Types and installation of drainage funnels for flat roofs. Flat roof drainage: specifics of construction of internal and external options Roof drain funnel

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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-story buildings 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 take into account what type of drainage system will be installed and the material from which the roofing is made. So plastic and metal elements can be used for arrangement internal drain, 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 to create internal system use elements made of asbestos cement.

For the manufacture of longitudinal sections drainage systems Concrete, reinforced concrete, ceramics, asbestos cement are suitable. 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 amounts of precipitation it functions as a gravity structure, and with large amounts of rain or melt water it can easily cope with 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:

Precipitation has a positive effect on vegetation, helps saturate the earth with moisture, beneficial properties and are needed to fill rivers and reservoirs. But, in addition to useful aspects, precipitation has an inactive effect on buildings. Constant exposure can damage concrete, wood and others Decoration Materials. Therefore, it must be purposefully removed from the roof. For this purpose, a special drainage system is used. Roofing drainage funnels play a big role in it. They are the ones who catch the flow of water and direct it through the pipe system.

What are the features of such funnels? How are they different from each other? How to install them correctly? We will learn the answers to these questions from this article.

Types of roof drains

Depending on the roof design, there are different types drainage system. The roofs themselves can be divided into two large groups:

1. Flat roofs.
2. Sloping roofs, with different levels stingray

The drainage system is also divided into two types, based on the roof group:

If we talk about funnels in one and another system, then in the first case it plays a crucial role. Her choice should be treated with special attention. Drain funnel in the photo:

It is precisely these funnels for flat roofs that will be discussed, since gutters horizontal type have built-in funnels that do not need to be selected. We are talking about gravity-vacuum systems. This type of vertical drain was invented more than 30 years ago. His homeland is Scandinavia. Now it is widespread not only in Europe, but also in other countries. The principle of operation is simple, it is based on the so-called ejection ability of liquid in pipes. In this case, one medium carries with it another; in the water drainage system it is air. In the riser, gaseous masses begin to move upward. But when it gets into the system waste water, it is directed downward under the influence of gravity, and the air layer is directed into reverse side. This results in a vacuum environment in which moisture begins to flow through high speed into the collector through a pipe system. The movement of water is determined by pressure from air masses, so a slope is not required for its free movement.

Such a system has many advantages:

1. High flow rate.
2. Can be used to create narrow pipes.
3. The structure will clean itself.
4. The drain is light in weight.
5. For installation, you do not need to do a large amount of excavation work.

The note! If you compare such a vacuum system and a traditional horizontal drain, the difference is immediately visible.

For example, gravity-vacuum type funnels, in which the pipe has a cross-section of 75 mm, can pass through about 15 liters of sediment in just 1 second. But the traditional type system is much inferior, since in order to pass 15 liters of water in one liter, you need a funnel with a diameter of 200 mm.

Materials for making funnels

Internal drainage funnels are made from different materials, which have their own characteristics, advantages and disadvantages. Before you buy a funnel, you need to know this information. Here are the materials the system elements are made from:

Having assessed all the features of each type of funnel, you can choose one or another option.

Product requirements for drainage systems

Installation of the system is specified in GOST 25336-82. The main points are related to the throughput of funnels, as well as their number on a horizontal roof. The roof area for one drainage funnel is specified in SNIP 2.04.01-85, in the section “Internal drains”. So it says there that there should be at least two funnels on the roof and in one valley. The greatest distance between them should be no more than 48 m. It turns out that 1 funnel is required for 230 m2. In this case, its diameter should be 10 cm, no less.

Taking these indicators into account, you need to purchase one or more funnels for your home, and then install them. The roof area per drainage funnel is 230 m2, so you won’t have to spend a lot of money. In addition, it is worth paying attention to the fact that the funnel can become clogged with debris. This includes foliage, dust, and cellophane. To prevent them from penetrating the system and clogging it, a special grill is installed on the roof drainage funnel. She performs protective function, without affecting throughput in any way. However, to ensure that the leaves accumulated on the grate do not prevent water from entering the funnel, you will have to look at the drain from time to time.

