Roof with valley rafter system. What is a roof valley? How to attach a roof valley

Increasingly, the roof has more than just a functional purpose. Often this element is the highlight of the building. Such roofs have many planes that connect at 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.

What is a valley

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. Because of 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.

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

A support is placed at the bottom at the widest point

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

Under the metal tiles in the valley, intermediate strips are installed - in the middle between the main ones. That is, in this place the step is twice as small. The length of the additional strips must be greater than the width of the bottom valley strip.

Lathing is done twice as often

For corrugated sheets, slate and ceramic tiles, two or three boards are needed on each side

Under the ondulin there should be a gap of 15 cm between the two boards

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 and requirements for the sheathing, etc. technical points. 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 coat the entire overlap with bitumen mastic). Lay as many sheets as necessary, cut them off near the ridge and secure them.

There are two ways to attach the valley sheet

special screws closer to the edge;
with clamps over the side.

Fastening to the side with clamps

When constructing a valley, the main task is to ensure tightness. From this point of view, the second fastening option is more correct - after it there are no holes left, 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. Removed before installation protective covering and the tape is pasted. 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.

The sheets are attached to the sheathing in the regular places - in the lower part of the oxen 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 a decorative overlay, which is called the upper valley. She performs decorative function- covers the cuts; it is simply not used quite often.

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.

Installation of a valley on a roof made of corrugated sheets

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 installing the roofing material, a large free space remains in the projections of the wave. 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. This is when corrugated sheets are cut at a distance of 60-100 mm from the bend line. In this case, the bar and cuts are visible. To close this “economy”, a decorative gutter is laid on top of the roofing material, covering the cutting lines. It is attached to the sheathing with nails.

Open valley made of corrugated sheets

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.

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 the continuous sheathing must 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.

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.

A special gutter is placed between the padded boards

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.

The upper fragment of the gutter overlaps the lower one by 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.

Ondulin is trimmed twice: first roughly, then precisely

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.

Fastened with special nails

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.

Roof valley: installation, do-it-yourself installation, photo, video

How to properly make a roof valley from metal tiles, corrugated sheets, ondulin and ceramic tiles. Rules for constructing valleys, work order.

Roof truss system: device features

When building a private house, bathhouse or utility buildings requires a special approach rafter system roofs. It is important to perform the calculations correctly and prepare high-quality material for installation.

Design of truss structure

The calculation of load-bearing structures in construction is usually performed using the limit states method, i.e. at the moment of loss of resistance by the structure under the influence of external loads up to destruction or unacceptable damage.

The rafter system reaches its limit state if:

the strength of the structure is completely exhausted and it collapses;
Deflections of the elements of the supporting frame provoke unacceptable violations in the nodes of the rafter system, and further operation of the roof is impossible without repairs.

According to building codes, the maximum permissible deflection of a rafter leg or tie is 1/200 of the length of the element. To ensure high reliability of the structure, it is recommended to design the roof taking into account the maximum permissible deflection of 1/250 of the rafter length.

The calculation of the roof truss structure is carried out taking into account the maximum loads from the side:

own weight;
wind pressure;
snow weight;
the weight of people servicing or repairing the roof (the load from a person is usually taken as 80 kgf/sq.m).

To obtain information on the basis of which calculations are made, it is necessary to have:

SNiP for roofing structures;
table for calculating the cross section of the rafter leg;
table of cross-sections of rafters;
climate map of the region (determination of wind and snow load).

The cross-section of the timber from which the elements of the rafter structure are made is calculated using a special formula, which takes into account the length of the rafter leg, the pitch between the rafters, and the resistance of the selected type of wood to external loads.

Tables for selecting sections of elements are used when designing simple roofing structures. Developing a roof project of complex shapes requires a professional approach.

Knots of the rafter system

The reliability of the truss structure is influenced by the following factors::

correct choice of rafter system configuration;
strength of connections in structural units;
accuracy of engineering calculations when designing a roof;
correct choice and quality of materials;
installation quality.

The type of rafter system, the presence of certain nodes of elements is dictated:

designed roof shape;
dimensions of the overlapped space;
the presence and location of internal supports or load-bearing walls.

When building houses with a usable attic or attic floor Rafter structures with layered rafters are usually used. Their main nodes include:

support unit for rafter legs;
ridge knot;
“rafter-strut-post” assembly;
“beam-post strut” assembly, etc.

When designing, it is important to immediately decide on the methods of fastening the elements. The choice depends on some of the characteristics of the lumber, as well as the preferences of the people conducting construction work.

Key stages of roof construction

Installation work begins after the preparation of the project, which indicates all the dimensions of the elements and their relative positions, as well as the principles of connection. In addition, you should purchase and bring the necessary Construction Materials, tools, fasteners, etc.

Construction principles pitched roof, in general, do not depend on its configuration. The work technology includes the following stages:

Laying the Mauerlat. The support beam is laid on waterproofing (roofing felt or other moisture-proofing material), which protects the wood from rotting. To fasten the Mauerlat to the wall, wire embedded in the masonry can be used, or clamps can be used to attract the timber to the anchors in the wall, but preference should be given to studs mounted in a monolithic concrete beam.

