly related to the quality of its foundation. To strengthen the valley, it is better to use continuous sheathing.

1. A waterproofing layer is installed along the entire length of the base. The best option for strengthening gutter nodes is to use a valley carpet. This protective covering is made of non-woven polyester material impregnated concrete mixtures with the addition of modifiers. A coating of basalt crumbs is applied to the upper side of the valley carpet, and its lower part is covered with sand granules.
2. The waterproofing material is fixed using special stickers or nails. If the carpet is nailed, the distance between them should be about 20 cm.
3. The lower valley elements, roofing, seals and decorative parts are installed.

To strengthen the valley nodes, instead of standard waterproofing, non-woven polyester materials can be used

Installing polyester fabric with bitumen impregnation allows you to solve a number of problems:

• provide reliable protection for internal kinks of the structure and other places most vulnerable to moisture penetration;
• create a shock-absorbing layer that will soften the load from snow;
• improve the aesthetic qualities of the roof;
• completely eliminate leaks.

Trimming tiles when arranging a valley

If the valley is installed on a tile roof, trimming of the roofing material elements is often required:

1. First, a rough fit is performed, and then the final marking and cutting of the tiles is carried out exactly along the line marked on the valley groove.

   Trimming the tiles must be done on a machine with a circular saw.

2. A tile spike that hits the valley is knocked off or cut off so that it does not crack at the groove.
3. The foam strip under the tiles should be trimmed - this allows you to immediately lay the roofing evenly, without waiting for it to push the strip under its own weight and fall into place.
4. A hole for the self-tapping screw is first drilled in the trimmed tile so that it does not fall into the groove.
5. The prepared roofing element is installed in place and secured with a self-tapping screw.

   All laid elements must form a straight line parallel to the axis of the groove

6. Sometimes when marking, it is clear that after cutting off some elements, a small triangular fragment remains, which is difficult to secure. This happens if the cut line falls on the right edge of the tile, then the cut line is shifted by 5 cm, and half-tiles are used nearby. It is installed instead of the usual row one column from the trimmed one. The consumption of half roofing elements is one piece per two rows on each side of the valley.

   Half tiles add the missing roofing fragment if in this row most of the surface of the last covering element falls under trimming on the valley

7. The prepared trimmed tiles are laid in place and fixed with a self-tapping screw. The tile from the top row moves down and presses the trimmed element.
8. The rest of the roofing material in the valley is laid in the same way. When laying on a ridge, the outermost ridge tiles that extend to the junction of the valleys are cut along the same line as the tiles located in rows on the slope.
9. The upper cut of the outermost ridge tile is covered with a special tape for junctions. The valley installation is complete.

   Corrugated tape is convenient and effective material for sealing protruding parts of the roof

You cannot fasten tiles through the valley groove, as precipitation will flow under the roof where the self-tapping screw passes.

Video: installation of ceramic tiles - valley formation

Errors when installing the valley

Installing a valley gutter requires care and skill. Since this roofing element carries a large amount of rainwater, the slightest mistake during its installation can lead to serious problems and additional costs. The most common mistakes when installing a valley are:

1. Trying to cut tiles directly at the valley using a grinder. This often leads to damage to the already secured groove. In addition, it is very difficult to achieve an even cut line along the entire length of the valley, so the valley and the entire roof will look sloppy, and water drainage and snow removal will be difficult.

   If the tiles are cut unevenly, the roof will have a sloppy appearance, and water and snow will flow off it intermittently

2. Fastening the groove with nails along the entire length.
3. Installing valley strips from the ridge to the bottom edge. In this case, the lower bar will cover the upper one. At the junctions of these elements, moisture will get inside the roof rather than flow down.
4. Narrow sheathing or lack of additional slats. This mistake will cause the weight of the snow to deform the valley. As a result, cracks and gaps are formed through which moisture can penetrate.
5. Twisted or insufficiently tightened screws. In the first case, the roof covering is damaged, in the second, moisture will penetrate under the screw.

   If the screws are not tightened correctly, water will flow into the under-roof space, contributing to the destruction of the rafter system.

The process of installing a valley requires special knowledge and construction skills. Therefore, installation of this roofing element better to trust experienced specialists. In this case, errors that lead to serious problems will be eliminated.

Increasingly, the roof has not only functional purpose. Often this element is the highlight of the building. Such roofs have many planes that are connected under different angles. Some connections - with positive angles - are designed in the form of a ridge, some - with negative angles - in the form of valleys. To ensure that the attic is always dry, the roof valley must be done correctly.

Valley roofs

On roofs of complex shapes, when protruding dormer windows are installed, sharp corners are formed. They are obtained at the junction of two slopes. The junction is called the valley, and the roofs are called valleys.

Roofs of complex shapes look very decorative and are a decoration of the building, but their design and installation is not an easy task - connecting planes is not easy. Due to the design features, these areas of the roof bear a heavy load: there is always a lot of snow and water. Therefore, the sheathing is made reinforced, and waterproofing measures are much more serious than on the rest of the surface.