Types of funnels for flat roofs

There are several parameters by which storm drains for flat roofs are distinguished. Today, companies produce a variety of models, which makes it easy to choose a product for yourself. So the types are as follows:

Important! Sediment funnels have different sections. Be that as it may, the diameter of the funnel and the drain pipe must match. Typically a section of 10 cm is used. This will be enough to redirect all the water from the roof to storm system.

Installation of a funnel on the roof

Before installing the receiving drainage funnel and other elements of the system, the following nuances should be taken into account:

Now you can begin the installation process. It differs slightly from each other, depending on the roofing covering and the type of funnels. Still, the principle is the same for everyone. We will consider installation on soft roof. The instructions are as follows:

1. To begin with, a niche should be cut around the technological hole. Most homes already have it.
2. Next you need to take the funnel and plant it directly on the concrete. If there is no fold on it, then glue is used.
3. Next you need to apply a buty primer.
4. After that, a soft roof needs to be laid along the cut niche, and then along the entire perimeter.
5. The structure continues to strengthen. The kit includes a fixing ring that needs to be installed in its place and screwed. A hole is cut in the center.
6. All that remains is to install a cap or filter grid for the funnel.

More details about installation can be seen in this video:

As for installing a funnel for a vacuum drain, the installation process can be seen here:

Let's sum it up

The drainage funnel is an integral part of any drainage system. Thanks to it, you can efficiently and quickly drain storm or melt water from the roof surface, flat or sloping. Otherwise, the availability of water will negatively affect everyone structural elements. All that remains is to choose one or another version of the funnel for a flat roof and start installing it. If you have any questions, you can ask them in the comments below the article. Experienced specialists will answer them for you.

Sergey Novozhilov - roofing materials expert with 9 years of experience practical work in the field of engineering solutions in construction.

One of the most destructive factors that shortens the life of a roof is water. However, whatever the design of the roof, there are fairly reliable methods that can effectively withstand precipitation and melt water. In this article we will talk about what drain funnels there are for flat roofs and how to install them correctly.

It is worth noting that roof slopes make it easy to cope with the problem of intense rainfall, since water simply drains from them. But in cases where the roof is completely flat, puddles form on it because the moisture does not have time to evaporate. As a result, the waterproofing undergoes gradual destruction, and a layer of dirt accumulates on the roof surface.

Often wind-blown plant seeds germinate in this layer, further destroying the roofing pie. It is the drainage of melt and rainwater into the system storm sewer and is the main purpose drainage funnels on flat roofs.

What is a drainage system

The term “drainage system” implies a set of devices through which the collection, transportation and removal of melt and rain water from the surface takes place. flat roof.

There are the following types of drains:

1. Unorganized, or natural. In this case, it means that precipitation rolls down steep slopes. For roofs with large slopes, this method is quite acceptable, but it is absolutely not suitable for flat roofs.
2. External. It includes a set of pipes and gutters for water outflow installed on rafter legs or wind boards. Precipitation enters such drains by gravity and is discharged outside into the storm drain. For flat roofs, this type of construction is applicable only in small buildings.
3. Interior. This type of drainage is laid in the thickness of the roofing pie. It is most preferable for flat roofs.

Internal drains for flat roofs

The structure of the internal drainage system suggests the placement of its elements under the insulation and waterproofing layer.

Such a system contains the following components:

• roof funnel – they collect and filter water;
• horizontal pipes - laid under insulation and waterproofing with a slope - for gravity drainage, and without a slope - for vacuum drainage;
• vertical drain pipes - they transport sediment from horizontal pipes to the storm drain.

Depending on the principle of fluid movement, vacuum and gravity drainage systems are distinguished. At vacuum type drain liquid quickly fills the pipe along its entire thickness, forming a continuous column of water. As it moves downward, the air mass tends to rise upward, creating a vacuum. The resulting space, as it were, sucks water from the drain funnel, ensures its rapid removal from the roof surface and prevents the accumulation of debris due to the rapid movement of liquid.