The length of the free end of the studs must exceed the thickness of the mauerlat beam by a distance that allows the nut to be screwed on. The studs can be staggered (but not necessarily) with a pitch of at least 2 meters. To prevent the stud from being pulled out of the concrete, its recessed end should be bent.

Installation of front (outermost) rafters. When building a roof truss system with your own hands, it is very important to install the main rafters strictly vertically and at the same level; the correctness of the planes of the slopes and, accordingly, how evenly the load on the roof will be distributed depends on this.

Depending on the chosen roof configuration, at this stage a ridge girder is also installed, which must be strictly horizontal. The purlin rests on special vertical posts or is attached to the gables. If mounted hip roof, the key point is the installation of diagonal rafters.

Features of a roof with a valley

The construction of a roof truss system of complex shape (multi-gable roofs) requires the creation of connections for ridges and slopes. The planes of the slopes may have different geometric shape: triangle, rectangle, trapezoid. The endova is the junction of the slopes with the formation of a negative angle.

In the house plan, roofs with valleys look cruciform, T-shaped or L-shaped. These are the two main ways to create roof junctions. At the design stage, a roof plan (top view) is drawn up, taking into account attic and dormer windows, all junctions, roofs over terraces or verandas, indicating all linear dimensions. The general plan of the roof is divided into rectangles and squares; the main rooms and extensions are indicated on it.

On the roof plan, the main purlins should be indicated, and in the perpendicular direction, the secondary purlins over smaller rooms should be indicated. Then lines are drawn connecting the corners of the roof above the secondary rooms with the corners of the main roof. These diagonal lines indicate the location of the valleys - the internal corners formed by the junction of the slopes.

When installing a rafter system, the valleys at the joints of roofs of the same height (i.e. if the ridge girders are located at the same level) are diagonal rafters, resting with the upper end on the ridge girder and the lower end on the mauerlat. The installation of such rafter legs is carried out in the same way as the installation of diagonal rafters for a hip roof.

Depending on the size of the extensions, the corners roof slopes may have different meanings. The geometry of the roof can be changed by shortening the size of the purlins. The angle of inclination of the valley changes accordingly. The roof truss system with a valley can be made using a spacer or non-spacer method. If spacer rafters are installed, then to relieve excess stress, a horizontal tie should be secured at the bottom of the structure.

Installation of the valley

The design and installation of a roof with valleys is quite complex. In this case, mistakes can lead to roof collapse or leaks. One of the purposes of the valley is to ensure the removal of precipitation. Valleys differ in their design:

To install a valley on mating slopes, it is necessary to install a continuous sheathing. Waterproofing is laid along a wooden gutter - it is better to lay it in two layers. Then the valley is secured with self-tapping screws. If its joints are horizontal, the overlap should be at least 100 mm (recommended value is 300 mm). If the valley is mounted on a slope with a slight angle of inclination, it is recommended to add another layer of waterproofing, and when installing the valley on a metal tile roof, additionally use a self-expanding sealant.

An open-type valley is easier to install and removes precipitation better. Closed and interlocking structures are typically used on steeply pitched roofs covered with certain roofing materials. Their disadvantages include increased costs for additional waterproofing and some installation difficulties. Intertwined and closed valleys drain precipitation worse, and in cold climates winter time serve as a place for accumulation and compaction of snow.

Do-it-yourself roof truss system, device with a valley, video

Construction and design of the roof truss system. The sequence of installation of the rafter system and the features of the roof with a valley along with the video.

Rafter system for a roof with a valley

Make a gable or pitched roof quite simple. Although it will perform its main function, it will not be attractive from an aesthetic point of view. Recently, designs with several slopes and protrusions are gaining great popularity. At the junction of two slopes, a node is formed, which is called a valley. This part of the roof requires special care during design and installation. From the article you will learn the features of a valley and how to make it yourself.

Design and varieties

Only the inner corners of the roof are called the valley. Buildings that form a T or L shape cannot be built without this element. In addition, similar corners are formed in the places where dormer windows emerge, protruding parts of the attic and other architectural delights.

The main task of the valley is to protect the attic space from moisture penetration. The fact is that in this place the roof experiences increased loads due to the fact that a large amount of precipitation accumulates there. In winter, snowdrifts form here and the structure can sag under increased loads.

The internal corner is assembled from two planks, and each is created for its own purpose:

Bottom. In accordance with its name, it is located under the roofing. Attached with self-tapping screws to the cornice board. It performs the main protective functions of containing moisture at the junction of the slopes.
Upper. In the inner corner it is difficult to beautifully design the convergence of the roofing material. Therefore, a second strip is mounted on top, which has only a decorative function.

The valley material usually matches the main covering on the roof. In some situations, it can be replaced with a sheet of galvanized steel. It is important to choose metal with a protective coating, since it will often have to come into contact with aggressive environments.

When constructing a valley, it is important to follow all the rules for the construction and installation of rafters. If one of them is neglected, then there is a threat of frame collapse. However, the standards differ for various types designs. Depending on the roofing material used, one of two types of frames is used:

Articulated and closed. Used on slopes with a large slope angle and for roofs made of flexible material, for example, soft tiles. This type requires the installation of additional layers of waterproofing.
Open. Here the slopes connect to each other at a flatter angle. The joint is closed with a special gutter through which precipitation flows. This design does not require special expenses for the installation of excess waterproofing.

