Buildings with a flat roof, which are so familiar for multi-story and industrial buildings, are increasingly found in private housing construction. This type of roof allows you to get additional space for a terrace, pool, sports ground or garden.
In order for the roofing to be reliably protected from damage under the influence of moisture, it is necessary to provide a system for draining rain and melt water, taking care of the competent installation and heating of the funnels.
Appointment
Gutters funnels save a flat roof from the main enemy - water. It has a destructive effect on materials and causes a reduction in the life of roofing. All this leads to leaks. If we consider hip, gable and single-pitch roofs, they are able to withstand rain and melt water. Their slopes due to the slope do not allow moisture to linger on the surface, water slides down.
As for flat roofs, they need drain funnels that help remove water. Puddles on the surface do not accumulate, and the flat roof is protected. Stagnant water can destroy waterproofing, which is affected by dust and marshy substrate.
Additionally, the need to use
The seeds of plants fall into the fertile "soil", which gradually germinate and destroy the roofing cake with their roots. Gutters are installed on flat roofs to avoid such consequences. Such systems remove excess moisture into a storm sewer.
Device
Funnels for the internal drain can be made of different materials - metals, polymers or their combinations. Products must be selected taking into account the type of material that was used to equip the roofing cake. Metal funnels are used on roofs that are covered with sheet metal. For installation on soft roofs suitable polymer products.
The funnel may have a rectangular or round shape. The release may be vertical or horizontal. The choice of the model of the drain funnel depends on the features of the roof. Products can be classified by type of construction, but the funnel can be rigidly fixed to the roof, providing reliable waterproofing of the mount. If you choose a device with a steel flange, it can be strengthened using stainless steel elements using the clamping method. If the model is equipped with a polymer flange, then the design will be supplemented by a sealing sleeve. Mounting in this case is done by glue.
What else is important to know about the device
Gutter funnels for the roof must be protected from clogging. In order to prevent large debris from entering the drain, the funnel is supplemented with a net or a protective cover, otherwise the stagnation of the entire system cannot be avoided. The latter can be flat, it has slots and is used on operated roofs. Such covers are so reliable that they can withstand the weight of a person. If you want to equip a green roof, it is best to choose a model with a filter for leaves. It has the appearance of a mesh hood.
Settlement
Before purchasing products for arranging a roof drainage system, it is necessary to calculate the number of funnels. The formula here is very simple: approximately 0.75 m 2 of roof should be per funnel. To drain, you must allocate 1 cm of pipe area.
Installation of the internal drainage system is not recommended to be carried out on the external walls, because in winter you may encounter freezing, which will negatively affect the system’s performance. It may seem to you that, having determined the area of the roof, you will find out the number of funnels and purchase suitable pipes. However, not all so simple. It is important to take into account some of the nuances that are observed when finding the number of funnels. For example, for linear expansion of the gutter of 12 mm in the absence of obstacles, one funnel can be installed. If its length is longer, but something is hindering the expansion, an auxiliary funnel should be installed at the end of the slope, which will be compensating.
When moisture is collected around the entire perimeter of the roof, the funnels will have expansion joints. The number of water intake devices must match the number of pipes. When calculating, the passport data of the building should be used. In addition to the drainage elements, you must choose the size of the pipes. To do this, it is necessary to examine the object and identify its architectural features, for example, depressions or protruding parts.
The number of pipes can be selected using a simple formula: 100 millimeters in diameter will be enough for a roofing surface of up to 200 m 2 . The slope of the roofing plane is also important. With increasing degree, the side of the gutter rises.
For internal flow it is necessary to determine the cross-section of the pipe. This value is as follows: the roof area must be multiplied by the amount of rainfall. You can find the last value in the table, which shows statistics on precipitation over several years for a particular region. If this method does not suit you, you can use the old one. To do this, the pipe cross section is selected for consideration: one square meter of the roof should be per 1 square centimeter of the pipe.
Installation Rules
Flat drain funnels are installed below the main level of the roof. Between the base and the funnel, it is necessary to observe a slope of 2 °. At a distance of 50 cm, the slope must be increased to 5 °. This effect can be achieved with expanded clay, insulation boards or concrete. Funnels should be distributed evenly over the roof surface. At 25 m in length, one piece must fall.
Regardless of what the roof area is, the minimum number of drain funnels should be 2. This is due to the fact that in the event of a blockage in the drain or during heavy rains, the second funnel will insure a failed one or one that does not cope with a large volume of water. The smallest distance should be maintained between the funnels, which is 50 cm. 1 m must be retreated from the edge of the roof.
Installation technology
To install, the roof surface must be divided into geometric shapes. After laying the insulation and the waterproofing layer, the upper part of the funnel must be connected to the bottom using an O-ring. Between the lower and upper layer of roofing material is a plastic apron, which is located on the top of the funnel. The next step is to cover the roofing pie with bitumen or mastic, and then install the protective grill.
Funnel manufacturers
HL gutters are available in a wide range. They can have a vertical outlet and leaf catchers, such as the model HL62. This device has thermal insulation and is made of stainless steel. It has a crimp flange.
If you want to buy a funnel from another material, then you should choose the model HL62.1P, which is made of polyvinyl chloride. The model has a vertical outlet and has electric heating. There are also articles made of cast iron, which are produced by the Moscow company Obstroytekh. An example of such a model is BP-100, the nozzle diameter of which is 100 mm. Between the mounting holes is maintained at a distance of 230 mm. In the scope of delivery of the BP drainage funnel:
- clamping flange;
- drain pipe;
- cap to cap;
- cap to the funnel;
- set of hardware.
This model is universal and can be installed on rollless and roll roofs of any design. Their thickness should be equal to 150 mm or more. Such a drainage cast-iron funnel has a diameter of 320 mm. It can be used on the roofs of industrial and public buildings. Some of these models have electric heating. The case is made in the form of a cone. In the manufacturing process, a casting method is used.
If you see “gutter funnel 100” in the product description, you can be sure that this is the model you are describing, the number of which indicates the diameter of the nozzle. This characteristic is one of the main when choosing the components of the drainage system.
Another roof funnel manufacturer is Abbex. There are many models in the assortment line. Among others, TERMOCLIP type WB should be highlighted. The casing is based on low-pressure polyethylene; it is resistant to ultraviolet, weathering and radiation in the range from -50 to +80 ° .
The installation of such a product can be carried out on the roof of the deposited material according to the type of roofing material or technoelast. The diameters of the drain funnel range from 90 to 110 mm. The diameter of the base is 455 mm. The height can reach 450 mm, while the smallest value is 160 mm. Before choosing a specific model, you should evaluate the throughput of the product, in this case, this value can vary from 7.6 to 7.8 l / s.
Finally
When installing the funnel at the final stage, it is necessary to verify the efficiency of the drain and the tightness of the connections. To do this, a simple check is carried out: a bucket of water is splashed out at a distance of 2 m from the funnel. Then it remains only to observe how fast the water gets into the drain.