Roof funnels for flat roofs. Roof drains HL with vertical outlet. Gutters internal type for flat roofs
One of the most destructive factors that shorten the life of a roof is water. However, no matter what 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 are for a flat roof, and how to properly install them.
It is worth noting that the slopes of the roofs make it easy to cope with the problem of intense precipitation, since water simply flows off them. But in those cases when the roof is absolutely flat, puddles form on it, since the moisture does not have time to evaporate. As a result, the waterproofing is subject to gradual destruction, and a layer of dirt accumulates on the roof surface.
Often, wind-blown plant seeds germinate in this layer, which further destroy the roofing cake. It is the removal of melt and rain water into the system storm sewer and is the main purpose of drain 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 rainwater from the surface of a flat roof takes place.
There are such types of drains:
- Disorganized, 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.
- External. It includes a set of pipes and gutters for the outflow of water, installed on rafter legs or wind boards. In such drains, precipitation falls by gravity and is discharged out into the storm sewer. For flat roofs, this type of construction is applicable only in buildings of a small area.
- Interior. This type of drain is laid in the thickness of the roofing pie. It is most preferred for flat roofs.
Gutters internal type for flat roofs
The structure of the internal drainage system offers 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 a gravity drain, and without a slope - for a vacuum one;
- vertical sewers - they transport precipitation from horizontal pipes to the storm drain.
Depending on the principle of fluid movement, there are vacuum and gravity drainage systems. At vacuum type the drain liquid quickly fills the pipe throughout its thickness, forming a continuous water column. As it moves down, the air mass tends to rise up, creating a vacuum. The resulting space, as it were, sucks in 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 the liquid.
The structure of the catchment funnel
By design, a catchment funnel for a flat roof consists of the following elements:
- the lower section, which is laid in the base of the roofing cake;
- sealing gasket sealing the joint between the upper and lower sections of the funnel;
- the upper section that passes through the layer of waterproofing and insulation;
- grate - serves to prevent large debris from entering the downpipe.
Please note that reliable sealing of the joint between the upper and lower sections of the funnel of the drainage system is mandatory for the effective operation of the roof. As a rule, it is the ingress of water into the seams of the funnel that causes leaks.
Varieties of roof funnels
On sale you can find funnels for flat roofs made of polyvinyl chloride, copper or galvanized steel. The latter are the most commonly used because they differ affordable price. Copper products are too expensive for buyers, so they are not in high demand. In addition, they can not be combined with any roofing. Polyvinyl chloride roof funnels are used on roofs made of ondulin, shinglas and soft tiles.
According to the structure, the following types of products are distinguished:
- Flat. Such products are mounted flush with the roof surface, covered with asphalt or tiles.
- Kolpakova. This funnel is necessarily equipped with a protective grill that prevents debris and dirt from entering the pipe. The product rises above the surface, resembling a glass or cap.
- With horizontal or vertical type of release.
- With heating elements. Inside such a funnel is mounted heating cable, 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 soft roof:
- Installation of the device must be carried out in such places, the level of which is lower than the main surface of the roof. The minimum slope between the funnel and the main roof can be 2º, and in a segment of 50 cm it should increase to 5º. The necessary slope is created by plates of insulating material, concrete screed or expanded clay backfill.
- The number of funnels on the surface of a flat roof is determined on the basis of one unit for every 25 m of length.
- Whatever area the roof is, it must have at least two drain funnels. They will allow you to quickly remove a large amount 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 out by dividing it into identical geometric shapes. In the central part of each of them with the help of expanded clay, a layer of insulation and concrete screed, organize a deepening. The lower part of the funnel joins with a downpipe laid horizontally and is mounted at the base of the roofing pie.
- Upon completion of waterproofing and insulation work, a sealing ring is laid, 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 also mounted.
- To make sure that the water intake funnel is installed correctly and tightly, a bucket of water is poured onto the roof two meters from it and they check how quickly all the liquid will move into the drain.