Features of the rafter system and sheathing

Depending on the slope of the slopes, wooden rafter legs are attached to the valley at a certain angle. However, for each side this indicator may differ from the other. Where the beams meet, a thicker rafter is installed. The method of fastening to this place depends on the length of the rafters. If it is less than two meters, then nails are enough, otherwise metal pads will be needed for reinforcement. Before installing the valley, the place of the greatest load is calculated, and a supporting jib is installed there.

Where the slopes meet, it is necessary to strengthen the roof sheathing. How much amplification will need to be done depends on the type roofing covering:

Metal tiles. In order for the corner to withstand the load, additional ones are fixed between the planks of the main sheathing. Thus, in a critical place the step is halved. It is important that the length of the sheathing be greater than the width of the valley plates.
Profiled sheet, ceramic tiles and slate. For these materials, boards with a width of more than 100 mm are mounted along the mating axis. The number of boards depends on the width of the substrate; two or three pieces may be needed on each side.
Ondulin. The valleys are set back 75 cm from the central axis and fixed one board at a time less than 100 mm wide. A special groove should be placed in the resulting space.
Soft roof. For this material, the lathing is made solid and there is no need to reinforce it in any way.

Frame structure

The main part of the roof valley is attached to a slanted rafter, which on one side rests on the ridge and on the other on the mauerlat. In some cases, for example, when installing a skylight, the mounting locations may change. Depending on the type of roof, the height and shape of the ridge varies. This applies to both the main and secondary structures.

To change the geometric shape of the roof structure, it is enough to lengthen or shorten the run. Along with these manipulations, the slope of the valley will change.

The valley rafter system is assembled as follows:

Attach the purlin from the secondary one to the rafter post of the main roof structure. Pins are used for connection.
The rafters are fastened using nails driven in at an angle. This connection meets all safety requirements and can withstand sufficient load.
Install an inclined rafter from the place where the purlin is attached to the mauerlat.
Sprigs are attached to the inclined rafters. For connection, support bars are fixed in advance at the points of contact.

The abutting flanges transfer high compressive stress to the diagonal rafters. Because of this, the beam heavily loads the joint of the mauerlats. To reduce the pressure from the inclined stoprail to the post to which the secondary roof purlin is attached, stretch the connecting tie. It works in tension and does not allow the valley stop to squeeze out the mauerlat. If the roof is hip, then the tie is connected between two diagonal rafters.

In addition, if under some circumstances the main ridge loses its fulcrum, the tightening will act as a thrust. So, it can prevent emergency roof destruction.

The tightening or grip must be placed at the base of the valley, since in a high position it will stop working in tension. In this position, the beams work in compression and are called crossbars.

As you can see, the rafter system for the valley is not particularly complicated and you can install it yourself. At the same time, it is important not to make a mistake in choosing the cross-section of the beam and the reliability of fastening. Then you will collect unique roof and it will last for several decades without leaking.

Roof with valley and rafter system: how to install

Design and types of rafter system for a roof with a valley. Features of laying the sheathing and a description of the frame structure.

Valley plank - what is it and how to install a valley plank + sheathing and rafter diagram

A properly equipped roof of a house is an important component, providing protection to the building from winds, precipitation or sunlight.

The main load falls on the roof, as on the outer plane, which has direct contact with all weather or climatic manifestations.

Any defects in the design of the roof mean the possibility of water getting inside, the formation of centers of destruction of the rafter system or the danger of demolition of the roof due to gusts of wind.

That's why correct use all elements of the roofing covering, which form a sealed layer that reliably separates the interior space from contact with the atmosphere, is an important and responsible part of the design of the roof.

Roof coverings are divided into two groups:

The actual coating, i.e. leafy or roll materials, in the set creating the plane of the slopes.
Extensions - all design elements of junctions, transitions, gutters, etc.

At the same time, it is the additional elements that require the most careful, responsible approach to installation, since they often take on most of the load for draining or removing rain or melt water and snow. One of these elements is the valley.

What is a valley

A roof valley (sometimes a valley) is a term that has two meanings. First of all, This is the area of the roof where two planes meet, forming a depression. This - general concept, defining the meaning of the term, its meaning. In construction practice, another, narrower meaning of the term is used: this is what they call type of additional elements made to design the joint of planes. The presence of two interpretations sometimes causes some confusion caused by confusion of the two concepts due to lack of awareness.

Endovy (in in a general sense) are of three types:

Open.The place where the planes meet does not have a tight seam and is covered on top with an additional strip.
Closed. The joint is tight and straight.
Intertwined. A tight joint with transitions of elements of the roofing material pattern onto each other in an alternating order.

The second and third types are much less common, since their construction requires workers with experience and special knowledge. With a large selection of roofing materials available for sale and different properties and installation specifics, it is difficult to find people who know how to design complex roofing elements, not easy. In addition, all work is carried out in difficult conditions, at heights, which creates additional difficulties.

It should be taken into account that in any case it is not possible to achieve complete tightness of the connection, and the meaning of all efforts, in fact, comes down to achieving a purely decorative effect, which often means a waste of time and labor.