Structure of a drainage funnel

By design, a drainage funnel for a flat roof consists of the following elements:

• the lower section, which is laid into the base of the roofing pie;
• a sealing gasket that seals the joint between the upper and lower sections of the funnel;
• the upper section, which passes through the layer of waterproofing and insulation;
• grate - serves to prevent large debris from entering the drainpipe.

Please note that reliable sealing of the joint between the upper and lower sections of the drainage system funnel is mandatory for the effective operation of the roof. As a rule, it is the penetration of water into the seams of the funnel that causes leaks.

Types of roofing funnels

On sale you can find funnels for flat roofs made of polyvinyl chloride, copper or galvanized steel. The latter are used most often because they differ affordable price. Copper products are too expensive for buyers, so they are not in high demand. In addition, they cannot be combined with any roofing covering. Polyvinyl chloride roofing funnels are used on roofs made of ondulin, shingles and soft tiles.

Based on their structure, the following types of products are distinguished:

1. Flat. Such products are mounted flush with the roof surface covered with asphalt or tiles.
2. Kolpakovaya. This funnel must be equipped with a protective grille to prevent debris and dirt from entering the pipe. The product rises above the surface, resembling a glass or cap.
3. With horizontal or vertical release type.
4. With heating elements. A heating cable is installed inside such a funnel, which melts the snow and prevents the water from freezing and clogging the drain.

Principles for installing a roof drain funnel

Professional craftsmen have developed some standards for correct installation funnels on a soft roof:

• Installation of the device must be carried out in places whose level is below the main surface of the roof. The minimum slope between the funnel and the main roof can be 2º, and over a segment of 50 cm it should increase to 5º. The required slope is created by slabs of insulating material, concrete screed or expanded clay backfill.
• The number of funnels on the surface of a flat roof is determined based on one unit for every 25 m of length.
• Whatever the area of ​​the roof, it must have at least two drainage funnels. They will allow you to withdraw faster a large number of water from the roof if one of the gutters fails.
• The minimum distance between devices is 50 cm, and there must be at least 1 meter to the visor.

Installation sequence on a soft, flat roof

Installation of funnels for removing precipitation from a flat roof is carried out as follows:

• First, the roof is marked, divided into identical geometric shapes. In the central part of each of them, using expanded clay, a layer of insulation and concrete screed, organize a recess. The lower part of the funnel is connected to drainpipe, laid horizontally, and mounted at the base of the roofing pie.
• Upon completion of waterproofing and insulation work, the sealing ring, and the two parts of the funnel are connected.
• The upper part of the device is placed between two layers of roofing material, after which it is fixed with a built-up bitumen apron.
• At the end, a layer of bitumen or mastic is applied, and a protective mesh is installed.
• To make sure that the water inlet funnel is installed correctly and tightly, two meters from it, pour a bucket of water onto the roof and check how quickly all the liquid moves into the drain.

It is worth noting that the drainage system, in particular roof drains, require periodic diagnostics and cleaning. This will significantly extend the life of your roof and will also provide you with rainwater for watering your garden plants.

The main function of drainage systems is to protect the roof and facades from the effects of precipitation, as well as to prevent the destruction of the foundation. The gutter effectively collects and removes water from the roofing surface of the house. It’s no secret that it is thanks to the use of drainage systems service life the façade and roof are increased many times over, appearance remains unchanged.

As you know, the reliability of a roof is primarily determined by its slope, that is, the angle that the slope forms with the horizon. In this case it is usually measured as a percentage. Obviously, if the slope is 0% or so, water should accumulate, and from a roof that has a high slope, water will roll off. Thus, in the first case, leaks and the need for major repairs are inevitable.

Attention!

Water stagnating on the roof, although slowly, but certainly destroys the roofing material. Quickly washing off the surface of the coating material deprives it of its resistance to ultraviolet radiation. .

In a stagnant zone, water, penetrating into defects, also aggravates existing problems.

Gutters

Even when draining, water can linger at the lowest point of the roof, so it is necessary.