It is worth noting that the drainage system, in particular roof funnels, needs periodic diagnostics and cleaning. This will significantly extend the life of your roof, as well as provide you with rainwater to water your garden plants.
January 3, 2018
Specialization: philological education. Experience as a builder - 20 years. Of these, for the last 15 years he led a brigade as a foreman. I know everything about construction - from design and the zero cycle to interior design. Hobbies: Vocal, psychology, quail breeding.
Greetings, my dear readers!
Now flat roofs, which were previously used for industrial, utility and high-rise buildings are also used in domestic construction. Such a roof provides free space on which you can place winter Garden, sports ground, terrace, etc. To protect the roof from atmospheric moisture, it must be equipped with an exhaust system. Its central element is a drain funnel for a flat roof.
Types of roof drainage systems
Roof drains are divided into two types:
- outdoor system. It is mounted along the perimeter pitched roofs and very rarely flat analogues. Horizontal gutters and vertical gutters are used to drain water.
- Internal network. It is designed for flat roofs.
Internal drainage systems are divided into two types:
- Gravity (traditional, gravity) network. For it, you need to mount a lot of funnels, moisture is drained through the pipes by gravity. For the proper functioning of the gravity system, it is necessary to properly form slopes on a flat roof. Funnels are placed on the lower sections. The number of water inlets depends on the area of the roof.
Funnels with the help of pipes are mated with a vertical riser. Through it, water is discharged into a storm drain. The horizontal pipes of the network are laid with an inclination so that the water can flow away by gravity.
- Siphon-vacuum system. It has a high throughput with a minimum structural elements. In funnels with siphons, a vacuum environment is recreated. Due to this, the liquid is absorbed from the roofing and flows through the communications very quickly.
Advantages vacuum system sewerage:
- the discharged water flows have a high speed;
- ease of installation - few water inlets and pipes are needed to equip the network;
- low weight - the system does not create heavy loads on the roof;
- efficiency - water intakes and communications of a smaller section are used than in a gravity system;
- the system is self-cleaning, so the network throughput indicators are unchanged during its operation.
The water inlet of the vacuum network with a horizontal branch pipe with a cross section of 7.5 cm passes up to 16 liters of moisture per second. In order for the gravity system to have the same throughput, funnels with outlets with a diameter of 20 cm will have to be mounted.
The design of the water intake funnel
The water intake funnel is the main element of the roof storm sewer. Through it, melt and rain moisture is removed from the roof. Further, the liquid flows into the stormwater pipes laid inside the building. On them, it is dumped on the ground or into the drainage sewer.
A modern funnel for draining water consists of the following parts:
- Lid. She covers the top of the product.
- Lattice. Protects the drain from contamination and the penetration of foreign objects into it.
- Sealing ring. This element gives the funnel tightness.
- Release. This branch pipe can be horizontal or vertical.
- water bowl. Liquid flows into it, which is then redirected to the drain.
- Stuffing box. It seals the junction points of the downpipe with the outlet.
- Flange or bolt. These elements secure the funnel.
Classification of water intakes
Flat roof water inlets are classified according to several parameters. Now manufacturers produce many of their models, so it will not be difficult for you to choose the right product.
A flat roof with an internal drain, based on its features, can be equipped with funnels of the following types:
| Image | Funnel type |
 |
Kolpakovaya.
This type of water inlet is equipped with a convex protective mesh, very similar to a cap. Such a water intake copes well with large volumes of water flows. The mesh effectively filters the liquid from foreign objects. |
 |
flat.
Such a funnel is installed flush with the roofing. Particularly effective are flat water inlets on exploited roofs lined with paving slabs or asphalt concrete. |
 |
heated.
An electrical cable is placed inside such a funnel. It provides heating of the network in winter. Thanks to this, the drainage system is not clogged with frost. |
 |
One or two stage water inlet.
The first variety is used on roofs with a rolled polymer or bitumen coating. The second type is used on roofs that are subject to movement (non-ventilated and wooden). |
 |
Water inlet equipped with or without a rebate.
