Gutters for flat roofs. Why do you need a roof drain, types, rules for installing a drainage system Drain drain for a flat roof

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Modern drainage consists of gutters and risers combined into one structure. It is necessary for buildings, because otherwise the walls and foundation will quickly become unusable. Drainage systems can be unorganized and organized, internal and external.

Unorganized drains can usually be found on buildings of low height, when the roof slopes are located at a sufficient distance from the outer walls. There are often no organized water drains near houses with pitched roof. But such cases are the exception rather than the rule, since most buildings have drainage systems.

Materials for manufacturing elements for drainage

The domestic building materials market offers customers a huge range of elements that are necessary for arranging a drainage structure for a roof. Gutters, drainage funnels for flat roof, the pipes have different shapes and they are made from various materials.

The most popular drainage systems are those made from galvanized steel. They are usually installed on multi-storey residential buildings (see photo). The main reason for the popularity of such gutters is their low cost. Therefore, owners of private households often prefer them to drain water from the roof. IN last years can be found more and more often.

Copper gutter components are also available, but they are expensive and therefore rarely installed. In addition, they do not always harmonize with the appearance of the house and roof. A copper roof is suitable for such products, but they are not compatible with tiles. Often, property owners prefer to buy gutters and other elements painted in specific color or having a polymer coating.

Products made of copper are considered the most durable and reliable. When choosing cheaper options, you should consider what type drainage system to be installed and depending on the material from which the roofing is made. So plastic and metal elements can be used for arrangement internal drainage, but for external systems it is advisable to use metal drains - steel ones are less dependent on the influence low temperatures. PVC elements are ideal for flexible tiles, and slate, known to many domestic consumers, is best combined with metal products.

Device and application

An internal drainage system is installed when the roof structure does not allow creating external structure, for example, if the building has a flat roof.

To drain water, there are slopes in the direction of the places where drainage funnels for flat roofs, which are produced in different diameters, are mounted.

If the difference in heights of two adjacent roofs exceeds a distance of 4 meters, then experts recommend creating a separate system for each area.

The main elements of internal drains are:

• water intake funnels;
• pipelines;
• collectors;
• connectors, etc.

According to SNiP standards, water flow must be drained into a storm drain. In the case where it is absent, the owners use trays to receive water that enters them through drainpipes. When these elements are absent, the water flow, flowing down the blind area, ends up on open ground.

Drainage funnels

Two types of funnels are sold on the domestic building materials market:

• bell-type (they are installed on sloping roofs);
• flat (such a drainage funnel for a flat roof is used for arranging a drainage system on horizontal tile or asphalt roofs).

Most often, professionals install a bell-shaped cast iron roof drainage funnel, since it does an excellent job not only with its functional purpose, but also plays the role of a reliable filter, thereby preventing all kinds of debris, such as tree branches and leaves, from entering the drainage system.

This funnel consists of three parts:

• cast iron body, it is mounted directly into the ceiling:
• receiving grille, which is made of the same material as the housing. It is cylindrical in shape and has holes and ribs;
• removable cast iron lids with holes.

It is imperative that the drainage funnels for internal drains and the ceiling must have a sealed connection with each other, otherwise moisture will get under the roof, which will lead to the formation of fungus or mold that is harmful to human health. When installing drainage pipes and risers, as a rule, cast iron, tin and polyethylene products are used. Often, asbestos cement elements are used to create an internal system.

Concrete, reinforced concrete, ceramics, and asbestos cement are suitable for the manufacture of longitudinal sections of drainage systems. In individual households, products made of cast iron, galvanized sheet or PVC are used.

Features of installing water inlet funnels

When installing internal drainage systems, a number of rules must be followed when installing funnels:

1. Internal drainage funnels should be placed evenly throughout the roof.
2. The shortest distance from the wall to the funnel should be at least 1 meter;
3. Between funnels that are connected to one branch of the water pipeline, the gap cannot be more than 20 meters.
4. Places for installing funnels should be located slightly lower than the rest of the roof surface.
5. The roof drainage funnel and the pipe are connected at right angles.

Types of internal drainage systems

Depending on the design solution, the following types of internal drainage systems are distinguished: gravity and siphon.

Gravity drainage is used to collect precipitation and freely drain it along inclined gutters - in in this case water partially fills the system.