Valleys as an additional element are also divided according to the method of installation:

Bottom end. The internal valley is installed before laying the roof, since it is located under the general layer. In any case, with any type of valley design, the bottom strip is present as a mandatory element, since it is it that serves as a gutter that drains water into the drain. Without it, the junction of the planes will be a continuous gap.
Endova upper. This element is installed on top of the roofing material and serves, firstly, to create visual completeness, neatness of the connection, and secondly, it prevents the accumulation of various debris in the recess of the roof. Any foreign objects, pine needles or fallen leaves, small debris, etc. will gradually create a barrier to the free flow of water, so it will find a way out in another place, which will definitely create a problem. The presence of a top bar prevents such accumulations.

Both types of valley strips have their own installation features. Each type of roofing material has its own set of additional elements, fully consistent with each other both in constructive and design terms, so before installation you should familiarize yourself with the rules and features of working with this material.

What is a roof valley: photo

What are valleys made of and what roofing materials are they used for?

For the manufacture of valleys, the same material is used as for the main one. coatings - asbestos cement is used for slate, galvanized steel sheet is used for metal tiles or corrugated sheets, etc.

If a protective coating is used to protect the material from corrosion, as is done in the production of metal sheet materials, then valleys are similarly provided with a layer of protection.

That is, complete compliance of elements is achieved, which when assembled look like parts of a single whole. However, in some cases they resort to using additions of one type to decorate the material of another.

Most often, this combination occurs during the construction slate roofs, since asbestos-cement elements are not as common as other components. Getting out of the situation in this way, of course, somewhat affects the aesthetic perception of the roof, but in functionally everything works correctly.

Anyway, Fully matching components are created for all sheet roofing materials, allowing you to design all areas of the roof, and valleys in this sense are no exception. It makes no sense to use them for working with soft roll coverings, since their installation technology involves completely different actions, and sealing corners does not require additional structures.

Diagram of the rafter system at the site where the valley is installed

The rafter system at the transition points of one plane to another must provide straight and even lines without depressions or distortions that could cause incorrect installation valleys.

The device for connecting two valleys on a slope can be of the following types:

Butt-butt. With this method, rafters of different slopes are connected with their ends at an angle. Careful calculation and accuracy in work are required to avoid bending or distortion.
overlap. The rafters do not connect to each other, being placed “at random”. This option provides a greater guarantee of maintaining the clarity of the transition of planes and maintaining straight lines.

Rafter system for the valley

For correct and precise installation of rafters First of all, you need to designate the runs - the lines connecting the planes. This is done using a stretched rope between two extreme points run and are guided during assembly along this line. With due care and attention, the design turns out smooth and suitable for performing its functions.

An important element of the valley rafter system is the sheathing. At the junctions it is made continuous, with mandatory waterproofing. Installation of the bottom strip should be done on a flat, straight area so that the pressed strip does not receive any deformation.

Any bending will cause the protective coating to peel off., which will automatically start corrosion processes and cause rapid failure of the bar. If we take into account the presence of a layer of insulation and waterproofing, lining the inner surface of the attic, etc. finishing coatings, detection of damage to the plank will not occur immediately.

By that time, significant damage will have been caused due to water penetration into the roofing materials and elements of the rafter system. Replacing the strip will also require serious work, as well as a lot of time.

Installation of the valley

How to install the additional element correctly:

First of all it is necessary make sure that the substrate is constructed correctly and accurately, that there are no distortions, and that the structure is strong. Loads on valleys can be significantly higher than on flat areas of slopes, since it is in the gutters that snow accumulates, creating strong pressure on the system.
Wooden elements rafters and battens are treated with an antiseptic and the area is waterproofed. It is an additional operation for the valley, general waterproofing of under-roofing materials - another position.
The bottom strip is being installed. The procedure is carried out from the bottom up, the individual parts are overlapped with an overlap of 10-20 cm. All joints are treated with sealant.
The roof is being laid. The joints between the material and the bottom strip are additionally sealed.
The top bar is installed.

How to make a roof valley

All connections are made using roofing screws equipped with a gasket made of special wear-resistant rubber. All areas of possible leaks are treated with sealant.

Other types of additional elements

In addition to valleys, other roofing elements are also manufactured. Any area that requires additional design has a corresponding additional element.

Exist the following types of additional elements:

So, we have fully answered the popular question - what is a valley and how to install additional material correctly. All elements have clearly defined functions; their use is an important and irreplaceable stage in the construction of a roof. Most often, attempts to somehow replace ready-made additional elements with handicraft or non-standard parts lead to design inconsistencies and failure to fulfill their purpose. Saving in this case leads to large losses later.

Constructive and functional features valleys - ensuring effective drainage and an aesthetically pleasing appearance of the valley roof.

The elements available on the market allow us to fully solve both issues, provided that they are installed correctly and carefully. It is quite possible to carry out the work yourself, the main thing is to familiarize yourself with the procedure and the specifics of the material and do not forget about safety measures when working at height.

Valley - what is it (photo), installation of the connection of two valleys on the slope (upper and lower), installation of sheathing and rafters

In this article you will learn what a valley is, as well as the types of valley: upper and lower, internal and external. Diagram of the arrangement of valley strips on the roof, consider the connection of two valleys on the slope, the design of the sheathing and rafters. Let's talk about how to properly install a valley roof + photo.