This crimping element is a universal fastener that is suitable for all types of base. Funnels without a fold are equipped with an apron made of film or roofing felt. They are selected based on the type of roofing. |
 |
Funnel with vertical, horizontal or hinged outlet.
Water from such outlets flows through pipes placed along or across the walls of the building. A vertical water inlet is used for a conventional flat roof. The horizontal analogue is optimal for roofs without an attic. Pivoting water inlets can be connected to the storm riser at any angle up to 90˚. |
The funnel for water can have a different section. But in any case, it must match the diameter of the drain. Most often, water inlets with a diameter of 10 cm are used. This size is enough for the speedy discharge of large volumes of liquid from roofs of different sizes.
Funnel materials
Water intake funnels are made from the following materials:
- Plastic. The basis of such devices is a durable polymer that is resistant to mechanical stress and external influences. Installation of plastic water inlets is quite simple, it does not need glue.
This option is optimal for installation on a roof that is not in use or used infrequently.
- Steel. It is another common water intake material. Metal water inlets have high strength. Therefore, they can be mounted on exploited roofs with high level patency.
Most often, metal funnels are made of galvanized or stainless steel. Such material is quite reliable, tough, durable, resistant to deforming loads and corrosion.
- Composite. In this case, the funnel is made from a combination of a pair of materials, usually metal and plastic. The body of the water intake is made of plastic, and the protective grille is made of cast iron or stainless steel.
Composite products are used on roofs with an average level of traffic and moderate mechanical loads.
Conclusion
Funnels for flat roofs make it possible to drain melt and storm water from them. There are many types of them. Therefore, you can always choose the water inlets that are best suited for the roof of your house.
If you have any questions, ask them in the comments. I say goodbye and good luck in your endeavours.
January 3, 2018If you want to express gratitude, add a clarification or objection, ask the author something - add a comment or say thanks!
Roof drains HL with vertical outlet- HL 62, HL 62.1 and others are used for different types of flat roofs, both for non-exploited and exploited ones. Roof drains HL are used with various designs(types) of roofing and filling the "pie" of the roof. Mounted on operated inversion roofs, insulated flat traditional roofs, roofs from a professional flooring (professional sheet), "green roofs", can be installed on balconies and terraces. HL funnels are designed to drain rain and melt water from roofs to rain sewers.
This section presents:
HL drains with vertical outlet for unused roofs. With leaf catcher. DN - 75, 110, 125 or 160;
Roof drains HL with vertical outlet for roofs in use. With grid (150x150 mm) in stainless steel. DN - 75, 110, 125 or 160;
HL drains with vertical outlet for corrugated roofs. DN - 75, 110, 125. For installation in roofs with insulation thickness - 100-160 mm.
Additional equipment for roof drains HL - extensions, extensions, waterproofing flanges, various leaf catchers, fire couplings.
HL drains with vertical outlet for unused roofs. With leaf catcher. Sizes - DN 75, 110, 125 or 160.