Features of rafter systems

Rafters from different slopes in the valley can be connected at different angles (depending on the shape of the roof). At the junction, a rafter leg is installed, to which the rafters from the slopes are attached. For a short length (up to 2 m), it is enough to fasten them on nails (2 on each side); for a significant length, the joints are reinforced with metal plates.

Rafter connection

In places of greatest load (in the widest place), the valley rafter leg is supported from below by a jib.

Lathing

At the junction of two roof slopes, reinforced sheathing is required, and its design depends on the type of roofing material:

We have provided typical requirements and sizes, but some manufacturers may have specific requirements. When purchasing roofing material, you will be given instructions that will describe the entire installation process, requirements for the sheathing, and other technical issues. It is clear that you must adhere to their recommendations.

Valley device

There is no particular point in talking about the device in general, since each roofing material has its own characteristics. Therefore, we will consider the most popular ones separately.

On a metal roof

As already mentioned, lathing is done twice as often under the metal tiles at the junction of the slopes. The bottom plank of the valley is laid on this sheathing - this is a galvanized sheet with a fold line in the center and sides along the edges. This element belongs to the accessories and is painted to match the base material. It comes in two-meter pieces.

Metal roof valley

Installation of the valley strip begins from the bottom. The edge of the element extends slightly beyond the roof overhang, is cut 20-30 mm below the overhang, and a flange (side) is formed from this “remainder”. Please note that the valley strip should end behind the overhang; if there is a drain gutter, then above it. If it is made shorter than the overhang, then water will flow into the roof.

The next sheet is laid on top, with an overlap of 20-30 cm, the joint is coated with sealant (you can bitumen mastic coat the entire overlap). Lay as many sheets as necessary, cut them off near the ridge and secure them.

There are two ways to attach the valley sheet

When constructing a valley, the main task is to ensure tightness. From this point of view, the second fastening option is more correct - it leaves no holes, even if they are covered with a rubber gasket.

One more thing. The bottom bar should have sides on both sides, preferably more than 2 cm in height. They are needed so that water flowing from the slope cannot get under the metal tiles.

A sealing tape is glued to the fixed strip, at a distance of about 20 cm from the bend. It comes with self-adhesive tape. Before installation, the protective coating is removed and the tape is glued. Next, metal tiles are laid, which are cut so that the center of the valley is 60-100 mm. Manufacturers do not recommend placing the cuts closer to the center.

Attach the sheets to the sheathing in regular places- in the lower part the oxen are 20-30 mm below the step. The distance from the fastener to the bend is at least 250 mm.

After fixing the metal tiles, the roof valley is ready and can remain in this form. But appearance Not everyone is happy with cut sheets. In order to close them there is decorative overlay, which is called the upper valley. It performs a decorative function - it covers the cuts; quite often it is simply not used.

Features of the valley outlet above dormer window watch in the next video.

Made from corrugated sheets and slate

Under these materials, several boards are laid lengthwise in the valley. A strip of waterproofing is fixed to them, which is then connected to a waterproofing membrane fixed to the slopes. The overlap should be at least 10-15 cm, the joints are connected using double-sided tape.

In this case, the sealing tape can be supplemented with sealant. A strip of sealant is applied on both sides of the inflection point of the roof. After installation of the roofing material, a large amount of water remains in the wave protrusions. free space. Water, snow, and debris can get there. To prevent this from happening, fill the gap with sealant, applying it in layers.

In the case of a profiled sheet, there are several options for designing the valley:

Open or closed type You choose the connection of the slopes, the structure of the entire pie remains the same. Only the method of cutting the corrugated board changes.

Roof tiles

The structure of a valley roof made of tiles is exactly the same as in the case of a profiled sheet. The difference is that continuous lathing should be larger - at least 35 cm wide on both sides of the joint. The fastening of the tiles in the valley has its own peculiarities - some fragments are cut so much that it is impossible to fasten them with a standard lock. Then a hole is drilled in the top of the tile and a soft, acid-resistant wire is threaded through it. Drive a nail into the sheathing, twist a wire onto it and fix the tiles in the required position.

The second option for constructing a valley with tiles.

Ondulin

In the case of ondulin, the sheathing for the valley is not solid, but two boards located at a distance of 15 cm from one another, symmetrically relative to the center of the valley. A special gutter is placed between them.

Installation starts from the bottom and moves up. The first sheet of the valley gutter is laid flush with the edge of the roofing material, and the shape is corrected. They are nailed to the sheathing from the top side. The next sheet is laid with an overlap of at least 15 cm.

After the entire gutter is laid, the installation of roofing sheets begins. First, they trim with a margin - the mark is placed 5-6 cm further than necessary. Cut along the intended line (with a jigsaw or grinder). Place it in place, mark the exact cutting line - along the protrusion on the gutter. Cut it off a second time and put it back in place. Since the ondulin sheet weighs little, all operations are easy to perform.

The laid sheet is secured with special roofing nails with a head painted to match the coating. It is necessary to fasten it into each wave, retreating as far as possible from the midline of the valley.