The functioning of siphon drainage is based on the principle in which the drain is completely filled with sediment and thereby a water column is formed, starting from the funnel and ending at the point where the water flow is discharged into the sewer. When the level of precipitation in the vertical part of the system drops, due to the creation of a vacuum, water is sucked from the funnel into a vertical riser. Thus, it is removed from the roof surface not freely, but forcibly. This method is more effective, but for constant maintenance siphon effect requires complete tightness of the system, which is achieved by selecting exact size pipes and uses modern materials providing high-quality sealing.

In such systems, there is such a funnel assembly for the internal drain as a flow stabilizer, due to which water flows into the side openings and thereby prevents the penetration of air. Installation of the siphon system is carried out using butt welding. In addition, it does not have temperature compensators, and this circumstance also makes the system airtight (read also: " ").

The advantage of the siphon system is that:

• with insignificant volumes of precipitation it functions as a gravity structure, and with large quantities rain or melt water is easily handled by the water flow. When installing it, fewer funnels and risers located vertically are required;
• it is possible to reduce the diameter drainage pipes, which has a positive effect on the amount of costs;
• lower horizontal pipes are installed without slope;
• Self-cleaning of the system occurs as a result of the rapid movement of sediments.

Wastewater disposal in the system

After transporting precipitation and melt water from the roof, regardless of the type of internal drainage system and materials for its manufacture, it is necessary to provide a place where they will be collected (read: ""). Experts do not recommend connecting the drainage structure to the general sewer system in the building, since it can quickly fail as a result of clogging. To do this, they create a special system called “storm drainage” (read: “”).

Typically, runoff from the roof is diverted to the nearest ravine or directly to open area– this method of drainage is called surface. It consists of a network of drainage channels and sand catchers.

The above methods for draining drains refer to organized systems, but in reality, owners of private houses simply take the pipes outside and the collected sediment flows down the blind areas to land plot, located next to the property. Sometimes, to collect sediment, they dig a hole and fill it with crushed stone (read: "").

Good example The installation of a roof funnel for an internal drain is shown in the video:

Excess rain, melt water on the roof surface, or its accumulation due to improperly equipped drainage, negatively affects the stability of any building, as well as its operational period. If from slopes roofing structures With a certain slope, water drains naturally, then flat roofs require proper arrangement of a drainage system. A similar question provides an opportunity to solve drainage funnels for flat roofs. In this case, it is important to choose the right products and determine their sufficient quantity.

In this article

Options for drainage funnels

For the production of TechnoNIKOL drainage funnels installed on a flat roof, copper, galvanized steel, and polyvinyl chloride can be used. Copper products are less popular because they are not suitable for all types roofing covering and are quite expensive. The most commonly used are inexpensive galvanized steel funnels. Polyvinyl chloride specimens are perfect for soft tile coverings, ondulin, shinglas.

The following designs of roof drains are distinguished:

• Flat. The drainage system element is mounted at the level of the roofing surface and is used for existing roofs where asphalt or tile material is used as a covering.
• Bell-shaped. These products received this name because of the special protective mesh used for them (leaf catcher), made in the form of a cap and rising above the roofing surface. In addition to performing its main task, this version of the drainage funnel additionally protects the system from clogging with various debris.
• Heated. The funnel for a flat roof is equipped with a heat cable, thanks to which it is heated in winter, thus preventing the formation of ice, and melt water freely flows down the drainage system.
• With horizontal and vertical outlet.

All of the listed types of TechnoNIKOL drainage funnels can be purchased on the construction market in specialized stores.

Drainage funnel device

The modern construction market presents the most various options drainage fittings that differ in design, material of manufacture, quality, and accordingly price.

A standard drainage system consists of the following components:

• frame made of galvanized steel, plastic or cast iron;
• lattice- a filter element (leaf catcher) that prevents contamination of the system;
• downpipe- connects the fitting and the drainpipe;
• gaskets, O-rings - sealing elements at the junction of the funnel with the roof surface;
• thermal cable- an additional design element that prevents the formation of ice in the system and, accordingly, ensures effective drainage of melt water in the winter season.

Important! The roof drainage system, including drainage funnels, must be periodically cleaned so that an unexpected downpour does not lead to damage to the roof structure.