They are usually divided into:

The installation location of drainage funnels should be chosen based only on the degree of efficiency of water intake. For example, if you install them near the support columns, due to deformation of the base of the roof, these points, instead of the lowest ones, may well become the highest, especially when the required base slope is not provided.

A huge amount of water accumulates on the roof during heavy rainfalls. There are cases where, due to excessive load on bearing structures, the roof was collapsing. Therefore, an additional drainage system is provided on the roof - a storm drain. By the way, it also helps out when the main drain becomes clogged.

When the water level exceeds a certain maximum (it is primarily determined based on permissible load onto the roof), the storm drain begins to discharge water. Usually, we're talking about about 5-7 cm.

Drain funnel - installation rules

The roof funnel is an element responsible for collecting water. The hull has a wide side. It itself is equipped with an apron or crimp metal flange, as well as a protective grill that prevents clogging of the intake opening.

• Drains are located in the lowest places of the roof, evenly distributed over the surface.
• According to the technology, the minimum slope between the base for installing the roofing carpet and water inlet funnel is 2%, respectively, also in the valley.
• The minimum is increased to 5% at approximately half a meter from the funnel (the thermal insulation is reduced or the screed is leveled). All this must be taken into account in the thermal engineering calculation.
• Regardless of the type of insulation, it is recommended to use two-piece funnels. Since the insulation materials themselves are subject to some movement, the funnel must have some compensatory dynamic reserve.

• Bottom part The roof funnel is installed in the passage hole on the roof slab. The upper part, having passed through the roofing carpet and insulation, enters the lower part. From below it is inserted into a standard drainpipe.
• An O-ring is installed between both parts of the funnel. The funnel at the top is equipped with a small plastic apron. It should be located on the bottom lining layer of roofing felt. Then an additional lining layer is placed, and a bitumen apron is fused on top of it. The roofing pie is completed with a top layer of bituminous roofing material, which is laid on top of the resulting bitumen apron. Lastly, install the protective grille.

Water intake funnels “Polyvent” are fixed on the roof between two layers roofing material, and in the case of a single-layer coating, an additional layer measuring 700mm by 700mm.

1. The bottom layer of roofing carpet is laid.

2. in the lower layer of the roofing carpet in the place where the funnel is to be installed, a hole with a diameter equal to the diameter of the upper part of the funnel flange is cut.

3. the place where the funnel collar will be installed is burned with a burner flame to remove the film covering the roofing material
(if there is one), then poured with hot bitumen binder (hot mastic).

4. A water intake funnel is installed on the bottom layer of the roofing carpet, poured with hot bitumen binder.

5. The top layer of roofing material is fused (or laid in another prescribed manner). Short-term exposure to the flame of a propane burner is allowed top part funnel collar.

6. in top layer roofing material, a hole is cut in the place where the funnel is installed equal to diameter funnel flange inlet.

	is a roof drainage funnel with a leaf filter, made of polypropylene. Designed to remove rainwater from flat roofs. It is not subject to corrosion and has good mechanical properties and can be used in all climatic zones RF. It is recommended to install one such funnel for every 300-400 m² of roof, but at least one per roof.
Specifications
Leg height, mm	245
Weight, kg	0,51
Collar size, mm	380
Inlet D, mm	110
Funnel “REPAIR POLYVENT”	Funnel “REPAIR POLYVENT”- made of polyethylene, which gives them the ability to tightly fit any surface. Used in the repair of roof drainage systems. The funnel foot is inserted into the old roof funnel, or into sewer pipe diameter 100-110 mm. A special insert inside the funnel greatly increases the rate of water intake. The funnels are equipped with a leaf filter.
Specifications
Leg height, mm	240
Weight, kg	0,57
Collar size, mm	297
Inlet D, mm	87
	- inserted into old funnels, including cast iron, with a diameter of 60 to 200 mm to prevent leaves and other debris from getting into them. Thanks to the use of a leaf filter, the internal drainage system does not require constant maintenance. The insert, which is inserted inside the funnel, significantly increases the volume of water received.
Specifications
Diameter of protective grille, mm	160/180
Weight, kg	0,14