Installation of a valley on a roof made of Ondulin is available in video format.

Tin roofs

In private housing construction, this type of roofing material is rare, however, there are such roofs. The tin roof valley is connected manually, using a mallet and a special tool.

Increasingly, developers are choosing unusual roofs for houses, for example, hip or hip roofs. To arrange such structures, it is necessary to use additional elements. One of them is the valley, which is designed to prevent moisture and debris from entering the under-roof space.

What is a valley

The valley is an additional roof element, which is located between two planes of the slopes at the point where they break. Installed where parts of the roof form a negative angle. Essentially, this is a gutter that helps excess water drain from the roof, thereby preventing it from getting under the roofing material.

Endova performs protective and decorative functions

Valleys should be placed on all problem areas of the roof. The more kinks the roof has, the more of these elements will need to be used.

Types of valleys

There are two types of valleys:

It is the lower valley that performs all the main protective functions, ensuring tightness of the joints. The top one serves exclusively for decoration.

There is another classification of this additional element:

• open - can be used on roofs with small angle slope, the joints of the slopes have a gap, under which the valley itself is located, requiring mandatory waterproofing;
• closed - mounted on roofs with an acute angle of contact between the planes of the slopes, while the joints are tightly connected to each other;
• interlaced - similar to a closed valley, it has several interlaced sheets of roofing material on top.

The choice of valley type depends on the roof structure, the angle of the slopes and the roofing material used.

Each type of valley has its own advantages and disadvantages. For example:

• open can provide rapid drainage of any amount of water and melted snow, does not require much time and a lot of tools for installation, but is not always visually attractive;
• A closed valley, including an interlaced one, has a presentable appearance, but takes a long time to install.

Which material to choose

There is no particular variety of materials for making a valley. Regardless of the roof covering, this element can be made of:

• galvanized steel;
• metal sheet with polymer coating.

Most often, preference is given to the second material due to its higher strength characteristics and long service life.

Endova - a groove located between two slopes, which facilitates drainage excess water from the roof

There are certain rules for choosing a roof valley:

• to equip the weakest points, it is recommended to select elements with a sufficient level of galvanization, which will ensure a high degree of tightness of the joint for a long time;
• sheets for the valley must be stronger than the roofing;
• When laying metal tiles or corrugated sheets coated with polyester, it is recommended to choose a valley with a polyurethane protective layer.

Video: internal structure of the valley

DIY valley installation

The valley must be installed in the following order:

1. Carry out preparatory work. At this stage it is necessary to arrange a continuous wood flooring at the junction of two slopes, the presence of gaps is not important. For this purpose, you can use an edged board, which must be coated with antiseptic agents. Its width should be more than 30 cm, and its thickness should correspond to the same parameter as the counter-lattice. It is recommended to additionally lay a sealant on both sides of the joint line between the roofing material and the internal valley to prevent water from entering under the roof. The valley carpet, which is made of polyester fabric impregnated with bitumen, with a coating on both sides, also has waterproofing properties. This material can be fastened with galvanized nails with a wide head.
2. Bend the side parts of the inner valley; the bend angle should be 90°. Shape the edges along the timber.

   The valley groove must be fixed to a solid wooden flooring

3. Bend the inner valley along the central axis. The bend angle of the inner valley must be greater than the angle of the outer valley.
4. Lay the grooves of the inner valley. You need to start work from the top. If necessary, the part can be trimmed or extended. In the first case, you need to step back 3–4 cm from the gutter, in the second, you need to provide an overlap of 10–15 cm. In no case should you forget about the overhang from the edge. It should be about 8–10 cm.

   The lower valley is laid on a solid wooden flooring

5. The sides of the valley in the overhang areas must be bent inward.
6. Secure the groove. This can be done using 2.8x25 mm nails. Leave about 2 cm from the edge. The groove must be nailed directly to the flooring. The distance between the fasteners should be 30 cm.
7. Additionally glue protective stripes made of self-adhesive material, which is impregnated with waterproofing compounds, at the joints of the internal valley with the flooring. They are able to protect the under-roof space from moisture and debris.

   Valley waterproofing is needed when arranging roofs with a small angle of inclination

8. Now you can install the sheathing and roofing material.
9. An external valley is installed on top of the roof. It is fixed with special roofing nails or self-tapping screws. If it is necessary to build up parts, the parts must be laid with an overlap of 10–15 cm.

Video: installation of the lower valley with access to the slope

There are some nuances of valley installation that must be taken into account:

• It is worth performing enhanced waterproofing of the valley only if a large amount of water accumulates in this place, for example, on roofs with flat slope angles;
• sheets of roofing material that are laid in the direction from the slope must be placed with the same overlap, and the fastening must be as reliable as possible;
• When building up, overlaps in the valley are recommended to be additionally sealed with a special waterproofing tape;
• the sheathing at the valleys must be continuous.

The valley is one of the most important additional elements, since it provides protection for the weakest points of the roof. Correct installation of the part will increase the level of tightness of the joints of the slopes and the service life of the roof.