Not only its durability, but also its architectural attractiveness depends on how the building is covered. For this reason, the utmost attention is paid to the construction of the roof. On the other hand, the complex geometry of this structural element should not affect the reliability and tightness of the corners and joints of individual slopes. When choosing an intricate roof with a complicated configuration, it is important to ensure the correct installation of additional elements - valleys or valleys. This determines how effectively the roof will cope with the removal of melt and rain water.

Valley roofing - what is it?

A valley is a structure that is installed at the junction of two adjacent slopes that form an internal corner. In another way, this roofing element is also called a gutter, since, in fact, it is a real gutter necessary for removing precipitation. The need to install this element is determined by the following factors:
the connection of adjacent inclined surfaces requires special tightness to prevent melt and rain water from getting under the roof; water from the slopes of complex roofs flows and accumulates in the inner corners, so it is necessary its movement into the drain and further into the drainage system;
The junction points of the slopes are areas where large amounts of snow accumulate in winter. With the help of valleys, it is possible to strengthen the rafter system and evenly distribute the additional load on the wooden structure.

The dimensions of the valley depend on how long the junction of adjacent roof surfaces will be. In addition, the width of the valley depends on the amount of precipitation and the angle of inclination of the slopes - the lower the slope, the wider the protective structure should be. Typically, joining internal corners requires cross-shaped, as well as L- and T-shaped roofs, of which the latter are the most popular.

Arrangement of the valley allows you to protect the joints of adjacent slopes from moisture penetration and make the roof more attractive

In some cases, the installation of valleys is also required on bends that are formed when installing attics or dormer windows. The grooves of complex, or, as they are also called, multi-gable roofs are the most vulnerable places, therefore, during installation they require extreme care and unconditional adherence to the technology of their arrangement. We should not forget that a more complex roofing structure increases the cost of construction and makes operation more expensive, intricate and original roof further.

Classification and arrangement of roof gutters

The installation of valleys is carried out before laying roofing materials on the roof slopes. Depending on the complexity of the design and the method of arrangement, grooves are divided into two types:

lower;
upper ones

The task of the lower elements is to protect the junction points of the slopes from moisture entering the under-roof area. They have folds along the edges, making them high level Wastewater prevents them from overflowing into the attic space. In addition, additional sealing of the roof is provided by roll waterproofing, which is laid on the sheathing with a sufficient margin of width. The bottom strips are made of galvanized or stainless steel sheets, aluminum strips, etc.

On the bottom panel of the valley, flanges are made to protect the under-roof space from leaks

The upper valley, which protrudes 15–20 cm above the main valley, serves for decorative purposes, hiding an unsightly gap at the junction of two slopes.

The top panel of the closed valley protects the valley from debris and gives the roof structure a finished look.

Most often, the facing strip is made from the roofing material of the same name and is installed in place after the roof is completely covered.

In order to prevent the valley from sagging, a continuous sheathing is installed under it, which is attached directly to the rafters or counter batten slats.

According to the installation method, the connecting elements are:

open;
closed;
articulated (intertwined).

Valleys of the first type are equipped using only one lower protective panel, so outwardly they look like an uncovered zone of articulation of adjacent slopes. Being the most simple option, an open joint can be used on roofs with a slight slope. The advantages of such a solution are the efficiency of drainage, speed and ease of installation. The disadvantages include the external unpresentability of the design.

Closed gutters are constructed using bottom and top panels. This type of joining requires the tightest possible fit of inclined surfaces and can provide protection against leaks on roofs with steep slopes.

An articulated valley is a method of joining slopes in which roofing sheets are intertwined with each other, making it possible to more reliably protect the interior from moisture.

Depending on the method of installation, valleys are divided into open, closed and intertwined

The advantages of closed and articulated valleys are the most effective moisture protection and visual appeal - a roof with such valleys looks monolithic and complete. The disadvantages include more complex installation and, as a result, increased cost of the structure.

When determining which valley to install on a particular roof, they first of all focus on the type of roofing material and the angle of inclination of the slopes, and only then pay attention to the aesthetics of the structure.

Features of arranging negative roof fractures

The joints of individual slopes of multi-gable roofs are very vulnerable to the penetration of rain or melt water, since it is very difficult to connect drainage panels without a gap. In addition, they experience high loads from the snow mass in winter period. Therefore, when installing grooves, you must follow certain rules:

When installed correctly, the roof covering at its attachment points should touch the sheathing boards on which the gutters are installed.

How to install the valley

Installation of gutters is carried out in several stages. First, the rafter base is assembled at negative fractures and waterproofed. After this, the lower strip is installed, the seals are mounted and, if necessary, the structure is covered with upper (decorative) elements.

Materials and tools

To install a valley on a multi-gable roof you will need:

sheathing boards;
sheet metal (galvanized, stainless steel or aluminum);
panels from the selected material (metal tiles, ondulin, flexible roofing, etc.);
roll waterproofing;
sealant;
porous sealant;
nails;
self-tapping screws

When installing a gutter, a standard set of tools for working with metal products is required.

To quickly and efficiently carry out installation, you should prepare the following tools in advance:

hammer;
screwdriver;
rubber or wooden mallet;
metal scissors;
brush with stiff bristles;
carpenter's pencil or marker;
bubble or laser level;
roulette;
round nose pliers.