|
Description |
|||
|
Roof drain with leaf catcher, thermally insulated, with stainless steel compression flange (with union nuts/wing nuts), with vertical outlet. Recommended for waterproofing polymeric membranes: EPDM, EPB, ECB (ethylene-copolymer-bitumen), EVA (ethylene-vinyl acetate), PIB (polyisobutylene), etc. |
|||
|
Like roof drain HL 62, but electrically heated. Self-regulating heating cable. Power - 10-30 W. Voltage - 230 watts. |
|||
|
HL62P |
 |
Roof outlet with leaf catcher, PVC (polyvinylchloride) body with thermal insulation for bonding PVC membrane, with vertical outlet. Recommended for PVC membranes. |
|
|
Like roof drain HL 62P, but electrically heated. Self-regulating electric heating cable with a power of 10-30 W, 230 V. |
|||
|
HL62 F |
 |
Roof drain with leaf catcher, with body made of PP with thermal insulation for gluing waterproofing FPO membranes. With vertical outlet. Recommended for FPO membranes (based on PP). |
|
|
HL 62.1F |
 |
Like roof drain HL 62F, but electrically heated. Self-regulating electric heating cable with a power of 10-30 W, 230 V. |
|
 |
Roof funnel with leaf catcher, body made of thermally insulated PP, with waterproofing polymer bitumen sheet 2.5 mm thick and 500 mm in diameter. Recommended for weldable waterproofing materials bitumen based. With vertical outlet. |
||
|
Like roof drain HL 62H, but electrically heated. Self-regulating heating cable. Power - 10-30 W. Voltage - 230 watts. |
|||
|
"Universal" funnels for non-exploited roofs with a leaf catcher. With universal connection to steel, cast iron, plastic pipes. |
|||
|
"Universal" roof drain, with leaf catcher, with stainless steel compression flange (with union nuts/"wing nuts"), with flexible sealing rings, with vertical outlet. This funnel simply and reliably connects to pipes made of any material (steel, cast iron, plastic). The funnel is inserted into the pipe and does not require compensatory nozzles. |
|||
|
HL69P |
|
"Universal" roof drain, with leaf catcher like HL 69, but with PVC flange, for fixing PVC membrane, drain with flexible sealing rings, with vertical outlet. Funnel HL 69P is simply and securely connected to pipes made of any material (steel, cast iron, plastic). It is inserted inside the pipe and does not require compensation pipes. Recommended for waterproofing polymeric membranes: EPDM, EPB, ECB (ethylene-copolymer-bitumen), EVA (ethylene-vinyl acetate), PIB (polyisobutylene), etc. |
|
|
HL69H |
 |
"Universal" roof outlet, with leaf catcher as HL 69, but with bituminous polymer mesh, with flexible sealing rings. With vertical outlet. The funnel is connected to pipes made of any material (steel, cast iron, plastic). The funnel is inserted into the pipe and does not require compensatory nozzles. Recommended for waterproofing polymeric membranes: EPDM, EPB, ECB (ethylene-copolymer-bitumen), EVA (ethylene-vinyl acetate), PIB (polyisobutylene), etc. |
|
Roof drains HL with vertical outlet for roofs in use. With 150x150 mm stainless steel grate. Sizes - DN 75, 110, 125 or 160.
|
Description |
|||
|
HL 62B |
 |
Thermally insulated roof drain with stainless steel compression flange (with union nuts/wing nuts). With vertical outlet. Recommended for waterproofing polymeric membranes: EPDM, EPB, ECB (ethylene-copolymer-bitumen), EVA (ethylene-vinyl acetate), PIB (polyisobutylene), etc. |
|
|
Like roof drain HL 62B, but electrically heated. Self-regulating electric heating cable 10-30 W, 230 V. |
|||
|
HL62BP |
|
Thermally insulated roof drain with PVC (polyvinyl chloride) body, for gluing PVC membranes, with vertical outlet. Recommended for roofs with PVC membrane waterproofing. |
|
|
HL 62.1BP |
|
Like roof drain HL 62BP, but electrically heated. Self-regulating electric heating cable 10-30 W, 230 V. |
|
|
HL62BF |
 |
Roof drain with thermal insulation, with body made of PP (polypropylene) for gluing FPO sheeting. With vertical outlet. Recommended for serviced roofing with FPO-membrane (PP-based) waterproofing. |
|
|
HL 62.1 BF |
|
Like roof drain HL 62BF, but electrically heated. Self-regulating heating cable. Power - 10-30 W. Voltage - 230 watts. |
|
|