Tips for installing roof drains on flat roofs

When installing a water intake system on a flat roof, it is recommended to consider the following points:

• It is recommended that the roofing surface be preliminarily divided into equal sections. To effectively drain water from the roof, one drainage funnel for a flat roof is designed for an area whose area should not exceed 200 m2, and the diameter of the drainpipe should not be less than 10 cm.
• When placing the receiving components of the water intake system for the most efficient removal of water, the slope of the roofing surface towards them should be at least 2 percent.
• When fixing water receiving funnel To allow the receiver to move relative to the water intake pipe, it is recommended to provide some free space.
• Regardless of the roof area, there must be at least two receivers or one water intake device and a separate storm drain.
• If waterproofing material laid in two layers, then the water receiver is mounted between them. If one layer of waterproofing is used, then an additional piece of insulation made of a similar material is applied, the area of ​​which must be at least one square.
• For flange connection It is recommended to use heated bitumen;
• For better fixation of water intakes on the roof, you can additionally use specialized mechanical connections.

Excess water on the roof or its improper drainage negatively affects both the overall stability of the entire building and the period of its operation. And if on pitched and hip roofs, due to the slope, water can flow down naturally, then for flat-shaped roofs the issue of proper drainage is more than acute. A drain funnel helps solve the problem, but here it is important to correctly calculate the number of elements and correctly choose the type of this irreplaceable part.

The roof funnel is one of the fundamental elements of the drainage system. It is used to divert the flow Wastewater from the roof - from the funnel, rainwater enters drainpipes, going inside the building or outside, along its walls, after which it goes to the ground, into a sewer system specially equipped for this purpose or other containers for household purposes.

Funnel for draining water from a flat roof

Reliable and trouble-free operation of the drainage system is possible only with absolute tightness. This fully applies to funnels, the quality of the connection of which with the underlying elements largely determines not only the speed of water intake from the roof, but also the overall reliability of the roof covering, as well as the safety of the entire building.

As for the design, a typical roof funnel consists of the following elements:

• cover – covers the upper part of the product;
• grid – protects the drain from foreign objects getting inside and subsequent contamination;
• pressure ring - plays the role of a seal to give the product maximum tightness;
• pipe - depending on the type of drain, it can have a vertical or horizontal shape;
• bowl (water receiver) – receives water and transfers it to the drainage system;
• seals - designed to seal the junction of the pipe and the pipe;
• bolts (flanges) – provide fixation of the product.

Technical characteristics and their features

Funnels for draining water from the roof are characterized by a number of characteristics. Manufacturers offer a wide range of all possible models, so there are no problems with selecting the optimal option for any operating conditions.

Modifications for various technical and operational conditions

Materials for making elements

As for materials, the funnel can be made on the following basis:

• Plastic - the basis of such products is a hardened type of polymer substance that is resistant to various external influences and loads. Plastic drainage funnels are quite easy to install, often even without additional use adhesives, and also have a very affordable price. Their most relevant use is considered to be on roofs that are not used at all or are used extremely rarely.
• Metal is also a fairly common option. Steel funnels have high strength characteristics, which allows them to be easily installed on roofs with high traffic, including those intended for training, active pastime, excursions and other things. As a rule, such products are made of galvanized steel - rigid, durable, reliable and resistant to the destructive effects of corrosion.
• Combined option - in this case we're talking about about the combination of two materials at once that are used to produce funnels. Its main part is made of plastic, the upper grille is made of metal. An option is available with both galvanized steel and cast iron. Such drainage funnels are optimal for roofs with average cross-country ability and effective load, for example, those intended for recreation.

Flat funnel for roofs with laid soil

Classification of products and their distinctive features

Based design features, funnels come in the following varieties:

• Bell-shaped - products of this type have a convex protective mesh, outwardly very similar to a cap or glass. Allows you to effectively handle large water flows and provide good filtration to prevent clogging.
• Flat - they are mounted at the same level with the roof surface without the slightest protrusion. Particularly relevant flat funnels on exploited roofs covered with asphalt or tiles.
• Heated - an electric cable is located inside the funnel, which ensures proper heating of the system in winter and eliminates the formation of ice, which complicates normal drainage.
• One- or two-level - the first are relevant if the top covering of the roof is made of waterproofing material. The latter are suitable for roofs with possible shifts - unventilated or made of wood.
• Drain funnel for flat roofs with and without rebate - a crimping rebate is universal option mounting, suitable for various types grounds. Funnels without it have an apron on a roofing material or film basis, which is selected depending on the type of roof covering.
• With outlet horizontally or vertically – outlet water is coming along drains located perpendicular or parallel to the facade of the building. The vertical system is suitable in combination with a typical flat roof, while the horizontal system is more suitable for roofless roofs. There are also funnels with a swivel joint, which can be connected to the riser at any angle up to 90°.