In addition, you will need a long and even wooden slats. It is needed to form hems on the bottom bar.

Installation of rafters

The wooden frame for installing valleys in most cases consists of slanted rafters. When developing a rafter system, it is taken into account that the ridge components will be located at the same level, therefore, in the lower part, the supporting elements of the roof rest on the Mauerlat, and the other end is installed in the ridge purlins.

To join the slopes of the secondary roof, an additional purlin is used, which is supported on the break

If you plan to install a gable, hip or hip roof, then you will have to put up with the fact that the ridge in different parts will be located at different heights and have a complex geometry. To adjust the first parameter, it is enough to change the slope of the grooves, while the geometric shape of negative breaks can be corrected by lengthening or shortening the length of the purlins.

When constructing a rafter system, the following rules are followed:

To remove excess load on the frame, the mowing beams and racks are connected with ties. As for L-shaped roofs, in this case the rafter that forms the negative bend is connected to the opposite hip.

Installation of drainage gutters on negative bends of complex roofs

Despite the fact that the design of valleys is not particularly complex, the order of their installation on roofs made of various materials, there are differences.

Gutter on slate and tile roofs

The traditional method of installing a valley for roofs made of tiles, slate or roofing sheeting consists of the following steps:

At the work site, a reliable ladder is installed and the roof is cleared of debris.
Starting from the roof ridge, remove part of the roofing material. Remove from both sides of the negative fracture tiled covering to a width of 20 to 30 cm, and in the case of a coating made of sheet material dismantle individual floor panels. If additional elements of water drainage systems from adjacent surfaces are installed on the roof, then the roof is removed to a width that will ensure ease of carpentry work.
To avoid damaging the roofing sheet nailed, place it under the tool. wooden beam OK 30–40 mm thick
Additional elements of the rafter system are installed and a wooden flooring is arranged, which will serve as a support for the valley. The width of the gutter bed must be at least 30 cm in each direction from the axis of the negative angle. As for thickness, the flooring is made from the same boards as the sheathing. If it is necessary to connect lumber, joining is performed on the rafters.
To prevent the bottom panel from sagging, a solid wooden base is installed underneath it.
A strip of the required width is cut from a sheet of roofing iron - it will become the base of the future groove.
The side edges of the bottom panel are bent at an angle of 90 degrees and profiled using a wooden block.
A longitudinal axis is found on the metal strip and bent in such a way as to obtain a gutter with an internal angle, which will be 5-10 degrees larger than the valley break. Using the described method, prepare the required number of bottom panels.
Installation of the drainage structure begins from the eaves side. One of the manufactured elements is laid on the sheathing and cut to size, having previously retreated 30–40 mm, which will be needed for installing gutters.
Installation of gutters begins from the eaves side, leaving space for installing gutters
When installing the gutter, an overhang of 80–100 mm wide is left. In this case, the protruding part of the flange is folded inward.
Using construction staples or nails Ø2–3 mm, the bottom panel is secured to a wooden base. The distance from the edge should be 20–30 mm. At this stage, capital fixation is not required. The final fastening is carried out simultaneously with the installation of the removed roofing material.
The installation of the next valley element is carried out in a similar way, ensuring an overlap of at least 100 mm, and in the case of starting bottom panels - at least 200 mm. The joints are protected from moisture penetration using sealant. To prevent debris from getting under the roof, a special protective strip is glued to the edge of the metal elements.
When arranging a long valley, several panels are used, the joints of which are treated with sealant

After installing the open valley gutter, the drainage structure is waterproofed. For complete protection against leaks on roofs with gentle slopes, moisture protection of the open valley is ensured by two or three layers of insulating material.

Video: valley for natural tiles ONDO

Features of arranging valleys on a soft roof

Installation of drainage gutters on roofs covered with soft roofing materials is possible in two ways:

open;
by cutting method.

The first option involves laying the valley carpet on the lining waterproofing along the entire length of the negative fracture with a horizontal offset of 2–3 cm. In this case, the back of the material along the entire perimeter is treated with moisture-proof mastic. The width of the waterproofing layer must be at least 10 cm.

The reverse part of the waterproofing material is generously coated with bitumen mastic

Fixation is carried out with galvanized nails in increments of 20 to 25 cm at a distance of at least 2–3 cm from the edge. If continuous laying is not possible, then the canvases are mounted with an overlap of at least 30 cm and carefully treated with a waterproofing compound over the entire mating surface.

When arranging a drainage zone by cutting the roofing material, there is no need to install a valley carpet.

Arrangement of negative roof angles using the “undercutting” method is carried out in accordance with the following rules:

Rows of tiles should be laid from the side of a gentle slope, with a width of up to 300 mm extending onto a steeper surface.
As is the case with open method, each stripe should be additionally fixed at the vertex.
After laying the slope with a smaller angle of inclination, a chalk line for cutting the tiles is beaten on the adjacent roof. This line should be no closer than 7–8 cm from the center line of the valley.
Before final fixing of the tiles, the protective coating of the adhesive base on its reverse side should be removed, and if it is missing, a sealing mastic should be applied.