HL 62 BH |
 |
Roof funnel with thermal insulation, with a waterproofing polymer-bitumen sheet 2.5 mm thick and 500 mm in diameter. With vertical outlet. Recommended for built-up waterproofing materials based on bitumen. |
|
|
HL 62.1 BH |
|
Like roof outlet HL 62 BH, but electrically heated. Self-regulating heating cable. Power - 10-30 W. Voltage - 230 watts. |
|
|
"Universal" drains for roofs in use with grating (150x150 mm) made of stainless steel. with universal connection to steel, cast iron, plastic pipes. |
|||
|
HL 69 V |
 |
"Universal" roof drain, with leaf catcher, with stainless steel compression flange (with union nuts/"wing nuts"), with flexible sealing rings, with vertical outlet. The funnel is simply and reliably connected to pipes made of any material (steel, cast iron, plastic). The funnel is inserted into the pipe and does not require compensatory nozzles. |
|
|
HL69BP |
 |
"Universal" roof drain, with leaf catcher as HL 69 B, but with PVC flange, for fixing PVC membrane, drain with flexible sealing rings, with vertical outlet. Funnel HL 69 BP connects to pipes made of any material (steel, cast iron, plastic). It is inserted inside the pipe and does not require compensation pipes. Recommended for waterproofing polymeric membranes: EPDM, EPB, ECB (ethylene-copolymer-bitumen), EVA (ethylene-vinyl acetate), PIB (polyisobutylene), etc. |
|
|
HL69BH |
 |
"Universal" roof drain, with leaf catcher as HL 69 B, but with bituminous polymer waterproofing membrane, with flexible sealing rings. With vertical outlet. The funnel is connected to pipes made of any material (steel, cast iron, plastic). The funnel is inserted into the pipe and does not require compensatory nozzles. Recommended for waterproofing polymeric membranes: EPDM, EPB, ECB (ethylene-copolymer-bitumen), EVA (ethylene-vinyl acetate), PIB (polyisobutylene), etc. |
|
Funnels with vertical outlet for corrugated roofs. DN - 75, 110, 125. For installation in roofs with insulation thickness - 100-160 mm.
|
Description |
|||
|
Roof funnel for corrugated roofs, with a leaf catcher, with a stainless steel compression flange (with union nuts/wing nuts), with thermal insulation, with a sliding mounting box (adjustable in height - 100-160 mm). With vertical outlet. Recommended for waterproofing polymeric membranes: EPDM, EPB, ECB (ethylene-copolymer-bitumen), EVA (ethylene-vinyl acetate), PIB (polyisobutylene), etc. |
|||
|
Like roof drain HL 63, but electrically heated. Self-regulating heating cable. Power - 10-30 W. Voltage - 230 watts. |
|||
|
HL63P |
 |
Roof drain for corrugated roofs, with leaf catcher, with thermal insulation, with sliding mounting box (adjustable in height - 100-160 mm) like HL 63, but with a smooth PVC flange, for attaching a PVC membrane. With vertical outlet. Recommended for PVC membranes, lightweight corrugated roofs, with insulation thickness - 100-160 m. |
|
|
HL 63.1P |
|
Like roof drain HL 63 P, but electrically heated. Self-regulating heating cable. Power - 10-30 W. Voltage - 230 watts. |
|
|
HL63H |
 |
Roof funnel for corrugated roofs, with leaf catcher, with thermal insulation, with sliding mounting box (adjustable in height - 100-160 mm) like HL 63, but with a waterproofing bituminous polymer sheet. With vertical outlet. It is recommended for built-up waterproofing materials based on bitumen, lightweight corrugated roofs, with insulation thickness - 100-160 m. |
|
|
HL 63.1H |
|
Like roof drain HL 63 H, but electrically heated. Self-regulating heating cable. Power - 10-30 W. Voltage - 230 watts. |
Accessories for roof drains with vertical outlet series HL 62
|
Description |
|||
|
Extensions for funnels series HL 62 |
|||
|
Extension element with a stainless steel compression flange and a sealing rubber ring, 345 mm high, used for hermetic connection with waterproofing, as well as with a roof funnel on flat insulated roofs with a vapor barrier, DN 125 |
|||
|
An extension element with a waterproofing polymer-bitumen sheet and a sealing rubber ring, 345 mm high, is used for hermetic connection with bitumen-based waterproofing, as well as with a roof funnel on flat insulated roofs with a vapor barrier, DN 125. |