Model with horizontal drainage

The product may have the most different diameter, the main thing is that it matches the cross-section of the drain. Components with a diameter of 100 mm are most often used - this is quite enough to quickly remove even significant amounts of water from roofs various sizes and purpose.

Design quality requirements

Water intake funnel must comply with a number of aspects and technical characteristics, and its reliable and long-term operation directly depends on the following factors:

• The connection of the elements to each other and the fixation with the roof must be as reliable and airtight as possible. If this requirement is not met, water will leak under the roof, causing not only its destruction, but also damage. interior decoration. To avoid such a problem, you should use an additional layer of waterproofing during installation, gluing it over the side of the internal drain.
• Possibility of removing the top cover. This allows for trouble-free cleaning internal space from accumulated debris and sediment. As for the inner glass, it must be solid and connected to the body without the possibility of its removal.
• The fit of the protective cap must be tight with the possibility of rigid fixation to avoid shifts and displacements.
• A protective filter (safety umbrella) must be located inside to prevent short-term contamination of internal surfaces.

Removable hoods for easier maintenance

Features of installation work

Roof drains are not as easy to install as they might seem. Here it is extremely important to carry out correct and competent calculations, which will allow the formed system to effectively cope with any water flows, regardless of their volume. And during installation, the correct sequence of actions must be observed - disruption of the technological process can have very disastrous consequences.

Calculation and basic installation rules

Before installation, the throughput is calculated, taking into account that a product with a cross-section of 10 cm passes about 12 liters of water per second. With a cross section of 8 cm, the throughput is reduced to approximately 5 l/s. If the diameter is 15 cm, then in 1 s about 35 liters of water can pass through it.

Water inlet on the roof

Conducting installation work you need to remember the following:

1. The installation location of the funnels must be below the main roof level. The slope angle between the base and the mounted product must be at least 2°, increasing to 5° after about 50 cm. This slope is created when laying insulation boards, filling expanded clay concrete or pouring the base concrete screed.
2. Drainage funnels should be located as evenly as possible - optimal distance between elements is about 20-25 m.
3. No matter how small the roof area, there should not be less than two funnels on it - if one of them is clogged, the second will take over the functions of drainage. And even with an excess amount of water, one may simply not cope with its functions fully.
4. The distance from the edge of the roof to the nearest funnel should be 1 m or more. As for the minimum allowable gap between elements, it is 50 cm.

Preparing the site for funnel installation

The sequence of installation work

Installation work is carried out in the following order:

1. The entire surface of the roof is marked out into flat sections, lining them up so that there is a slight slope towards the center of each - this is where the funnel will be located. The easiest way is to carry out this procedure even before the roof is covered - in this case, slight pushing at the installation sites will be enough
2. If the base waterproofing has several layers, the body of the drainage funnel is placed between them, which provides additional protection against leakage and protects the structure from possible destruction.
3. The funnel with pipes is connected using special sockets with rubber seals inside. Even greater reliability of the joints is obtained using plumbing sealant - it is only important to ensure that it does not get on the internal surfaces. This can significantly degrade drainage capacity.
4. To secure the plastic apron of the funnel, weldable bitumen is used, placing the product in the required position.
5. Cover the roofing pie with special mastic (bitumen will also work), and then put the protective grill in place.
6. They check the quality of the connections and their tightness - pour a bucket of water about 2 m from the funnel and observe how quickly and in what volume it goes into the drain.
7. If everything is in order, proceed to laying the cladding and further improving the roof.

Filling the apron to seal the system

Video: installation of a drainage funnel

Advantages and disadvantages of products made from various materials

As mentioned earlier, drainage funnels can be steel, plastic, or a combination of these materials. Each of them has strengths and disadvantages that should be taken into account when choosing. Plastic offer the following advantages:

• high anti-corrosion resistance;
• immunity to ultraviolet radiation;
• inertness towards chemicals and biological influences;
• excellent noise absorption;
• slight tendency to become dirty.

The disadvantages include the following:

• not the highest durability;
• exposure to sudden temperature fluctuations, especially if installation is carried out incorrectly.

Steel funnels have the following strengths:

• long period of work;
• good indicators of resistance to external influences;
• excellent strength data;
• high frost resistance;
• Possibility of use in the most difficult climatic and operating conditions.

There are also disadvantages, including:

• complicated installation procedure;
• higher cost compared to plastic counterparts.

Reliable water protection even in the most difficult conditions

It is extremely difficult to overestimate the importance of the drainage funnel and its relevance. Its installation is mandatory for flat roofs, although the installation process itself cannot be called a very simple procedure. It is better to entrust all the work to professionals - they will not only carry out competent calculations, but also arrange effective system drainage in the shortest possible time.