If the valley is installed using the articulation method, then the installation is carried out in full accordance with the method described above. The only difference is that individual strips of ordinary tiles are intertwined when laid on an adjacent roof.

Video: how to arrange a valley under a soft roof

Gutter on a metal roof

As in all other cases, on a metal tile roof under the valley it is necessary to make a continuous sheathing. Additional flooring provides the necessary rigidity and prevents sagging of the structure. Most often, a closed gutter is installed on such roofs, along the bottom of which water flows into the drain. The top strip of the drainage system covers the edges of the metal panels, protecting them from corrosion and increasing the aesthetic value of the valley.

On a metal tile roof, a closed valley is most often installed, consisting of lower and upper planks

Installation of a valley on a negative fracture of a metal tile roof is carried out in the following order:

Due to the fact that moisture can penetrate into the mounting holes, experts recommend using screws and nails when attaching the lower gutters. The panels can be fastened using homemade clamps - strips of metal, which are attached on one side to the upper edge of the groove, and on the other to the sheathing.

The formation of an ice crust on the roof surface in winter can prevent meltwater from draining during a thaw. At the same time, the water level in places of negative breaks can rise above the line of the valley panel flanging, creating a risk of flooding of the attic space. To prevent such cases, gutters, like other potentially dangerous places in the drainage system, must be heated.

For these purposes, the joints of mating slopes are equipped with heating cables.

A self-regulating heating cable is used to heat the valleys and surfaces of adjacent roof slopes.

The heating elements are laid in the lower part of the valley, covering from 1/3 to 2/3 of the length of the valley. The power of the cables is determined based on the area of the heated surface and a minimum value of 250–300 W/m. In this case, the installation itself is carried out in several parallel lines, the width of which depends on the thermal performance of self-regulating heaters and the predicted amount of precipitation in winter. In any case, the cable laying step should not exceed the thickness of the snow cover. In practice, the distance between adjacent elements varies widely and can range from 10 to 40 cm.

To attach cable heaters, use perforated mounting tape, which is fixed using self-tapping screws or rivets. The attachment points should be located as far as possible from the center line and must be treated with polyurethane or rubber sealant (silicone compounds are not recommended).

When choosing a method for fixing cables, it is necessary to take into account the galvanic compatibility of all connection elements, otherwise they will be subject to severe corrosion and destruction.

On soft coverings, the mounting tape is fixed with pieces of the main roofing material, which is welded using a gas torch. Otherwise, when installing heated gutters, they are guided by the same rules as for cornices, trays and horizontal drains (gutters).

Gutter repair

If moisture penetrates into the negative corners of the roof from the attic, this indicates that the gutter was installed in violation of the technology or requires repair. Restoration work involves several stages:

Dismantling the roof covering that is adjacent to the junction of the slopes. As a rule, there are no problems in this regard on tile, slate and other roofs with a rigid roof. As for soft tiles, prolonged contact and interlayer diffusion can make them difficult to remove. To facilitate the dismantling process, this coating is carefully heated gas burner or a blowtorch.
Removing the bottom valley panel.
Replacement of damaged wooden flooring elements (if necessary) and restoration of waterproofing.
Repair or replacement of individual gutter panels and their installation in place in compliance with all requirements for moisture protection of joints and mounting holes.

After completion of the restoration work, the removed roof covering is returned to its place. If necessary, cracked tiles or slates are replaced, and damaged areas soft roof repaired using bitumen mastic and patches made of the same material.

Valleys are an obligatory element of multi-gable, hip, hipped and other complex or combined roofs. The absence of leaks into the under-roof space depends on how carefully and efficiently the places of their negative breaks are arranged. Extreme care when installing gutters will help make the roof reliable and durable, thanks to which you will forever forget about worries during heavy rains and spring snowmelt.

The higher the complexity of the roof design, the more different elements it includes. Classical gable roof consists of only two slopes, at the junction of which an outer edge is formed - the ridge. Multi-pincer variants, which have more than one ridge, form, in addition to external ones, also internal angles between planes, which are called valleys. Many inexperienced builders wonder what a roof valley is and how to make it correctly. This article will tell you about the design and installation features of this structural element, which affect the operation of the entire structure.

A valley is a functional element of a roof, which is formed at the junction of two roof slopes of a complex, multi-gable structure.

Simply put, this term refers to the internal angle between two adjacent slopes. Due to the presence of this structural part, valley roofing is characterized by increased complexity of design, installation and operation. The functions of the valley are:
Connection of slopes. Two inclined planes of roof slopes are connected, forming an internal angle at the junction, called the valley.
Collection and transportation of water. Valleys are internal corners, so water flows into them from the slopes, collects in a large stream and is transported to the drainage system.

Snow accumulation. Also, the places where the slopes meet are places where snow masses accumulate, so the load on the rafter system in these areas increases.

Please note that the installation of a valley roof must be carried out in accordance with load calculations and the working design, since this structural element is subject to increased loads due to the accumulation of snow and atmospheric moisture.

A multi-gable roof is a complex structure that consists of several slopes, has more than one ridge, and also valleys. The groove between the inclined surfaces, formed at the point of their abutment, is a vulnerable point through which leaks often occur if the installation is performed incorrectly.