|||
|
HL65P |
 |
Extension element made of polyvinylchloride, with a sealing rubber ring, 345 mm high, is used for hermetic connection with waterproofing from PVC membranes, as well as with a roof funnel on flat insulated roofs with a vapor barrier, DN 125. |
|
|
HL65F |
 |
Extension element made of polypropylene, with a sealing rubber ring, height 345 mm, used for hermetic connection with waterproofing made of FPO sheet, as well as with a roof funnel on flat insulated roofs with a vapor barrier, DN 125. |
|
|
HL65PE |
 |
Polyethylene (PE) extension for gluing FPO membranes (PE-based). |
|
|
HL 350.0 |
 |
An extension element with a profiled flange is used for mechanical fastening (pickup) of the second level of waterproofing. Height - 220 mm. DN 145. |
|
|
HL 350.1 |
 |
Extension piece with stainless steel compression flange, PP drain ring to receive water flow and installation kit, used for bituminous waterproofing. Height - 220 mm. DN 145. |
|
|
HL 350.1H |
 |
An extension with a waterproofing polymer bitumen sheet, used to pick up the second level of waterproofing, 225 mm high, DN 145 |
|
|
Funnel extensions for HL 62 series |
|||
|
Extension for roof outlets and extension element HL350.0, height 155mm. DN 145. |
|||
|
HL 350.2 |
 |
HL 350.1 with additional side outlet. DN 40. |
|
|
Waterproofing flanges for funnels series HL 62 |
|||
|
HL 84 |
 |
Waterproof flange with EPDM membrane 500x500 mm for roof drains. |
|
|
HL 84.0 |
 |
Ø 220 mm stainless steel waterproofing crimp flange for roof drains. |
|
|
HL 84.CU |
|
Waterproofing flange with copper sheet 500x500mm, for roof drains. |
|
|
HL 84.E |
Waterproofing flange with galvanized steel sheet 500x500mm for roof drains. |
||
|
Leaf catchers for funnels series HL 62 |
|||
|
HL 160 |
 |
Drainage flange for receiving water flow from waterproofing to inverted roof. Ø 170 mm. |
|
|
HL 161 |
 |
Drainage flange HL 160 complete with adapter Ø145 mm to Ø125 mm. |
|
|
HL 170 |
 |
Flat leaf catcher for roof outlets of the HL 62 and HL 64 series. Ø 170 mm. |
|
|
HL 175 |
Stainless steel leaf catcher for HL 62 and HL 64 series roof drains. Ø 145 mm. |
||
|
Fire couplings for HL 62 series funnels |
|||
|
HL 850 |
 |
Fire coupling for funnels of the HL 62 (DN 75) series, fire resistance EI 120, consisting of a metal body with expanding material and a yoke, with a mounting plug. Applies to DN 75 outlets only. |
|
|
HL 870 |
 |
Fire coupling for roof drains series HL 62 (DN 110), fire resistance EI 45, consisting of a metal body with expanding material and a yoke, with a mounting plug. Applies to DN 110 outlets only. |
|
A modern flat roof drain funnel is not just a hole in the roof, it is a complex drain structure. Next, we will analyze which roof drain funnels are better in a given situation, what they are made of, and most importantly, I will show in the photo step by step installation funnel in three ways.
For a flat roof, special types of roof drain funnels are used.
Varieties and technical data of storm funnels
Absolutely on all roofs a storm water collection and drainage system is installed. The choice of drainage system depends on the angle of inclination and the configuration of the roof.
Types of roof drainage systems
Despite the variety of roofs, professionals divide them into 2 directions - pitched and flat. For each direction, their own types of drain systems are used, respectively, and their water intake funnels are different.
- Pitched - if the roof has a slope of more than 10º, then it belongs to the pitched direction. The principle of operation for pitched drainage systems is the same - a gutter is mounted around the perimeter of the roof, which collects water, and through funnels and drainpipes this water is discharged to certain points;
According to the rules on pitched drainage systems, one water intake funnel is mounted on no more than 10 m of a continuous gutter
- The drainage system of a flat roof is an order of magnitude more complicated than that of a pitched “sister”, therefore several drain wiring schemes are used here and different funnels for a flat roof are recommended for each scheme.