The drainage funnel for a flat roof (fitting) is the main element external system drainage Through it, rain or melt water flows into pipes, which can be installed outside or inside the house, and then into the ground, drainage tank or sewer system. For free drainage of water, the water intake is mounted in the lowest place of the roof. In this case, the minimum slope in its direction is 2°.

Drainage funnel device

Today on the market you can find different kinds drainage fittings, which differ in material of manufacture, design, build quality and cost. Standard design The water intake consists of the following elements:

• body - made of galvanized steel, cast iron or plastic (mounted directly into the roof);
• grid - is a filter element that protects the drain system from contamination;
• downpipe - used to connect the fitting to the drainpipe;
• O-rings and gaskets - allow you to achieve maximum tightness at the junction of the product with the roofing material, thereby preventing moisture from getting under the roof;
• thermal cable - considered additional element, which increases the efficiency of drainage during the cold season, preventing water from freezing near the outlet.

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Types of water intake fittings

Roof drains are classified according to the following parameters:

1. Material of manufacture. Modern water intakes are made from cast iron, galvanized, plastic or a combination of several materials. When choosing a funnel based on this feature, you need to take into account what the roof itself is made of. So, for sheet flooring, the best option is metal fitting, For concrete floor- cast iron, and for soft roof- plastic.
2. Form. Funnels can be flat or bell-shaped. The first type is installed level with the roof plane. Such products need to be periodically cleaned of leaves, branches and other debris, so they can only be installed on roofs that are in use. Bell-shaped products are equipped with a protective mesh that protects the water intake hole from contamination.
3. Design. Fittings for flat roofs can be manufactured as a single piece or consist of two parts connected to each other by a flexible pipe. The second type is used on movable roofs (non-ventilated or wooden). Due to the fact that the components of the funnel can move relative to each other, with any movement of the base, the integrity and tightness of the product is maintained.
4. Bandwidth. Depends on the diameter of the outlet. When choosing a capacity, you need to consider the roof area and the annual rainfall experienced in your area.
5. Method of attachment to the base. A drainage funnel for a flat roof can be attached using a crimping seam or a flexible apron made of roofing felt or thick film. Seam fastening is universal because it can be used with any roofing material.

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Funnel installation procedure

The first step is to choose where to install the fittings. These products are mounted at the lowest points of the roof. At the same time, they must be evenly distributed over the entire surface of the ceiling, which will allow achieving high efficiency of the drainage system.

After choosing a place for the fitting, the hole prepared in the ceiling is installed Bottom part products. The fixation of the funnel to the base should not be rigid in order to exclude the possibility of its damage due to temperature deformations. Next, insulation and waterproofing are laid. Then top part The funnel is attached to the bottom. To improve the tightness, an o-ring seal is additionally mounted. The film apron of the fitting is placed between the lower and top layer roofing felt and secured with molten bitumen mastic.

To avoid the occurrence of stagnant puddles, it is necessary to organize a slope towards the drain holes of at least 2°.

This can be done using a screed or laying a thermal insulation layer of different thicknesses. It should be taken into account that it is not recommended to place the drain near support columns, since deformation shifts are often observed in these places, which can negatively affect the service life of the drainage system. Funnels for flat roofs are installed at the rate of 1 pc. per 150 m 2 of flooring, but their number must be at least two. For example, for a roof with an area of ​​70 m2 you will need 2 fittings, for 100 m2 also 2 pieces. If the roof area is more than 300 m2, then for normal operation For drainage, 3 water intake points should be used.

On last stage work, the finishing layer is laid roofing material, which is inserted into the fitting bowl and secured with a clamping ring. After installing the protective cap, the functionality of the entire structure is checked. To do this, pour a bucket of water near the water intake and observe whether all the liquid gets into the drainage system.

Today in Russia, the majority of residential and administrative multi-storey buildings has a flat roof. Its main function is to protect buildings from precipitation and other external influences. An open roof, along with mechanical loads, is exposed to atmospheric loads in the form of rain and snow, as well as those associated with changes in seasonal temperatures. Therefore, it is necessary to ensure high-quality and timely removal of precipitation and melt water from roofs, for which drainage systems are installed. In Russia, domestic and cast iron/steel risers are mainly used for drainage from flat roofs. A flat roof must be equipped with a drainage system that ensures rapid and complete removal of rain or melt water within all year round.

INTERNAL DRAINS.