In accordance with the characteristics of the device, the following types of valleys are distinguished:
Open. It is an open joint between two slopes, into which a special gutter is placed. This is the easiest to install version of the gutter device, used on roofs with a slight angle of inclination.
Closed. This version of the valley is different in that. That in it the slopes fit tightly to each other without forming a gap. A closed valley is suitable for roof structures with steep slopes.

Intertwined. An intertwined valley is a method of constructing a joint between two mating slopes, in which sheets of roofing material are intertwined, reliably protecting the inner corner from moisture penetration.

As a rule, the valley of a roof made of metal tiles or corrugated sheets consists of several elements: reinforced waterproofing, an internal strip that protects the joint from the flow of atmospheric moisture and a decorative detail that makes the appearance of the valley more attractive.

Device Rules The junction of the roof slopes of a multi-gable roof is characterized by increased vulnerability to the penetration of melted or rain moisture, since it can be connected without a gap waterproofing material

It's hard enough. In addition, the valley is subjected to increased loads that occur when snow mass accumulates in winter. Therefore, the valley roof must be designed in accordance with the following requirements: At the junction of the individual parts of the multi-gable structure, the sheathing must be reinforced. Solid flooring made of edged boards
helps to more evenly distribute the weight of the roofing material and the load placed on the roof when snow falls. The valley of a multi-gable roof requires enhanced waterproofing. To protect the valley from water seepage during rainstorms or melting snow caps, it is necessary to provide it with additional waterproofing; for this purpose, a special moisture-resistant.

Before making a roof valley, you need to carefully consider its design so that during operation it does not cause leaks. When creating a project, it is important to correctly calculate the load to which it will be subjected. For example, ceramic tiles weigh much more than corrugated sheets, so they require additional reinforcement of the sheathing.

Requirements for materials and components

A valley is also called a special strip for equipping internal corners between roof slopes. For each roofing material, special components are manufactured to protect the gutter from moisture penetration.

Valleys for corrugated sheeting, roofing steel and metal tiles are corners, and additional elements for tiles resemble semicircular gutters. The main thing is that the material from which they are made meets the following requirements:
Additional elements must be selected in accordance with the roofing material with which the roof is covered.
The material from which the additional elements are made must be highly resistant to moisture in order to protect the gap between the roofing material from moisture penetration.

The additional elements used for the gutter equipment must have high mechanical strength and a long service life.

It is interesting that previously manufacturers did not produce special additional elements for gutter equipment, so developers used various improvised means and remnants of roofing material for these purposes. Nowadays, reliable and aesthetically pleasing valleys are produced, suitable for any color and type of coating.

Installation technology

Many inexperienced roofers do not know how to properly make a valley in order to avoid leaks during the operation of the roof. In fact, this is a fairly simple technological process that is performed during the roofing process. Installation of the valley is carried out using a screwdriver, self-tapping screws, metal scissors, waterproofing film, sealant and a special strip.
Installation is carried out as follows:
Then, on top of the waterproofing, using a screwdriver and galvanized screws, the internal valley strip is attached to the sheathing.
After laying the roofing material, the gap where the slopes join is generously coated with sealant, and then closed with a decorative corner, fixed with roofing screws with special press washers.

Please note that only a valley roof, installed according to technology, reliably protects against precipitation and also does not deform when the load increases.

Video instruction

Valley roofs

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

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

Metal roof valley

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.

The sheets are attached to the sheathing in the regular places - in the lower part of the oxen 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 not everyone is happy with the appearance of the cut sheets. In order to close them there is a 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

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

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

Roof tiles

Ondulin

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.

Endova- this is the junction of the planes of two roof slopes with the resulting internal angle (gutter or groove).

Applicable names: valley, valley, valley, valley.

The valley is considered a complex and most vulnerable element of the roof structure, which is subject to high external and structural loads during the operation of the roof. Valleys are the most vulnerable place for leaks when snow and ice accumulate on the roof. Particular attention is paid to waterproofing all joints and seams in the valleys.

Endova what is this?

Endova on the roof- This is a gutter formed at the intersection of the roof of two roof slopes, forming an internal corner. The complete set of any roofing includes special components that are personally responsible for the valley (valley carpets, valleys, valley strips, etc.) For each type of roof, the valleys and their arrangement must be considered separately, since this is particularly important element on any roof. More details in the links at the bottom of the material.

This is a wooden beam embedded in the structure of the rafter system at the intersection of adjacent roof slopes at an internal angle. As a rule, on large valleys, reinforced timber is used (larger cross-section than for rafter legs). The best solution for valleys in the rafter part are two rafters “knocked down” together. This design solution makes it possible to more successfully deal with deflection and external loads. As you know, two bars are much stronger than one bar of similar sizes and respond much more effectively to deflection due to the different structure of the tree. So, for example, two “knocked down” beams measuring 40×200 mm are stronger than one solid beam measuring 100×200 mm.

Caring for a roof with valleys

The presence of valleys on the roof leads to the need to monitor the condition of the roof: periodically inspect and clear any debris that may have accumulated in them.

A special case needs to be considered valleys covered with cashers(metal tiles) and proximity to the roof of trees. Fallen leaves, needles and cones often clog valleys, creating stagnation for dampness and water, thereby causing rotting of metal valley elements.