Important! Such roofs are conventionally called flat, there is a slope there in any case, usually the angle ranges from 3º - 10º. Slopes are needed to collect water at certain points with funnels.
On any flat roof, a slope is arranged to collect water in funnels
Classification of water intakes
On flat roofs, all drain systems are regulated according to GOST 25336-82, there is a lot of information there, but we, at the amateur level, are interested in 2 main characteristics:
- Capacity of water intake funnels;
- Quantity per m2
The issue with the number of water intake funnels per 1 m² is easily solved. The standard indicates that with a thickness drain pipe 100 mm, one is installed for every 200 m² drain funnel. It is mounted either in the center or closer to one of the sides of the catchment sector.
With regard to throughput, then on flat roofs, drainage systems are divided into 2 types:
- Traditional or conventional drains have a drain hole diameter of at least 100 mm. Water in them goes by gravity, while the pipe is never completely filled. The system is used on small roofs with simple funnels;
With a relatively small cross-section of pipes, the siphon-vacuum drainage system, in comparison with the usual one, has an efficiency factor 2 times higher
- In siphon-vacuum systems, drainpipes are completely filled and with a small pipe cross-section, the throughput is an order of magnitude higher. Due to the structure of the funnel and the configuration of the piping, a vacuum is created and water is sucked in more strongly. The principle of operation is the same as when draining fuel from the tank of the car.
In the siphon-vacuum system, the main element is a two-level funnel, it is this funnel that ensures the filling of the pipe with water and the suction effect
| Illustrations | Types of water intakes |
 |
Cap funnels are easy to recognize by the presence of a grid rising above the drain, it is designed to protect the drain from debris. |
 |
The top cap of such a drain is mounted flush with the roofing. These funnels were developed for exploited roofs, so the structures are highly durable. With proper installation, some models are able to withstand loads up to 250 kg. |
 |
In such models, internal heating of problem nodes is provided. As a result, the structure is not clogged with ice in the off-season, and most importantly, it does not break in severe frosts. |
 |
Layered Models
In fact, there are only one and two-level plums. The first is mounted in traditional systems, and the second in vacuum. In addition, two-level funnels are designed to be installed on an unstable base, for example, on an open terrace of a wooden house. |
 |
These models appeared relatively recently, in which the outlet pipe can change the angle of inclination up to 90º, which is convenient when arranging a private house, where it is not always possible to clearly follow the project. Plus, the hinges are universal, they can be used both for vertical and horizontal systems, and for inclined pipelines. |
Funnel materials
- Plastic — plastic plums are considered the most affordable, but this is perhaps their only advantage. One of the places where the installation of such models is justified is small technical buildings with corrugated roofing or something similar;
- Steel- such plums are considered the most durable and durable. They can be mounted both on reinforced concrete, and on wooden or other movable ceilings. The price of models made of galvanized steel is lower, but over time, the zinc peels off and they corrode, so it is better to take stainless steel or cast iron;
In addition to steel, plastic and combined funnels, cast-iron models are widely used in the public sector, of course they are heavy, but strong, durable and inexpensive.
- Combined– here we are dealing with a successful symbiosis of stainless steel and modern polymers. In such models, the loaded nodes are made of steel, and the polymer is used to protect the structure from the aggressive effects of drains.
Self-installation of the funnel - 3 ways
For flat roofs, different drainage systems are used, respectively, and roof funnels on these systems are mounted differently.
Method number 1. Installation of a siphon-vacuum drain
| Illustrations | Recommendations |
 |
Step 1
For example, we took one of the popular Geberit Pluvia models, other market leaders use a similar instruction. To begin with, a square bed is cut out in the concrete roof for the structure. |
 |
Step 2
Lubricate the niche with glue and immerse the base of the funnel there; · There is a metal plate on top of the funnel, it must be rotated 90º and holes for the anchor must be drilled in the roof, as shown in the diagram on the left. |
 |
Step 3 We fix the plate from 4 sides with anchors or powerful dowel-nails. |
 |
Step 4 There are studs on the base, and a rubber gasket is included with the model. This gasket must be put on the studs. |
 |
Step 5 A soft roof is rolled over the protruding studs, for example, TechnoNIKOL, after which holes for the studs are cut into it. |
 |
Step 6
A ring is put on the studs and fixed with nuts.
|
 |
Step 7 Nuts are tightened without fanaticism. The fact is that the gasket has sealing ribs and it is not desirable to completely flatten them. |
 |
Step 8 Cut out the soft roof from the funnel. |
 |
Step 9 The cap consists of three nodes, the first is installed outer mesh, for this, there are 2 hooks on the basis. |
 |
Step 10 Now insert the core until a characteristic click. |
 |
Step 11 The top cover is put on and fixed in the same way as the two previous ones, that is, until a characteristic click. |
Method number 2. Drainage for old houses
Important! In old high-rise buildings, it makes no sense to install a gravity-vacuum funnel. Because besides it, there is also a pipe wiring under the drain that needs to be mounted according to a special scheme. Therefore, for old houses, other models are used, by the way, cheaper ones.
| Illustrations | Recommendations |
 |
Step 1 Here, in the concrete floor, it is also necessary to equip a bed, but I am glad that this bed already exists in the old Khrushchev houses and other multi-storey Soviet projects. |
 |
Step 2 If the roof is not operated in any way, then the funnel can be taken the simplest. For its fastening, glue "Emaco S88" or a similar composition is used. |
 |
Step 3 Immerse the cuff of the funnel in glue and once again coat it with glue on top. |
 |
Step 4 Now the entire bed, up to the very studs, is covered with bituminous mastic. Previously, ordinary bitumen was used, now Izobit BR from the Izolex trademark is used. |
 |
Step 5 A couple of layers of TechnoNIKOL soft roof are laid on the Izobit BR bitumen primer, and a fixing ring is installed and screwed on top. |
 |
Step 5 The cap is inserted last, most models are mounted in the same way, until a characteristic click. |
Method number 3. Drain for lightweight roof with insulation
A lightweight roof is a roof made of corrugated board, on top of which a heater is laid and all this is covered with a TechnoNIKOL soft roofing membrane.
| Illustrations | Recommendations |
 |
Step 1 The roofing pie is disassembled and a drain hole is cut in the corrugated board. |
 |
Step 2 The insulation is two-layer and the funnel is two-level, so we cut out a bed for each level with a reciprocating saw. |
 |
Step 3 We roll out a layer of waterproofing and cut a hole in it for a funnel. |
 |
Step 4
We choose a funnel model with soft cuffs, otherwise the funnel may crack from the movement of the soft base. Roofing membrane "TechnoNIKOL" warms up gas burner, after which the cuff is pressed against the base. |
 |
Step 5 Now we take a square (1 × 1 m) of the TechnoNIKOL finishing membrane, put it on a funnel and cut a hole. |
 |
Step 6 Then we heat up the membrane and glue it on the funnel, after which you can lay the finishing layer of the TechnoNIKOL roof (it is also welded with a burner). On the last step cap is inserted. |
Conclusion
Roof funnels are an important structural element in organizing a drainage system. Their main purpose is to receive moisture and redirect it from the roof surface to the drainpipe. This prevents excess accumulation and prolongs the life of the roofing carpet. The performance of roof drains is affected by several factors at once: this is the throughput and diameter, which are closely interconnected. The installation technology of different brands remains unchanged. As additional elements, a leaf catcher, an adapter for pipes and funnels with different diameters, additional roof fasteners for installation, an electric heating system or a knee to turn a direct-flow drain into a horizontal one may be required. A leaf catcher to protect pipes from blockages and a cable to prevent freezing can be included in the basic package. It is enough to compare different brands funnel for flat roofs Termoclip.